Cleanup in sample for spring-schema-registry-kafka-standalone

Use Horsham.SR10 directly instead of spring-cloud Hoxton

.gitignore

@@ -12,6 +12,7 @@ _site/
 .project
 .settings
 .springBeans
+.sts4-cache
 .DS_Store
 */.idea
 *.sw*
@@ -25,3 +26,4 @@ spring-xd-samples/*/xd
 dump.rdb
 .apt_generated
 artifacts
+.vscode

README.adoc

@@ -16,14 +16,8 @@ However, the recommended approach to build them is to pick the sample that you a
 
 ==== Source samples
 
-* Sample JDBC source using MySQL - MariaDB variant - (Kafka and Rabbit)
-
 * Source with dynamic destinations (Kafka and Rabbit)
 
-==== Sink samples
-
-* Simple JDBC sink using MariaDB (Kafka and Rabbit)
-
 ==== Processor samples
 
 * Basic StreamListener sample (Kafka and Rabbit)
@@ -63,8 +57,6 @@ A collection of various applications in stream processing using Spring Cloud Str
 * Sample with embedded Kafka
 * General testing patterns in Spring Cloud Stream
 
-==== Samples Acceptance Tests
+==== Function-based stream app samples
 
-This module is strictly used as an end to end acceptance test framework for the samples in this repo.
-By default, the tests are not run as part of a normal build.
-Please see the README in the acceptance test module for more details.
+Contains samples using the re-architected stream-applications and base functions included in https://github.com/spring-cloud/stream-applications. 

function-based-stream-app-samples/README.adoc

@@ -0,0 +1,4 @@
+= Function Based Stream Application Samples
+
+This directory contains samples using the re-architected stream-applications and base functions included in https://github.com/spring-cloud/stream-applications. 
+

function-based-stream-app-samples/couchbase-stream-applications/.gitignore

@@ -0,0 +1,33 @@
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

function-based-stream-app-samples/couchbase-stream-applications/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

function-based-stream-app-samples/couchbase-stream-applications/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

function-based-stream-app-samples/couchbase-stream-applications/README.adoc

@@ -0,0 +1,19 @@
+= Couchbase Stream Applications
+
+A sample Spring Cloud Stream Application and Consumer to demonstrate testing strategies using TestContainers.
+
+This project includes the following modules:
+
+* link:couchbase-consumer/[couchbase-consumer] - A Consumer to upsert documents into Couchbase
+* link:couchbase-sink/[couchbase-sink] - A Spring Cloud Stream sink application to invoke the consumer
+
+== Build
+
+```bash
+./mvnw clean install
+```
+
+=== Build container image and run integration tests
+```bash
+./mvnw install -Pintegration
+```

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/pom.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>io.spring.example</groupId>
+		<artifactId>couchbase-stream-applications</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+		<relativePath>..</relativePath>
+	</parent>
+	<groupId>io.spring.example</groupId>
+	<artifactId>couchbase-consumer</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>couchbase-consumer</name>
+	<description>Demo Couchbase Consumer</description>
+
+	<dependencies>
+		<dependency>
+			<groupId>com.couchbase.client</groupId>
+			<artifactId>java-client</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-configuration-processor</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud.fn</groupId>
+			<artifactId>config-common</artifactId>
+			<version>1.0.0-RC1</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>couchbase</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>junit-jupiter</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+</project>

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/src/main/java/io/spring/example/couchbase/consumer/CouchbaseConsumerConfiguration.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.consumer;
+
+import java.util.Optional;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import com.couchbase.client.java.Cluster;
+import com.couchbase.client.java.ReactiveBucket;
+import com.couchbase.client.java.ReactiveCollection;
+import com.couchbase.client.java.kv.MutationResult;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.expression.Expression;
+import org.springframework.lang.Nullable;
+import org.springframework.messaging.Message;
+
+@Configuration
+@EnableConfigurationProperties(CouchbaseConsumerProperties.class)
+public class CouchbaseConsumerConfiguration {
+
+	private static Logger logger = LoggerFactory.getLogger(CouchbaseConsumerConfiguration.class);
+
+	@Bean
+	public Consumer<Flux<Message<?>>> couchbaseConsumer(
+			Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction) {
+		return message -> couchbaseConsumerFunction.apply(message)
+				.subscribe(mutationResult ->
+						logger.debug("Processed " + message));
+	}
+
+	@Bean
+	public Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction(Cluster cluster,
+			CouchbaseConsumerProperties consumerProperties) {
+		return flux -> flux.flatMap(message -> {
+			logger.debug("Processing message " + message);
+			String bucketName = bucket(message, consumerProperties.getBucketExpression());
+			String key = key(message, consumerProperties.getKeyExpression());
+			ReactiveBucket bucket = cluster.bucket(bucketName).reactive();
+			ReactiveCollection collection = collection(message, consumerProperties.getCollectionExpression())
+					.map(name -> bucket.collection(name)).orElse(bucket.defaultCollection());
+			return collection.upsert(key, value(message, consumerProperties.getValueExpression()));
+		});
+	}
+
+	private String bucket(Message<?> message, Expression expression) {
+		return expression.getValue(message, String.class);
+	}
+
+	private String key(Message<?> message, Expression expression) {
+		return expression.getValue(message, String.class);
+	}
+
+	private Object value(Message<?> message, Expression expression) {
+		return expression.getValue(message);
+	}
+
+	private Optional<String> collection(Message<?> message, @Nullable Expression expression) {
+		return expression == null ? Optional.empty() : Optional.of(expression.getValue(message, String.class));
+	}
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/src/main/java/io/spring/example/couchbase/consumer/CouchbaseConsumerProperties.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.consumer;
+
+import javax.validation.constraints.NotNull;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.expression.Expression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.validation.annotation.Validated;
+
+@ConfigurationProperties("couchbase.consumer")
+@Validated
+public class CouchbaseConsumerProperties {
+
+	private static final String DEFAULT_VALUE_EXPRESSION = "payload";
+
+	private final SpelExpressionParser parser = new SpelExpressionParser();
+
+	/**
+	 * A SpEL expression to specify the bucket.
+	 */
+	private Expression bucketExpression;
+
+	/**
+	 * A SpEL expression to specify the key.
+	 */
+	private Expression keyExpression;
+
+	/**
+	 * A SpEL expression to specify the collection.
+	 */
+	private Expression collectionExpression;
+
+	/**
+	 * A SpEL expression to specify the value (default is payload).
+	 */
+	private Expression valueExpression = parser.parseExpression(DEFAULT_VALUE_EXPRESSION);
+
+	@NotNull(message = "'valueExpression' is required")
+	public Expression getValueExpression() {
+		return valueExpression;
+	}
+
+	public void setValueExpression(Expression valueExpression) {
+		this.valueExpression = valueExpression;
+	}
+
+	public Expression getCollectionExpression() {
+		return collectionExpression;
+	}
+
+	public void setCollectionExpression(Expression collectionExpression) {
+		this.collectionExpression = collectionExpression;
+	}
+
+	@NotNull(message = "'keyExpression' is required")
+	public Expression getKeyExpression() {
+		return keyExpression;
+	}
+
+	public void setKeyExpression(Expression keyExpression) {
+		this.keyExpression = keyExpression;
+	}
+
+	@NotNull(message = "'bucketExpression' is required")
+	public Expression getBucketExpression() {
+		return bucketExpression;
+	}
+
+	public void setBucketExpression(Expression bucketExpression) {
+		this.bucketExpression = bucketExpression;
+	}
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/src/test/java/io/spring/example/couchbase/consumer/CouchbaseConsumerTests.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.consumer;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import javax.annotation.PreDestroy;
+
+import com.couchbase.client.java.Bucket;
+import com.couchbase.client.java.Cluster;
+import com.couchbase.client.java.kv.MutationResult;
+import io.spring.example.couchbase.consumer.domain.User;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.couchbase.BucketDefinition;
+import org.testcontainers.couchbase.CouchbaseContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import reactor.core.publisher.Flux;
+import reactor.test.StepVerifier;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.GenericMessage;
+import org.springframework.messaging.support.MessageBuilder;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+@Testcontainers
+public class CouchbaseConsumerTests {
+
+	@Container
+	static CouchbaseContainer container = new CouchbaseContainer("couchbase/server:6.6.0")
+			.withBucket(new BucketDefinition("test"));
+
+	private ApplicationContextRunner applicationContextRunner;
+
+	@BeforeEach
+	void setup() {
+		applicationContextRunner = new ApplicationContextRunner()
+				.withUserConfiguration(TestConfig.class)
+				.withPropertyValues(
+						"spring.couchbase.connection-string=" + container.getConnectionString(),
+						"spring.couchbase.username=" + container.getUsername(),
+						"spring.couchbase.password=" + container.getPassword());
+	}
+
+	@Test
+	void keyExpressionRequired() {
+		assertThatExceptionOfType(RuntimeException.class).isThrownBy(
+				() -> applicationContextRunner.withPropertyValues("couchbase.consumer.bucket-expression='test'")
+						.run(context -> context.start()))
+				.havingRootCause()
+				.withMessageContaining("'keyExpression' is required");
+	}
+
+	@Test
+	void singleUpsert() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression='test'",
+				"couchbase.consumer.keyExpression=payload.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					String bucketName = properties.getBucketExpression().getValue(String.class);
+					Cluster cluster = context.getBean(Cluster.class);
+					Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction = context
+							.getBean("couchbaseConsumerFunction", Function.class);
+					StepVerifier.create(couchbaseConsumerFunction
+							.apply(Flux.just(new GenericMessage<>(new User("David", "david@david.com")))))
+							.expectNextMatches(
+									mutationResult -> mutationResult.mutationToken().get().bucketName().equals(
+											bucketName))
+							.verifyComplete();
+
+					User saved = cluster.bucket(bucketName).defaultCollection().get("david@david.com")
+							.contentAs(User.class);
+					assertThat(saved.getName()).isEqualTo("David");
+				});
+	}
+
+	@Test
+	void singleUpsertConsumer() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression='test'",
+				"couchbase.consumer.keyExpression=payload.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					Cluster cluster = context.getBean(Cluster.class);
+					String bucketName = properties.getBucketExpression().getValue(String.class);
+					Consumer<Flux<Message<?>>> couchbaseConsumer = context
+							.getBean("couchbaseConsumer", Consumer.class);
+					couchbaseConsumer.accept(Flux.just(new GenericMessage<>(new User("David", "david@david.com"))));
+
+					User saved = cluster.bucket(bucketName).defaultCollection().get("david@david.com")
+							.contentAs(User.class);
+					assertThat(saved.getName()).isEqualTo("David");
+				});
+	}
+
+	@Test
+	void multipleUpsert() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression='test'",
+				"couchbase.consumer.keyExpression=payload.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					Cluster cluster = context.getBean(Cluster.class);
+					String bucketName = properties.getBucketExpression().getValue(String.class);
+					User user1 = new User("David", "david@david.com");
+					User user2 = new User("Nanette", "nanette@nanette.com");
+					User user3 = new User("Soby", "soby@soby.com");
+
+					Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction = context
+							.getBean("couchbaseConsumerFunction", Function.class);
+					StepVerifier.create(couchbaseConsumerFunction
+							.apply(Flux.just(
+									new GenericMessage<>(user1),
+									new GenericMessage<>(user2),
+									new GenericMessage<>(user3))))
+							.expectNextMatches(
+									mutationResult -> mutationResult.mutationToken().get().bucketName().equals(
+											bucketName))
+							.expectNextMatches(
+									mutationResult -> mutationResult.mutationToken().get().bucketName().equals(
+											bucketName))
+							.expectNextMatches(
+									mutationResult -> mutationResult.mutationToken().get().bucketName().equals(
+											bucketName))
+							.verifyComplete();
+
+					List<User> users = cluster.query("SELECT name,email from test").rowsAs(User.class);
+					assertThat(users).containsExactlyInAnyOrder(user1, user2, user3);
+				});
+	}
+
+	@Test
+	void customBucketExpression() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression=headers.bucketName",
+				"couchbase.consumer.keyExpression=payload.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					Cluster cluster = context.getBean(Cluster.class);
+					String bucketName = "test";
+					MessageBuilder.withPayload(new User("David", "david@david.com"))
+							.copyHeaders(Collections.singletonMap("bucketName", bucketName)).build();
+					Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction = context
+							.getBean("couchbaseConsumerFunction", Function.class);
+					Message<?> message = MessageBuilder.withPayload(new User("David", "david@david.com"))
+							.copyHeaders(Collections.singletonMap("bucketName", bucketName)).build();
+					StepVerifier.create(couchbaseConsumerFunction.apply(Flux.just(message)))
+							.expectNextMatches(
+									(MutationResult mutationResult) -> mutationResult.mutationToken().get().bucketName()
+											.equals(
+													bucketName))
+							.verifyComplete();
+
+					User saved = cluster.bucket(bucketName).defaultCollection().get("david@david.com")
+							.contentAs(User.class);
+					assertThat(saved.getName()).isEqualTo("David");
+				});
+	}
+
+	@Test
+	void customValueExpression() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression='test'",
+				"couchbase.consumer.valueExpression=payload.user",
+				"couchbase.consumer.keyExpression=payload.user.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					Cluster cluster = context.getBean(Cluster.class);
+					String bucketName = properties.getBucketExpression().getValue(String.class);
+					Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction = context
+							.getBean("couchbaseConsumerFunction", Function.class);
+					StepVerifier.create(couchbaseConsumerFunction
+							.apply(Flux
+									.just(new GenericMessage<>(
+											Collections.singletonMap("user", new User("David", "david@david.com"))))))
+							.expectNextMatches(
+									mutationResult -> mutationResult.mutationToken().get().bucketName().equals(
+											bucketName))
+							.verifyComplete();
+
+					Bucket bucket = cluster.bucket(bucketName);
+					User saved = cluster.bucket(bucketName).defaultCollection().get("david@david.com")
+							.contentAs(User.class);
+					assertThat(saved.getName()).isEqualTo("David");
+				});
+	}
+
+	@Test
+	void bucketDoesNotExistShouldThrowException() {
+		applicationContextRunner.withPropertyValues(
+				"couchbase.consumer.bucketExpression='users'",
+				"couchbase.consumer.keyExpression=payload.email")
+				.run(context -> {
+					CouchbaseConsumerProperties properties = context.getBean(CouchbaseConsumerProperties.class);
+					Function<Flux<Message<?>>, Flux<MutationResult>> couchbaseConsumerFunction = context
+							.getBean("couchbaseConsumerFunction", Function.class);
+					StepVerifier.create(couchbaseConsumerFunction
+							.apply(Flux.just(new GenericMessage<>(new User("David", "david@david.com")))))
+							.expectErrorMatches(e -> e.toString().contains("BUCKET_NOT_AVAILABLE"))
+							.verify();
+				});
+	}
+
+	@SpringBootApplication
+	static class TestConfig {
+		@Autowired
+		Cluster cluster;
+
+		@PreDestroy
+		public void destroy() {
+			cluster.disconnect();
+		}
+	}
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/src/test/java/io/spring/example/couchbase/consumer/domain/User.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.consumer.domain;
+
+import java.util.Objects;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class User {
+	private String name;
+
+	private String email;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public String getEmail() {
+		return email;
+	}
+
+	public void setEmail(String email) {
+		this.email = email;
+	}
+
+	public User() {
+	}
+
+	public User(String name, String email) {
+		this.name = name;
+		this.email = email;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		User user = (User) o;
+		return Objects.equals(name, user.name) &&
+				Objects.equals(email, user.email);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(name, email);
+	}
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-consumer/src/test/resources/logback-test.xml

@@ -0,0 +1,14 @@
+<configuration>
+	<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="info">
+		<appender-ref ref="STDOUT"/>
+	</root>
+
+	<logger name="org.testcontainers" level="INFO"/>
+	<logger name="com.github.dockerjava" level="WARN"/>
+</configuration>

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/README.adoc

@@ -0,0 +1,22 @@
+== Options
+
+The **$$couchbase$$** $$sink$$ has the following options:
+
+
+//tag::configuration-properties[]
+Properties grouped by prefix:
+
+
+=== couchbase.consumer
+
+$$bucket-expression$$:: $$A SpEL expression to specify the bucket.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$collection-expression$$:: $$A SpEL expression to specify the collection.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$key-expression$$:: $$A SpEL expression to specify the key.$$ *($$Expression$$, default: `$$<none>$$`)*
+$$value-expression$$:: $$A SpEL expression to specify the value (default is payload).$$ *($$Expression$$, default: `$$<none>$$`)*
+
+=== spring.couchbase
+
+$$connection-string$$:: $$Connection string used to locate the Couchbase cluster.$$ *($$String$$, default: `$$<none>$$`)*
+$$password$$:: $$Cluster password.$$ *($$String$$, default: `$$<none>$$`)*
+$$username$$:: $$Cluster username.$$ *($$String$$, default: `$$<none>$$`)*
+//end::configuration-properties[]

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/pom.xml

@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>io.spring.example</groupId>
+		<artifactId>couchbase-stream-applications</artifactId>
+		<version>0.0.1-SNAPSHOT</version>
+		<relativePath>..</relativePath>
+	</parent>
+	<groupId>io.spring.example</groupId>
+	<artifactId>couchbase-sink</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>couchbase-sink</name>
+	<description>Demo Couchbase Sink</description>
+
+	<dependencies>
+		<dependency>
+			<groupId>io.spring.example</groupId>
+			<artifactId>couchbase-consumer</artifactId>
+			<version>0.0.1-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream-binder-kafka</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream</artifactId>
+			<type>test-jar</type>
+			<classifier>test-binder</classifier>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>couchbase</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>kafka</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testcontainers</groupId>
+			<artifactId>junit-jupiter</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud.stream.app</groupId>
+			<artifactId>stream-applications-test-support</artifactId>
+			<version>3.0.0</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<profiles>
+		<profile>
+			<id>integration</id>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.apache.maven.plugins</groupId>
+						<artifactId>maven-failsafe-plugin</artifactId>
+						<dependencies>
+							<dependency>
+								<groupId>org.junit.jupiter</groupId>
+								<artifactId>junit-jupiter-engine</artifactId>
+								<version>5.7.0</version>
+							</dependency>
+						</dependencies>
+
+						<configuration>
+							<groups>integration</groups>
+							<includes>
+								<include>*IntegrationTests.java</include>
+							</includes>
+							<failIfNoTests>true</failIfNoTests>
+							<skipITs>false</skipITs>
+						</configuration>
+					</plugin>
+					<plugin>
+						<groupId>org.springframework.boot</groupId>
+						<artifactId>spring-boot-maven-plugin</artifactId>
+						<executions>
+							<execution>
+								<id>build-image</id>
+								<goals>
+									<goal>build-image</goal>
+								</goals>
+								<phase>pre-integration-test</phase>
+							</execution>
+						</executions>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
+	</profiles>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+			<plugin>
+				<groupId>org.springframework.cloud</groupId>
+				<artifactId>spring-cloud-dataflow-apps-docs-plugin</artifactId>
+				<version>1.1.0-SNAPSHOT</version>
+				<executions>
+					<execution>
+						<id>generate-documentation</id>
+						<phase>verify</phase>
+						<goals>
+							<goal>generate-documentation</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/main/java/io/spring/example/couchbase/sink/CouchbaseSinkApplication.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 the original author or authors.
+ * Copyright 2020-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,16 +14,18 @@
  * limitations under the License.
  */
 
-package multibinder;
+package io.spring.example.couchbase.sink;
+
+import io.spring.example.couchbase.consumer.CouchbaseConsumerConfiguration;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Import;
 
 @SpringBootApplication
-public class MultibinderApplication {
-
-	public static void main(String[] args) {
-		SpringApplication.run(MultibinderApplication.class, args);
+@Import(CouchbaseConsumerConfiguration.class)
+public class CouchbaseSinkApplication {
+	public static void main(String... args) {
+		new SpringApplication(CouchbaseSinkApplication.class).run(args);
 	}
-
 }

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/main/resources/META-INF/dataflow-configuration-metadata.properties

@@ -0,0 +1,3 @@
+configuration-properties.classes=io.spring.example.couchbase.consumer.CouchbaseConsumerProperties, \
+  org.springframework.boot.autoconfigure.couchbase.CouchbaseProperties
+

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/main/resources/application.properties

@@ -0,0 +1,3 @@
+management.endpoints.web.exposure.include=health,info,bindings
+spring.cloud.function.definition=couchbaseConsumer
+spring.cloud.stream.function.bindings.couchbaseConsumer-in-0=input

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/test/java/io/spring/example/couchbase/sink/CouchbaseSinkApplicationTests.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.sink;
+
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
+
+import com.couchbase.client.java.Cluster;
+import io.spring.example.couchbase.sink.domain.User;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.couchbase.BucketDefinition;
+import org.testcontainers.couchbase.CouchbaseContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.stream.binder.test.InputDestination;
+import org.springframework.cloud.stream.binder.test.TestChannelBinderConfiguration;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.messaging.support.GenericMessage;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+
+@Testcontainers
+public class CouchbaseSinkApplicationTests {
+	@Container
+	static CouchbaseContainer container = new CouchbaseContainer("couchbase/server:6.6.0")
+			.withBucket(new BucketDefinition("test"));
+
+	static Map<String, Object> connectProperties = new HashMap<>();
+
+	@BeforeAll
+	static void initialize() {
+		connectProperties.put("spring.couchbase.connection-string", container.getConnectionString());
+		connectProperties.put("spring.couchbase.username", container.getUsername());
+		connectProperties.put("spring.couchbase.password", container.getPassword());
+	}
+
+	@Test
+	void test() {
+		try (ConfigurableApplicationContext context = new SpringApplicationBuilder(
+				TestChannelBinderConfiguration
+						.getCompleteConfiguration(CouchbaseSinkApplication.class))
+								.web(WebApplicationType.NONE)
+								.properties(connectProperties)
+								.run("--couchbase.consumer.bucketExpression='test'",
+										"--couchbase.consumer.keyExpression=payload.email")) {
+			InputDestination inputDestination = context.getBean(InputDestination.class);
+			Cluster cluster = context.getBean(Cluster.class);
+			inputDestination.send(new GenericMessage<>(new User("Bart Simpson", "bart@simpsons.com")));
+
+			await().atMost(Duration.ofSeconds(10)).untilAsserted(() -> {
+				User user = cluster.bucket("test").defaultCollection().get("bart@simpsons.com")
+						.contentAs(User.class);
+				assertThat(user).isNotNull();
+				assertThat(user.getName()).isEqualTo("Bart Simpson");
+			});
+		}
+	}
+
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/test/java/io/spring/example/couchbase/sink/domain/User.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.sink.domain;
+
+import java.util.Objects;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public class User {
+	private String name;
+
+	private String email;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public String getEmail() {
+		return email;
+	}
+
+	public void setEmail(String email) {
+		this.email = email;
+	}
+
+	public User() {
+	}
+
+	public User(String name, String email) {
+		this.name = name;
+		this.email = email;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (this == o) {
+			return true;
+		}
+		if (o == null || getClass() != o.getClass()) {
+			return false;
+		}
+		User user = (User) o;
+		return Objects.equals(name, user.name) &&
+				Objects.equals(email, user.email);
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(name, email);
+	}
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/test/java/io/spring/example/couchbase/sink/integration/CouchbaseSinkIntegrationTests.java

@@ -0,0 +1,108 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.couchbase.sink.integration;
+
+import java.time.Duration;
+
+import com.couchbase.client.java.Cluster;
+import com.couchbase.client.java.ClusterOptions;
+import com.couchbase.client.java.kv.ExistsResult;
+import io.spring.example.couchbase.sink.domain.User;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.wait.strategy.Wait;
+import org.testcontainers.couchbase.BucketDefinition;
+import org.testcontainers.couchbase.CouchbaseContainer;
+import org.testcontainers.couchbase.CouchbaseService;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.shaded.com.fasterxml.jackson.core.JsonProcessingException;
+import org.testcontainers.shaded.com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.cloud.stream.app.test.integration.StreamAppContainer;
+import org.springframework.cloud.stream.app.test.integration.TestTopicSender;
+import org.springframework.cloud.stream.app.test.integration.junit.jupiter.KafkaStreamAppTest;
+import org.springframework.cloud.stream.app.test.integration.kafka.KafkaConfig;
+import org.springframework.cloud.stream.app.test.integration.kafka.KafkaStreamAppContainer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+import static org.springframework.cloud.stream.app.test.integration.AppLog.appLog;
+
+@KafkaStreamAppTest
+@Tag("integration")
+public class CouchbaseSinkIntegrationTests {
+
+	static StreamAppContainer sink = new KafkaStreamAppContainer("couchbase-sink:0.0.1-SNAPSHOT");
+
+	@Container
+	static CouchbaseContainer container = new CouchbaseContainer("couchbase/server:6.6.0")
+			.withEnabledServices(CouchbaseService.INDEX, CouchbaseService.KV, CouchbaseService.QUERY,
+					CouchbaseService.SEARCH)
+			.withNetwork(KafkaConfig.kafka.getNetwork())
+			.withNetworkAliases("couchbase-server")
+			.withBucket(new BucketDefinition("test"));
+
+	static Cluster cluster;
+
+	@Autowired
+	TestTopicSender testTopicSender;
+
+	@BeforeAll
+	static void initialize() {
+		await().until(() -> container.isRunning());
+		String connectionString = "couchbase://couchbase-server";
+		sink.waitingFor(Wait.forLogMessage(".*Started CouchbaseSink.*", 1))
+				.withLogConsumer(appLog("couchbase-sink"))
+				.withCommand(
+						"--spring.couchbase.connection-string=couchbase://couchbase-server",
+						"--spring.couchbase.username=" + container.getUsername(),
+						"--spring.couchbase.password=" + container.getPassword(),
+						"--couchbase.consumer.bucket-expression='test'",
+						"--couchbase.consumer.key-expression=payload.email")
+				.start();
+
+		cluster = Cluster.connect(container.getConnectionString(),
+				ClusterOptions.clusterOptions(container.getUsername(), container.getPassword()));
+	}
+
+	@AfterAll
+	static void stop() {
+		sink.stop();
+	}
+
+	@Test
+	void test() throws JsonProcessingException {
+		ObjectMapper objectMapper = new ObjectMapper();
+		testTopicSender.send(sink.getInputDestination(),
+				objectMapper.writeValueAsString(new User("Bart Simpson", "bart@simpsons.com")));
+
+		await().atMost(Duration.ofSeconds(10)).untilAsserted(() -> {
+			ExistsResult result = cluster.bucket("test").defaultCollection().exists("bart@simpsons.com");
+			assertThat(result.exists()).isTrue();
+		});
+
+		User user = objectMapper.readValue(
+				cluster.bucket("test").defaultCollection().get("bart@simpsons.com").contentAs(String.class),
+				User.class);
+
+		assertThat(user.getName()).isEqualTo("Bart Simpson");
+	}
+
+}

function-based-stream-app-samples/couchbase-stream-applications/couchbase-sink/src/test/resources/logback-test.xml

@@ -0,0 +1,14 @@
+<configuration>
+	<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+		<encoder>
+			<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger - %msg%n</pattern>
+		</encoder>
+	</appender>
+
+	<root level="info">
+		<appender-ref ref="STDOUT"/>
+	</root>
+
+	<logger name="org.testcontainers" level="INFO"/>
+	<logger name="com.github.dockerjava" level="WARN"/>
+</configuration>

function-based-stream-app-samples/couchbase-stream-applications/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/couchbase-stream-applications/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/couchbase-stream-applications/pom.xml

@@ -0,0 +1,95 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.4.0</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.spring.example</groupId>
+	<artifactId>couchbase-stream-applications</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>couchbase-stream-applications</name>
+	<packaging>pom</packaging>
+	<description>Demo Stream Applications project for Couchhbase</description>
+
+	<properties>
+		<java.version>8</java.version>
+		<spring-cloud.version>2020.0.0-M5</spring-cloud.version>
+		<playtika-testcontainers.version>1.86</playtika-testcontainers.version>
+		<couchbase-java-client.version>3.0.10</couchbase-java-client.version>
+		<test-containers.version>1.15.1</test-containers.version>
+	</properties>
+
+
+	<modules>
+		<module>couchbase-consumer</module>
+		<module>couchbase-sink</module>
+	</modules>
+	
+	<dependencyManagement>
+		<dependencies>
+			<dependency>
+				<groupId>com.couchbase.client</groupId>
+				<artifactId>java-client</artifactId>
+				<version>${couchbase-java-client.version}</version>
+			</dependency>
+			<dependency>
+				<groupId>org.springframework.cloud</groupId>
+				<artifactId>spring-cloud-dependencies</artifactId>
+				<version>${spring-cloud.version}</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+			<dependency>
+				<groupId>org.testcontainers</groupId>
+				<artifactId>testcontainers-bom</artifactId>
+				<version>${test-containers.version}</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+
+	<repositories>
+		<repository>
+			<id>spring-milestones</id>
+			<name>Spring Milestones</name>
+			<url>https://repo.spring.io/milestone</url>
+		</repository>
+	</repositories>
+
+	<pluginRepositories>
+		<pluginRepository>
+			<id>spring-milestones</id>
+			<name>Spring Milestones</name>
+			<url>https://repo.spring.io/milestone</url>
+		</pluginRepository>
+
+		<pluginRepository>
+			<id>spring-snapshots</id>
+			<name>Spring Snapshots</name>
+			<url>https://repo.spring.io/snapshot</url>
+			<snapshots>
+				<enabled>true</enabled>
+			</snapshots>
+		</pluginRepository>
+	</pluginRepositories>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<configuration>
+					<groups>!integration</groups>
+					<skipTests>true</skipTests>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+
+</project>

function-based-stream-app-samples/image-thumbnail-samples/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,122 @@
+
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+	private static final String WRAPPER_VERSION = "0.5.6";
+
+	/**
+	 * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+	 */
+	private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+			+ WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+	/**
+	 * Path to the maven-wrapper.properties file, which might contain a downloadUrl property
+	 * to use instead of the default one.
+	 */
+	private static final String MAVEN_WRAPPER_PROPERTIES_PATH = ".mvn/wrapper/maven-wrapper.properties";
+
+	/**
+	 * Path where the maven-wrapper.jar will be saved to.
+	 */
+	private static final String MAVEN_WRAPPER_JAR_PATH = ".mvn/wrapper/maven-wrapper.jar";
+
+	/**
+	 * Name of the property which should be used to override the default download url for the
+	 * wrapper.
+	 */
+	private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+	public static void main(String args[]) {
+		System.out.println("- Downloader started");
+		File baseDirectory = new File(args[0]);
+		System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+		// If the maven-wrapper.properties exists, read it and check if it contains a custom
+		// wrapperUrl parameter.
+		File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+		String url = DEFAULT_DOWNLOAD_URL;
+		if (mavenWrapperPropertyFile.exists()) {
+			FileInputStream mavenWrapperPropertyFileInputStream = null;
+			try {
+				mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+				Properties mavenWrapperProperties = new Properties();
+				mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+				url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+			}
+			catch (IOException e) {
+				System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+			}
+			finally {
+				try {
+					if (mavenWrapperPropertyFileInputStream != null) {
+						mavenWrapperPropertyFileInputStream.close();
+					}
+				}
+				catch (IOException e) {
+					// Ignore ...
+				}
+			}
+		}
+		System.out.println("- Downloading from: " + url);
+
+		File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+		if (!outputFile.getParentFile().exists()) {
+			if (!outputFile.getParentFile().mkdirs()) {
+				System.out.println(
+						"- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+			}
+		}
+		System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+		try {
+			downloadFileFromURL(url, outputFile);
+			System.out.println("Done");
+			System.exit(0);
+		}
+		catch (Throwable e) {
+			System.out.println("- Error downloading");
+			e.printStackTrace();
+			System.exit(1);
+		}
+	}
+
+	private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+		if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+			String username = System.getenv("MVNW_USERNAME");
+			char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+			Authenticator.setDefault(new Authenticator() {
+				@Override
+				protected PasswordAuthentication getPasswordAuthentication() {
+					return new PasswordAuthentication(username, password);
+				}
+			});
+		}
+		URL website = new URL(urlString);
+		ReadableByteChannel rbc;
+		rbc = Channels.newChannel(website.openStream());
+		FileOutputStream fos = new FileOutputStream(destination);
+		fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+		fos.close();
+		rbc.close();
+	}
+
+}

function-based-stream-app-samples/image-thumbnail-samples/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

function-based-stream-app-samples/image-thumbnail-samples/README.adoc

@@ -0,0 +1,15 @@
+= Thumbnail Demo
+
+image:img/thumbnail-files.png[]
+
+This project demonstrates the use of https://github.com/spring-cloud/stream-applications/tree/master/functions/function/http-request-function[HttpRequestFunction] and the https://github.com/spring-cloud/stream-applications/tree/master/applications/processor/http-request-processor[HTTP Request Processor] with the following modules:
+
+* link:image-thumbnail-processor/[image-thumbnail-processor] - A simple function to create thumbnails from JPEG files.
+* link:image-thumbnail-web/[image-thumbnail-web] - A Spring Boot web application using the HTTP Request Function
+* link:image-thumbnail-stream-sample/[image-thumbnail-stream-sample] - A Spring Cloud Stream Sink Application used in a Spring Cloud Stream application demonstrating the HTTP Request Processor
+
+== Build
+
+```bash
+./mvnw clean install
+```

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,122 @@
+
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+	private static final String WRAPPER_VERSION = "0.5.6";
+
+	/**
+	 * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+	 */
+	private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+			+ WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+	/**
+	 * Path to the maven-wrapper.properties file, which might contain a downloadUrl property
+	 * to use instead of the default one.
+	 */
+	private static final String MAVEN_WRAPPER_PROPERTIES_PATH = ".mvn/wrapper/maven-wrapper.properties";
+
+	/**
+	 * Path where the maven-wrapper.jar will be saved to.
+	 */
+	private static final String MAVEN_WRAPPER_JAR_PATH = ".mvn/wrapper/maven-wrapper.jar";
+
+	/**
+	 * Name of the property which should be used to override the default download url for the
+	 * wrapper.
+	 */
+	private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+	public static void main(String args[]) {
+		System.out.println("- Downloader started");
+		File baseDirectory = new File(args[0]);
+		System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+		// If the maven-wrapper.properties exists, read it and check if it contains a custom
+		// wrapperUrl parameter.
+		File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+		String url = DEFAULT_DOWNLOAD_URL;
+		if (mavenWrapperPropertyFile.exists()) {
+			FileInputStream mavenWrapperPropertyFileInputStream = null;
+			try {
+				mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+				Properties mavenWrapperProperties = new Properties();
+				mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+				url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+			}
+			catch (IOException e) {
+				System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+			}
+			finally {
+				try {
+					if (mavenWrapperPropertyFileInputStream != null) {
+						mavenWrapperPropertyFileInputStream.close();
+					}
+				}
+				catch (IOException e) {
+					// Ignore ...
+				}
+			}
+		}
+		System.out.println("- Downloading from: " + url);
+
+		File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+		if (!outputFile.getParentFile().exists()) {
+			if (!outputFile.getParentFile().mkdirs()) {
+				System.out.println(
+						"- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+			}
+		}
+		System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+		try {
+			downloadFileFromURL(url, outputFile);
+			System.out.println("Done");
+			System.exit(0);
+		}
+		catch (Throwable e) {
+			System.out.println("- Error downloading");
+			e.printStackTrace();
+			System.exit(1);
+		}
+	}
+
+	private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+		if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+			String username = System.getenv("MVNW_USERNAME");
+			char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+			Authenticator.setDefault(new Authenticator() {
+				@Override
+				protected PasswordAuthentication getPasswordAuthentication() {
+					return new PasswordAuthentication(username, password);
+				}
+			});
+		}
+		URL website = new URL(urlString);
+		ReadableByteChannel rbc;
+		rbc = Channels.newChannel(website.openStream());
+		FileOutputStream fos = new FileOutputStream(destination);
+		fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+		fos.close();
+		rbc.close();
+	}
+
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/README.adoc

@@ -0,0 +1,10 @@
+= Thumbnail Processor
+
+A plain (no dependencies) Java Function that creates a thumbnail from an JPEG image.
+See https://stackoverflow.com/a/39313627/1743446.
+
+== Build
+
+```
+./mwnw clean install
+```

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/mvnw

@@ -0,0 +1,322 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ]; then
+
+  if [ -f /etc/mavenrc ]; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ]; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false
+darwin=false
+mingw=false
+case "$(uname)" in
+CYGWIN*) cygwin=true ;;
+MINGW*) mingw=true ;;
+Darwin*)
+  darwin=true
+  # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+  # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+  if [ -z "$JAVA_HOME" ]; then
+    if [ -x "/usr/libexec/java_home" ]; then
+      export JAVA_HOME="$(/usr/libexec/java_home)"
+    else
+      export JAVA_HOME="/Library/Java/Home"
+    fi
+  fi
+  ;;
+esac
+
+if [ -z "$JAVA_HOME" ]; then
+  if [ -r /etc/gentoo-release ]; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+if [ -z "$M2_HOME" ]; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ]; do
+    ls=$(ls -ld "$PRG")
+    link=$(expr "$ls" : '.*-> \(.*\)$')
+    if expr "$link" : '/.*' >/dev/null; then
+      PRG="$link"
+    else
+      PRG="$(dirname "$PRG")/$link"
+    fi
+  done
+
+  saveddir=$(pwd)
+
+  M2_HOME=$(dirname "$PRG")/..
+
+  # make it fully qualified
+  M2_HOME=$(cd "$M2_HOME" && pwd)
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --unix "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --unix "$CLASSPATH")
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="$( (
+      cd "$M2_HOME"
+      pwd
+    ))"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="$( (
+      cd "$JAVA_HOME"
+      pwd
+    ))"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="$(which javac)"
+  if [ -n "$javaExecutable" ] && ! [ "$(expr \"$javaExecutable\" : '\([^ ]*\)')" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=$(which readlink)
+    if [ ! $(expr "$readLink" : '\([^ ]*\)') = "no" ]; then
+      if $darwin; then
+        javaHome="$(dirname \"$javaExecutable\")"
+        javaExecutable="$(cd \"$javaHome\" && pwd -P)/javac"
+      else
+        javaExecutable="$(readlink -f \"$javaExecutable\")"
+      fi
+      javaHome="$(dirname \"$javaExecutable\")"
+      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ]; then
+  if [ -n "$JAVA_HOME" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="$(which java)"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ]; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]; then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ]; do
+    if [ -d "$wdir"/.mvn ]; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=$(
+        cd "$wdir/.."
+        pwd
+      )
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' <"$1")"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(pwd)")
+if [ -z "$BASE_DIR" ]; then
+  exit 1
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Found .mvn/wrapper/maven-wrapper.jar"
+  fi
+else
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+  fi
+  if [ -n "$MVNW_REPOURL" ]; then
+    jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  else
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  fi
+  while IFS="=" read key value; do
+    case "$key" in wrapperUrl)
+      jarUrl="$value"
+      break
+      ;;
+    esac
+  done <"$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Downloading from: $jarUrl"
+  fi
+  wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+  if $cygwin; then
+    wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+  fi
+
+  if command -v wget >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found wget ... using wget"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      wget "$jarUrl" -O "$wrapperJarPath"
+    else
+      wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+    fi
+  elif command -v curl >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found curl ... using curl"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      curl -o "$wrapperJarPath" "$jarUrl" -f
+    else
+      curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+    fi
+
+  else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Falling back to using Java to download"
+    fi
+    javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+    # For Cygwin, switch paths to Windows format before running javac
+    if $cygwin; then
+      javaClass=$(cygpath --path --windows "$javaClass")
+    fi
+    if [ -e "$javaClass" ]; then
+      if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Compiling MavenWrapperDownloader.java ..."
+        fi
+        # Compiling the Java class
+        ("$JAVA_HOME/bin/javac" "$javaClass")
+      fi
+      if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        # Running the downloader
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Running MavenWrapperDownloader.java ..."
+        fi
+        ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+      fi
+    fi
+  fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --path --windows "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --path --windows "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --windows "$CLASSPATH")
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=$(cygpath --path --windows "$MAVEN_PROJECTBASEDIR")
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/pom.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.4.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.spring.cloud.stream.sample</groupId>
+	<artifactId>image-thumbnail-processor</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>image-thumbnail-processor</name>
+	<description>Thumbnail processor</description>
+
+	<properties>
+		<java.version>8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter</artifactId>
+			<version>5.6.2</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.assertj</groupId>
+			<artifactId>assertj-core</artifactId>
+			<version>3.16.1</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-core</artifactId>
+			<version>5.2.8.RELEASE</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+</project>

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/src/main/java/io/spring/example/image/thumbnail/processor/ThumbnailProcessor.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.image.thumbnail.processor;
+
+import java.awt.AlphaComposite;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.util.function.Function;
+
+import javax.imageio.ImageIO;
+
+public class ThumbnailProcessor implements Function<byte[], byte[]> {
+	ImageScaler imageScaler = new ImageScaler();
+
+	public byte[] apply(byte[] bytes) {
+		return imageScaler
+				.resize(new ByteArrayInputStream(bytes), 100, 100, "JPEG").toByteArray();
+	}
+
+	/**
+	 * From https://stackoverflow.com/a/39313627/1743446
+	 */
+	static class ImageScaler {
+
+		public ByteArrayOutputStream resize(InputStream inputStream, int IMG_WIDTH,
+				int IMG_HEIGHT, String format) {
+			ByteArrayOutputStream bos = new ByteArrayOutputStream();
+			try {
+				BufferedImage originalImage = ImageIO.read(inputStream);
+				int type = originalImage.getType() == 0 ? BufferedImage.TYPE_INT_ARGB
+						: originalImage.getType();
+				BufferedImage resizedImage = new BufferedImage(IMG_WIDTH, IMG_HEIGHT,
+						type);
+
+				Graphics2D g = resizedImage.createGraphics();
+				g.drawImage(originalImage, 0, 0, IMG_WIDTH, IMG_HEIGHT, null);
+				g.dispose();
+				g.setComposite(AlphaComposite.Src);
+
+				g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
+						RenderingHints.VALUE_INTERPOLATION_BILINEAR);
+				g.setRenderingHint(RenderingHints.KEY_RENDERING,
+						RenderingHints.VALUE_RENDER_QUALITY);
+				g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
+						RenderingHints.VALUE_ANTIALIAS_ON);
+
+				ImageIO.write(resizedImage, format, bos);
+			}
+			catch (Exception e) {
+				throw new RuntimeException(e.getMessage(), e);
+			}
+			return bos;
+		}
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-processor/src/test/java/io/spring/example/image/thumbnail/processor/ThumbnailProcessorTests.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.image.thumbnail.processor;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ThumbnailProcessorTests {
+	@TempDir
+	File tempDir;
+
+	@Test
+	void test() throws IOException {
+		Resource resource = new ClassPathResource("firetruck.jpg");
+		byte[] data = readAllBytes(resource);
+		byte[] thumbnail = new ThumbnailProcessor().apply(data);
+		Path path = Paths.get(tempDir.getAbsolutePath(), "thumbnail.jpg");
+		Files.write(path, thumbnail);
+		assertThat(Files.exists(path)).isTrue();
+	}
+
+	private byte[] readAllBytes(Resource resource) throws IOException {
+		InputStream is = resource.getInputStream();
+		byte[] bytes = new byte[is.available()];
+		is.read(bytes);
+		return bytes;
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/README.adoc

@@ -0,0 +1,89 @@
+= Thumbnail Stream Sample
+
+== Run with docker-compose
+
+If you have docker installed and running, this is the easiest way to run this sample.
+
+=== Build the link:image-thumbnail-sink[] 
+
+Build the docker image to register with the local Docker daemon. 
+
+```
+cd image-thumbnail-sink
+./mvnw clean package jib:dockerBuild
+```
+=== Create input and output directories `images` and `thumbnails`.
+These names are referenced in link:docker-compose-apps.yml[]
+
+```
+cd image-thumbnail-stream-sample
+mkdir images thumbnails
+```
+
+=== Start the containers
+
+```
+docker-compose -f docker-compose-kafka.yml -f docker-compose-apps.yml up
+```
+
+Proceed to xref:Create_Some_Data[Create Some Data]
+
+== Run standalone
+We will use this sink in a streaming application that reads a text file containing image URLs and create a thumbnail file for each image: `file-source | http-request-processor | image-thumbnail-sink`
+
+=== Download the pre-packaged Source and Processor applications:
+
+```
+wget https://repo.spring.io/snapshot/org/springframework/cloud/stream/app/file-source-kafka/3.0.0-SNAPSHOT/file-source-kafka-3.0.0-SNAPSHOT.jar
+wget https://repo.spring.io/snapshot/org/springframework/cloud/stream/app/http-request-processor-kafka/3.0.0-SNAPSHOT/http-request-processor-kafka-3.0.0-SNAPSHOT.jar
+```
+
+=== Start a Kafka message broker
+
+If you have Docker installed, you can start Kafka with
+```
+docker-compose up -f docker-compose-kafka.yml 
+```
+
+Or install and run Kafka on your local machine. 
+If you are using a remote Kafka cluster, set the property `--spring.cloud.stream.kafka.brokers=kafka_host1,...` to a comma-delimited list of host addresses on each of the following apps.
+
+=== Create input and output directories 
+Named `images` and `thumbnails` in this example.
+
+=== Start the sink
+Build the link:image-thumbnail-sink[], if you haven't already done it.
+Then open a terminal window in `image-thumbnail-sink` and run:
+
+```
+java -jar target/image-thumbnail-sink-0.0.1-SNAPSHOT.jar --file.consumer.directory=$(PWD)/thumbnails --spring.cloud.stream.bindings.input.destination=thumbnail --server.port=0
+```
+
+
+=== Start the source and processor
+
+In separate terminal sessions run the processor and the source:
+
+```
+java -jar http-request-processor-kafka-3.0.0-SNAPSHOT.jar --http.request.url-expression=payload --http.request.expected-response-type=byte[] --http.request.maximum-buffer-size=2097152 --spring.cloud.stream.bindings.input.destination=image --spring.cloud.stream.bindings.output.destination=thumbnail --spring.kafka.producer.properties.max.request.size=2097152 --server.port=0
+```
+
+```
+java -jar file-source-kafka-3.0.0-SNAPSHOT.jar --file.consumer.mode=lines --file.supplier.directory=$(PWD)/images --spring.cloud.stream.bindings.output.destination=image --server.port=0
+```
+[[Create_Some_Data]]
+=== Create some data
+
+Using your favorite text editor, create a file in the `images` directory containing some URLs:
+
+```
+https://i.imgur.com/FQtKSuv.jpeg
+https://i.imgur.com/4Cndaul.jpeg
+https://i.imgur.com/FCPLS42.jpeg
+https://i.imgur.com/DhzHsz8.jpg
+https://i.imgur.com/G7t1ZZl.jpg
+```
+
+You should see the thumbnail files in the `thumbnails` directory.
+
+image:../img/thumbnail-files.png[]

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/docker-compose-apps.yml

@@ -0,0 +1,45 @@
+version: '2'
+services:
+  kafka-broker:
+        environment:
+          - KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://kafka-broker:9092
+          - KAFKA_ADVERTISED_HOST_NAME=kafka-broker
+  source:
+    container_name: file-source
+    image: springcloudstream/file-source-kafka:3.0.0-SNAPSHOT
+    depends_on: 
+      - kafka-broker
+    environment: 
+      - FILE_SUPPLIER_DIRECTORY=/images
+      - FILE_CONSUMER_MODE=lines
+      - SPRING_CLOUD_STREAM_BINDINGS_OUTPUT_DESTINATION=image
+      - SPRING_CLOUD_STREAM_KAFKA_BINDER_BROKERS=kafka-broker
+    volumes:
+      - ./images:/images
+  processor:
+    container_name: http-request-processor
+    image: springcloudstream/http-request-processor-kafka:3.0.0-SNAPSHOT
+    depends_on: 
+      - kafka-broker
+    environment: 
+      - HTTP_REQUEST_URL_EXPRESSION=payload
+      - HTTP_REQUEST_EXPECTED_RESPONSE_TYPE=byte[]
+      - HTTP_REQUEST_MAXIMUM_BUFFER_SIZE=2097152
+      - SPRING_KAFKA_PRODUCER_PROPERTIES_MAX_REQUEST_SIZE=2097152
+      - SPRING_CLOUD_STREAM_BINDINGS_INPUT_DESTINATION=image
+      - SPRING_CLOUD_STREAM_BINDINGS_INPUT_GROUP=thumbnail
+      - SPRING_CLOUD_STREAM_BINDINGS_OUTPUT_DESTINATION=thumbnail
+      - SPRING_CLOUD_STREAM_KAFKA_BINDER_BROKERS=kafka-broker
+  sink:
+    container_name: image-thumbnail-sink
+    image: demo/image-thumbnail-sink
+    depends_on: 
+      - kafka-broker
+    environment: 
+      - SPRING_CLOUD_STREAM_KAFKA_BINDER_BROKERS=kafka-broker
+      - SPRING_CLOUD_STREAM_BINDINGS_INPUT_DESTINATION=thumbnail
+      - SPRING_CLOUD_STREAM_BINDINGS_INPUT_GROUP=thumbnail
+      - FILE_CONSUMER_DIRECTORY=/thumbnails
+    volumes:
+      - ./thumbnails:/thumbnails
+    

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/docker-compose-kafka.yml

@@ -0,0 +1,26 @@
+version: '2'
+services:
+  kafka-broker:
+    container_name: kafka-broker
+    image: confluentinc/cp-kafka:5.3.1
+    ports:
+      - "9092:9092"
+    environment:
+      - KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://127.0.0.1:9092
+      - KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181
+      - KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR=1
+      - KAFKA_MESSAGE_MAX_BYTES=2097152
+    depends_on:
+      - zookeeper
+
+  zookeeper:
+    container_name: zookeeper
+    image: confluentinc/cp-zookeeper:5.3.1
+    expose:
+      - "2181"
+    environment:
+      - ZOOKEEPER_CLIENT_PORT=2181
+    
+
+  
+    

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/README.adoc

@@ -0,0 +1,25 @@
+= Thumbnail Sink
+
+A Spring Cloud Stream Sink which composes thumbnailProcessor|filenameEnricher|fileConsumer to create thumbnails and write to a file.
+
+This app registers the link:../image-thumbnail-processor/src/main/java/io/spring/example/image/thumbnail/processor/ThumbnailProcessor.java[ThumbnailProcessor] as a Spring bean and uses the standard https://github.com/spring-cloud/stream-applications/tree/master/functions/consumer/file-consumer[fileConsumer] to write files.
+It implements a link:src/main/java/io/spring/example/image/thumbnail/sink/ThumbnailSinkApplication.java[filenameEnricher] function, which generates filenames as
+`thumbnail-%d.jpg`, incrementing the index on each execution, supplied to the fileConsumer in the `filename` message header.
+See Also link:src/main/resources/application.properties[application.properties].
+
+== Build
+
+```
+./mvnw clean install
+```
+
+or to build a Docker image 
+
+```
+./mvnw clean package jib:dockerBuild
+```
+
+
+
+
+

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/mvnw

@@ -0,0 +1,322 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ]; then
+
+  if [ -f /etc/mavenrc ]; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ]; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false
+darwin=false
+mingw=false
+case "$(uname)" in
+CYGWIN*) cygwin=true ;;
+MINGW*) mingw=true ;;
+Darwin*)
+  darwin=true
+  # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+  # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+  if [ -z "$JAVA_HOME" ]; then
+    if [ -x "/usr/libexec/java_home" ]; then
+      export JAVA_HOME="$(/usr/libexec/java_home)"
+    else
+      export JAVA_HOME="/Library/Java/Home"
+    fi
+  fi
+  ;;
+esac
+
+if [ -z "$JAVA_HOME" ]; then
+  if [ -r /etc/gentoo-release ]; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+if [ -z "$M2_HOME" ]; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ]; do
+    ls=$(ls -ld "$PRG")
+    link=$(expr "$ls" : '.*-> \(.*\)$')
+    if expr "$link" : '/.*' >/dev/null; then
+      PRG="$link"
+    else
+      PRG="$(dirname "$PRG")/$link"
+    fi
+  done
+
+  saveddir=$(pwd)
+
+  M2_HOME=$(dirname "$PRG")/..
+
+  # make it fully qualified
+  M2_HOME=$(cd "$M2_HOME" && pwd)
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --unix "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --unix "$CLASSPATH")
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="$( (
+      cd "$M2_HOME"
+      pwd
+    ))"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="$( (
+      cd "$JAVA_HOME"
+      pwd
+    ))"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="$(which javac)"
+  if [ -n "$javaExecutable" ] && ! [ "$(expr \"$javaExecutable\" : '\([^ ]*\)')" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=$(which readlink)
+    if [ ! $(expr "$readLink" : '\([^ ]*\)') = "no" ]; then
+      if $darwin; then
+        javaHome="$(dirname \"$javaExecutable\")"
+        javaExecutable="$(cd \"$javaHome\" && pwd -P)/javac"
+      else
+        javaExecutable="$(readlink -f \"$javaExecutable\")"
+      fi
+      javaHome="$(dirname \"$javaExecutable\")"
+      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ]; then
+  if [ -n "$JAVA_HOME" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="$(which java)"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ]; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]; then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ]; do
+    if [ -d "$wdir"/.mvn ]; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=$(
+        cd "$wdir/.."
+        pwd
+      )
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' <"$1")"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(pwd)")
+if [ -z "$BASE_DIR" ]; then
+  exit 1
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Found .mvn/wrapper/maven-wrapper.jar"
+  fi
+else
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+  fi
+  if [ -n "$MVNW_REPOURL" ]; then
+    jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  else
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  fi
+  while IFS="=" read key value; do
+    case "$key" in wrapperUrl)
+      jarUrl="$value"
+      break
+      ;;
+    esac
+  done <"$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Downloading from: $jarUrl"
+  fi
+  wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+  if $cygwin; then
+    wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+  fi
+
+  if command -v wget >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found wget ... using wget"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      wget "$jarUrl" -O "$wrapperJarPath"
+    else
+      wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+    fi
+  elif command -v curl >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found curl ... using curl"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      curl -o "$wrapperJarPath" "$jarUrl" -f
+    else
+      curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+    fi
+
+  else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Falling back to using Java to download"
+    fi
+    javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+    # For Cygwin, switch paths to Windows format before running javac
+    if $cygwin; then
+      javaClass=$(cygpath --path --windows "$javaClass")
+    fi
+    if [ -e "$javaClass" ]; then
+      if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Compiling MavenWrapperDownloader.java ..."
+        fi
+        # Compiling the Java class
+        ("$JAVA_HOME/bin/javac" "$javaClass")
+      fi
+      if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        # Running the downloader
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Running MavenWrapperDownloader.java ..."
+        fi
+        ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+      fi
+    fi
+  fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --path --windows "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --path --windows "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --windows "$CLASSPATH")
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=$(cygpath --path --windows "$MAVEN_PROJECTBASEDIR")
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/pom.xml

@@ -0,0 +1,154 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.4.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.spring.cloud.stream.sample</groupId>
+	<artifactId>image-thumbnail-sink</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>image-thumbnail-sink</name>
+	<description>Thumbnail Sink Application</description>
+	<properties>
+		<java.version>8</java.version>
+		<spring-cloud.version>Hoxton.SR8</spring-cloud.version>
+		<docker.org>demo</docker.org>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>io.spring.cloud.stream.sample</groupId>
+			<artifactId>image-thumbnail-processor</artifactId>
+			<version>0.0.1-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud.fn</groupId>
+			<artifactId>file-consumer</artifactId>
+			<version>1.0.0-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream-binder-kafka</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud.stream.app</groupId>
+			<artifactId>stream-applications-composite-function-support</artifactId>
+			<version>3.0.0-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream</artifactId>
+			<type>test-jar</type>
+			<classifier>test-binder</classifier>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>io.projectreactor</groupId>
+			<artifactId>reactor-test</artifactId>
+		</dependency>
+	</dependencies>
+	<dependencyManagement>
+		<dependencies>
+			<dependency>
+				<groupId>org.springframework.cloud</groupId>
+				<artifactId>spring-cloud-dependencies</artifactId>
+				<version>${spring-cloud.version}</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+			<plugin>
+				<groupId>com.google.cloud.tools</groupId>
+				<artifactId>jib-maven-plugin</artifactId>
+				<version>2.0.0</version>
+				<configuration>
+					<from>
+						<image>springcloud/openjdk</image>
+					</from>
+					<to>
+						<image>${docker.org}/${project.artifactId}</image>
+						<tags>
+							<tag>${project.version}</tag>
+						</tags>
+					</to>
+					<container>
+						<creationTime>USE_CURRENT_TIMESTAMP</creationTime>
+						<format>Docker</format>
+					</container>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+	<repositories>
+		<repository>
+			<id>spring-snapshots</id>
+			<name>Spring Snapshots</name>
+			<url>https://repo.spring.io/snapshot</url>
+			<snapshots>
+				<enabled>true</enabled>
+			</snapshots>
+			<releases>
+				<enabled>false</enabled>
+			</releases>
+		</repository>
+		<repository>
+			<id>spring-milestones</id>
+			<name>Spring Milestones</name>
+			<url>https://repo.spring.io/milestonl</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</repository>
+	</repositories>
+	<pluginRepositories>
+		<pluginRepository>
+			<id>spring-snapshots</id>
+			<name>Spring Snapshots</name>
+			<url>https://repo.spring.io/snapshot</url>
+			<snapshots>
+				<enabled>true</enabled>
+			</snapshots>
+			<releases>
+				<enabled>false</enabled>
+			</releases>
+		</pluginRepository>
+		<pluginRepository>
+			<id>spring-milestones</id>
+			<name>Spring Milestones</name>
+			<url>https://repo.spring.io/milestone</url>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</pluginRepository>
+	</pluginRepositories>
+</project>

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/src/main/java/io/spring/example/image/thumbnail/sink/ThumbnailSinkApplication.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.image.thumbnail.sink;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Function;
+
+import io.spring.example.image.thumbnail.processor.ThumbnailProcessor;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.fn.consumer.file.FileConsumerConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+
+@SpringBootApplication
+@Import(FileConsumerConfiguration.class)
+public class ThumbnailSinkApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(ThumbnailSinkApplication.class, args);
+	}
+
+	@Bean
+	public Function<?, Message<?>> filenameEnricher() {
+		AtomicInteger count = new AtomicInteger();
+		return payload -> MessageBuilder.withPayload(payload).setHeader("filename",
+				String.format("thumbnail-%d.jpg", count.incrementAndGet())).build();
+	}
+
+	@Bean
+	ThumbnailProcessor thumbnailProcessor() {
+		return new ThumbnailProcessor();
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/src/main/resources/application.properties

@@ -0,0 +1,6 @@
+file.consumer.binary=true
+file.consumer.mode=replace
+file.consumer.name-expression=headers[filename]
+spring.cloud.function.definition=thumbnailProcessor|filenameEnricher|fileConsumer
+
+

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/src/test/java/io/spring/example/image/thumbnail/sink/ThumbnailSinkIntegrationTests.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.image.thumbnail.sink;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Properties;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.cloud.stream.binder.test.InputDestination;
+import org.springframework.cloud.stream.binder.test.TestChannelBinderConfiguration;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.Resource;
+import org.springframework.messaging.support.MessageBuilder;
+
+import static org.awaitility.Awaitility.await;
+
+public class ThumbnailSinkIntegrationTests {
+
+	@TempDir
+	File tempDir;
+
+	@Test
+	void test() throws IOException {
+		byte[] data = readAllBytes(new ClassPathResource("firetruck.jpg"));
+		TestChannelBinderConfiguration.applicationContextRunner(ThumbnailSinkApplication.class)
+				.withPropertyValues(applicationProperties())
+				.withPropertyValues(
+						"file.consumer.directory=" + tempDir.getAbsolutePath())
+				.run(context -> {
+					InputDestination inputDestination = context.getBean(InputDestination.class);
+					inputDestination.send(MessageBuilder.withPayload(data).build());
+				});
+		await().timeout(Duration.ofSeconds(10))
+				.until(() -> Files.exists(Paths.get(tempDir.getAbsolutePath(), "thumbnail-1.jpg")));
+	}
+
+	private byte[] readAllBytes(Resource resource) throws IOException {
+		InputStream is = resource.getInputStream();
+		byte[] bytes = new byte[is.available()];
+		is.read(bytes);
+		return bytes;
+	}
+
+	private String[] applicationProperties() throws IOException {
+		Properties properties = new Properties();
+		properties.load(new ClassPathResource("application.properties").getInputStream());
+		ArrayList<String> props = new ArrayList(properties.size());
+		properties.forEach((k, v) -> props.add(String.format("%s=%s", k.toString(), v.toString())));
+		return props.toArray(new String[properties.size()]);
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/image-thumbnail-sink/src/test/resources/logback.xml

@@ -0,0 +1,14 @@
+<configuration>
+
+	<appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+		<layout class="ch.qos.logback.classic.PatternLayout">
+			<Pattern>
+				%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n
+			</Pattern>
+		</layout>
+	</appender>
+	<root level="info">
+		<appender-ref ref="CONSOLE"/>
+	</root>
+
+</configuration>

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-stream-sample/images.txt

@@ -0,0 +1,5 @@
+https://i.imgur.com/FQtKSuv.jpeg
+https://i.imgur.com/4Cndaul.jpeg
+https://i.imgur.com/FCPLS42.jpeg
+https://i.imgur.com/DhzHsz8.jpg
+https://i.imgur.com/G7t1ZZl.jpg

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/README.adoc

@@ -0,0 +1,21 @@
+= Thumbnail Standalone
+
+This demonstrates the use of the Spring https://github.com/spring-cloud/stream-applications/blob/master/functions/function/http-request-function[HttpRequestFunction]
+in a standalone Spring Boot Application
+
+This web app downloads an image from the web and uses the link:../image-thumbnail-processor/src/main/java/io/spring/example/image/thumbnail/processor/ThumbnailProcessor.java[ThumbnailProcessor] to create a thumbnail of it.
+
+== Run
+
+```bash
+./mvnw spring-boot:run
+```
+
+== Try some cat pics!
+
+* http://localhost:8080/thumbnail?url=https://i.imgur.com/FQtKSuv.jpeg
+* http://localhost:8080/thumbnail?url=https://i.imgur.com/4Cndaul.jpeg
+* http://localhost:8080/thumbnail?url=https://i.imgur.com/FCPLS42.jpeg
+* http://localhost:8080/thumbnail?url=https://i.imgur.com/DhzHsz8.jpg
+* http://localhost:8080/thumbnail?url=https://i.imgur.com/G7t1ZZl.jpg
+* http://localhost:8080/thumbnail?url=https://cdn.freeyork.org/wp-content/uploads/2017/11/handicapped-cat-rexie-fy-4-1152x1152.jpg

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/mvnw

@@ -0,0 +1,322 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ]; then
+
+  if [ -f /etc/mavenrc ]; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ]; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false
+darwin=false
+mingw=false
+case "$(uname)" in
+CYGWIN*) cygwin=true ;;
+MINGW*) mingw=true ;;
+Darwin*)
+  darwin=true
+  # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+  # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+  if [ -z "$JAVA_HOME" ]; then
+    if [ -x "/usr/libexec/java_home" ]; then
+      export JAVA_HOME="$(/usr/libexec/java_home)"
+    else
+      export JAVA_HOME="/Library/Java/Home"
+    fi
+  fi
+  ;;
+esac
+
+if [ -z "$JAVA_HOME" ]; then
+  if [ -r /etc/gentoo-release ]; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+if [ -z "$M2_HOME" ]; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ]; do
+    ls=$(ls -ld "$PRG")
+    link=$(expr "$ls" : '.*-> \(.*\)$')
+    if expr "$link" : '/.*' >/dev/null; then
+      PRG="$link"
+    else
+      PRG="$(dirname "$PRG")/$link"
+    fi
+  done
+
+  saveddir=$(pwd)
+
+  M2_HOME=$(dirname "$PRG")/..
+
+  # make it fully qualified
+  M2_HOME=$(cd "$M2_HOME" && pwd)
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --unix "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --unix "$CLASSPATH")
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="$( (
+      cd "$M2_HOME"
+      pwd
+    ))"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="$( (
+      cd "$JAVA_HOME"
+      pwd
+    ))"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="$(which javac)"
+  if [ -n "$javaExecutable" ] && ! [ "$(expr \"$javaExecutable\" : '\([^ ]*\)')" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=$(which readlink)
+    if [ ! $(expr "$readLink" : '\([^ ]*\)') = "no" ]; then
+      if $darwin; then
+        javaHome="$(dirname \"$javaExecutable\")"
+        javaExecutable="$(cd \"$javaHome\" && pwd -P)/javac"
+      else
+        javaExecutable="$(readlink -f \"$javaExecutable\")"
+      fi
+      javaHome="$(dirname \"$javaExecutable\")"
+      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ]; then
+  if [ -n "$JAVA_HOME" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="$(which java)"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ]; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]; then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ]; do
+    if [ -d "$wdir"/.mvn ]; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=$(
+        cd "$wdir/.."
+        pwd
+      )
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' <"$1")"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(pwd)")
+if [ -z "$BASE_DIR" ]; then
+  exit 1
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Found .mvn/wrapper/maven-wrapper.jar"
+  fi
+else
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+  fi
+  if [ -n "$MVNW_REPOURL" ]; then
+    jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  else
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  fi
+  while IFS="=" read key value; do
+    case "$key" in wrapperUrl)
+      jarUrl="$value"
+      break
+      ;;
+    esac
+  done <"$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Downloading from: $jarUrl"
+  fi
+  wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+  if $cygwin; then
+    wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+  fi
+
+  if command -v wget >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found wget ... using wget"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      wget "$jarUrl" -O "$wrapperJarPath"
+    else
+      wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+    fi
+  elif command -v curl >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found curl ... using curl"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      curl -o "$wrapperJarPath" "$jarUrl" -f
+    else
+      curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+    fi
+
+  else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Falling back to using Java to download"
+    fi
+    javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+    # For Cygwin, switch paths to Windows format before running javac
+    if $cygwin; then
+      javaClass=$(cygpath --path --windows "$javaClass")
+    fi
+    if [ -e "$javaClass" ]; then
+      if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Compiling MavenWrapperDownloader.java ..."
+        fi
+        # Compiling the Java class
+        ("$JAVA_HOME/bin/javac" "$javaClass")
+      fi
+      if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        # Running the downloader
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Running MavenWrapperDownloader.java ..."
+        fi
+        ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+      fi
+    fi
+  fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --path --windows "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --path --windows "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --windows "$CLASSPATH")
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=$(cygpath --path --windows "$MAVEN_PROJECTBASEDIR")
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/pom.xml

@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.4.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>io.spring.cloud.stream.sample</groupId>
+	<artifactId>image-thumbnail-web</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>image-thumbnail-web</name>
+	<description>Demo project for Spring Boot</description>
+
+	<properties>
+		<java.version>8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.cloud.fn</groupId>
+			<artifactId>http-request-function</artifactId>
+			<version>1.0.0-SNAPSHOT</version>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-thymeleaf</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-devtools</artifactId>
+			<scope>runtime</scope>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>io.spring.cloud.stream.sample</groupId>
+			<artifactId>image-thumbnail-processor</artifactId>
+			<version>0.0.1-SNAPSHOT</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/java/io/spring/example/image/thumbnail/standalone/ThumbnailStandaloneApplication.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2020-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.example.image.thumbnail.standalone;
+
+import java.util.Base64;
+import java.util.HashMap;
+import java.util.Map;
+
+import io.spring.example.image.thumbnail.processor.ThumbnailProcessor;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.fn.http.request.HttpRequestFunctionConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.messaging.support.GenericMessage;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+
+import static org.springframework.cloud.fn.http.request.HttpRequestFunctionConfiguration.HttpRequestFunction;
+
+@SpringBootApplication
+@Controller
+@Import(HttpRequestFunctionConfiguration.class)
+public class ThumbnailStandaloneApplication {
+	private static Logger logger = LoggerFactory.getLogger(ThumbnailStandaloneApplication.class);
+
+	public static void main(String[] args) {
+		SpringApplication.run(ThumbnailStandaloneApplication.class, args);
+	}
+
+	private ThumbnailProcessor thumbnailProcessor = new ThumbnailProcessor();
+
+	@Autowired
+	private HttpRequestFunction httpRequestFunction;
+
+	@Bean
+	RouterFunction<?> routes() {
+		return RouterFunctions.route()
+				.GET("/thumbnail", this::createThumbnail)
+				.build();
+	}
+
+	private Mono<ServerResponse> createThumbnail(ServerRequest serverRequest) {
+		String url = serverRequest.queryParam("url").orElseThrow(() -> new RuntimeException("URL required"));
+
+		return Mono.from(httpRequestFunction.apply(Flux.just(new GenericMessage<>(url)))
+				.flatMap(image -> {
+					Map<String, Object> model = new HashMap<>();
+					byte[] thumbnail = thumbnailProcessor.apply((byte[]) image);
+					logger.info("creating thumbnail for {}", url);
+					model.put("url", url);
+					model.put("thumb", new String(Base64.getEncoder().encode(thumbnail)));
+					Mono<ServerResponse> serverResponse = ServerResponse.ok()
+							.render("thumbnail", model);
+					return serverResponse;
+				}));
+	}
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/application.properties

@@ -0,0 +1,4 @@
+http.request.url-expression=payload
+http.request.expected-response-type=byte[]
+http.request.maximum-buffer-size=2097152
+

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/static/styles/thumbnail.css

@@ -0,0 +1,14 @@
+body {
+    background-color: black;
+}
+h1 {
+    color: palegreen;
+}
+
+img {
+    padding: 10px;
+    border: 2px solid white;
+    display: inline-block;
+    vertical-align: top;
+    max-width: 75%;
+}

function-based-stream-app-samples/image-thumbnail-samples/image-thumbnail-web/src/main/resources/templates/thumbnail.html

@@ -0,0 +1,15 @@
+<!DOCTYPE HTML>
+<html xmlns:th="http://www.thymeleaf.org">
+<head>
+    <title>Getting Started: Serving Web Content</title>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
+    <link th:href="@{/styles/thumbnail.css}" rel="stylesheet">
+</head>
+<body>
+<h1 th:text="'Thumbnail for ' + ${url}"/>
+<div class="images">
+    <img id="full" th:src="${url}"/>
+    <img th:src="'data:image/gif;base64,' + ${thumb}" , alt="thumbnail image"/>
+</div>
+</body>
+</html>

function-based-stream-app-samples/image-thumbnail-samples/mvnw

@@ -0,0 +1,322 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ]; then
+
+  if [ -f /etc/mavenrc ]; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ]; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false
+darwin=false
+mingw=false
+case "$(uname)" in
+CYGWIN*) cygwin=true ;;
+MINGW*) mingw=true ;;
+Darwin*)
+  darwin=true
+  # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+  # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+  if [ -z "$JAVA_HOME" ]; then
+    if [ -x "/usr/libexec/java_home" ]; then
+      export JAVA_HOME="$(/usr/libexec/java_home)"
+    else
+      export JAVA_HOME="/Library/Java/Home"
+    fi
+  fi
+  ;;
+esac
+
+if [ -z "$JAVA_HOME" ]; then
+  if [ -r /etc/gentoo-release ]; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+if [ -z "$M2_HOME" ]; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ]; do
+    ls=$(ls -ld "$PRG")
+    link=$(expr "$ls" : '.*-> \(.*\)$')
+    if expr "$link" : '/.*' >/dev/null; then
+      PRG="$link"
+    else
+      PRG="$(dirname "$PRG")/$link"
+    fi
+  done
+
+  saveddir=$(pwd)
+
+  M2_HOME=$(dirname "$PRG")/..
+
+  # make it fully qualified
+  M2_HOME=$(cd "$M2_HOME" && pwd)
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --unix "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --unix "$CLASSPATH")
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="$( (
+      cd "$M2_HOME"
+      pwd
+    ))"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="$( (
+      cd "$JAVA_HOME"
+      pwd
+    ))"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="$(which javac)"
+  if [ -n "$javaExecutable" ] && ! [ "$(expr \"$javaExecutable\" : '\([^ ]*\)')" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=$(which readlink)
+    if [ ! $(expr "$readLink" : '\([^ ]*\)') = "no" ]; then
+      if $darwin; then
+        javaHome="$(dirname \"$javaExecutable\")"
+        javaExecutable="$(cd \"$javaHome\" && pwd -P)/javac"
+      else
+        javaExecutable="$(readlink -f \"$javaExecutable\")"
+      fi
+      javaHome="$(dirname \"$javaExecutable\")"
+      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ]; then
+  if [ -n "$JAVA_HOME" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="$(which java)"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ]; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]; then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ]; do
+    if [ -d "$wdir"/.mvn ]; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=$(
+        cd "$wdir/.."
+        pwd
+      )
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' <"$1")"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(pwd)")
+if [ -z "$BASE_DIR" ]; then
+  exit 1
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Found .mvn/wrapper/maven-wrapper.jar"
+  fi
+else
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+  fi
+  if [ -n "$MVNW_REPOURL" ]; then
+    jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  else
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  fi
+  while IFS="=" read key value; do
+    case "$key" in wrapperUrl)
+      jarUrl="$value"
+      break
+      ;;
+    esac
+  done <"$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Downloading from: $jarUrl"
+  fi
+  wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+  if $cygwin; then
+    wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+  fi
+
+  if command -v wget >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found wget ... using wget"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      wget "$jarUrl" -O "$wrapperJarPath"
+    else
+      wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+    fi
+  elif command -v curl >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found curl ... using curl"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      curl -o "$wrapperJarPath" "$jarUrl" -f
+    else
+      curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+    fi
+
+  else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Falling back to using Java to download"
+    fi
+    javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+    # For Cygwin, switch paths to Windows format before running javac
+    if $cygwin; then
+      javaClass=$(cygpath --path --windows "$javaClass")
+    fi
+    if [ -e "$javaClass" ]; then
+      if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Compiling MavenWrapperDownloader.java ..."
+        fi
+        # Compiling the Java class
+        ("$JAVA_HOME/bin/javac" "$javaClass")
+      fi
+      if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        # Running the downloader
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Running MavenWrapperDownloader.java ..."
+        fi
+        ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+      fi
+    fi
+  fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --path --windows "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --path --windows "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --windows "$CLASSPATH")
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=$(cygpath --path --windows "$MAVEN_PROJECTBASEDIR")
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/image-thumbnail-samples/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/image-thumbnail-samples/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>io.spring.cloud.stream.sample</groupId>
+	<artifactId>image-thumbnail-samples</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>image-thumbnail-samples</name>
+	<description>Samples using HTTP Request Function</description>
+	<packaging>pom</packaging>
+
+	<properties>
+		<java.version>8</java.version>
+	</properties>
+
+	<modules>
+		<module>image-thumbnail-web</module>
+		<module>image-thumbnail-stream-sample/image-thumbnail-sink</module>
+		<module>image-thumbnail-processor</module>
+	</modules>
+
+</project>

function-based-stream-app-samples/mvnw

@@ -0,0 +1,322 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ]; then
+
+  if [ -f /etc/mavenrc ]; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ]; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false
+darwin=false
+mingw=false
+case "$(uname)" in
+CYGWIN*) cygwin=true ;;
+MINGW*) mingw=true ;;
+Darwin*)
+  darwin=true
+  # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+  # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+  if [ -z "$JAVA_HOME" ]; then
+    if [ -x "/usr/libexec/java_home" ]; then
+      export JAVA_HOME="$(/usr/libexec/java_home)"
+    else
+      export JAVA_HOME="/Library/Java/Home"
+    fi
+  fi
+  ;;
+esac
+
+if [ -z "$JAVA_HOME" ]; then
+  if [ -r /etc/gentoo-release ]; then
+    JAVA_HOME=$(java-config --jre-home)
+  fi
+fi
+
+if [ -z "$M2_HOME" ]; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ]; do
+    ls=$(ls -ld "$PRG")
+    link=$(expr "$ls" : '.*-> \(.*\)$')
+    if expr "$link" : '/.*' >/dev/null; then
+      PRG="$link"
+    else
+      PRG="$(dirname "$PRG")/$link"
+    fi
+  done
+
+  saveddir=$(pwd)
+
+  M2_HOME=$(dirname "$PRG")/..
+
+  # make it fully qualified
+  M2_HOME=$(cd "$M2_HOME" && pwd)
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --unix "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --unix "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --unix "$CLASSPATH")
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="$( (
+      cd "$M2_HOME"
+      pwd
+    ))"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="$( (
+      cd "$JAVA_HOME"
+      pwd
+    ))"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="$(which javac)"
+  if [ -n "$javaExecutable" ] && ! [ "$(expr \"$javaExecutable\" : '\([^ ]*\)')" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=$(which readlink)
+    if [ ! $(expr "$readLink" : '\([^ ]*\)') = "no" ]; then
+      if $darwin; then
+        javaHome="$(dirname \"$javaExecutable\")"
+        javaExecutable="$(cd \"$javaHome\" && pwd -P)/javac"
+      else
+        javaExecutable="$(readlink -f \"$javaExecutable\")"
+      fi
+      javaHome="$(dirname \"$javaExecutable\")"
+      javaHome=$(expr "$javaHome" : '\(.*\)/bin')
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ]; then
+  if [ -n "$JAVA_HOME" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="$(which java)"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ]; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]; then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ]; do
+    if [ -d "$wdir"/.mvn ]; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=$(
+        cd "$wdir/.."
+        pwd
+      )
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' <"$1")"
+  fi
+}
+
+BASE_DIR=$(find_maven_basedir "$(pwd)")
+if [ -z "$BASE_DIR" ]; then
+  exit 1
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Found .mvn/wrapper/maven-wrapper.jar"
+  fi
+else
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+  fi
+  if [ -n "$MVNW_REPOURL" ]; then
+    jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  else
+    jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+  fi
+  while IFS="=" read key value; do
+    case "$key" in wrapperUrl)
+      jarUrl="$value"
+      break
+      ;;
+    esac
+  done <"$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+  if [ "$MVNW_VERBOSE" = true ]; then
+    echo "Downloading from: $jarUrl"
+  fi
+  wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+  if $cygwin; then
+    wrapperJarPath=$(cygpath --path --windows "$wrapperJarPath")
+  fi
+
+  if command -v wget >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found wget ... using wget"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      wget "$jarUrl" -O "$wrapperJarPath"
+    else
+      wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+    fi
+  elif command -v curl >/dev/null; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found curl ... using curl"
+    fi
+    if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+      curl -o "$wrapperJarPath" "$jarUrl" -f
+    else
+      curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+    fi
+
+  else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Falling back to using Java to download"
+    fi
+    javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+    # For Cygwin, switch paths to Windows format before running javac
+    if $cygwin; then
+      javaClass=$(cygpath --path --windows "$javaClass")
+    fi
+    if [ -e "$javaClass" ]; then
+      if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Compiling MavenWrapperDownloader.java ..."
+        fi
+        # Compiling the Java class
+        ("$JAVA_HOME/bin/javac" "$javaClass")
+      fi
+      if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+        # Running the downloader
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo " - Running MavenWrapperDownloader.java ..."
+        fi
+        ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+      fi
+    fi
+  fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=$(cygpath --path --windows "$M2_HOME")
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=$(cygpath --path --windows "$JAVA_HOME")
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=$(cygpath --path --windows "$CLASSPATH")
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=$(cygpath --path --windows "$MAVEN_PROJECTBASEDIR")
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

function-based-stream-app-samples/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

function-based-stream-app-samples/pom.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>io.spring.cloud.stream.sample</groupId>
+	<artifactId>function-based-stream-app-samples</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>function-based-stream-app-samples</name>
+	<description>Samples using Functions and Function-based stream applications</description>
+	<packaging>pom</packaging>
+
+	<properties>
+		<java.version>8</java.version>
+	</properties>
+
+	<modules>
+		<module>image-thumbnail-samples</module>
+		<module>couchbase-stream-applications</module>
+	</modules>
+
+</project>

kafka-batch-sample/.gitignore

@@ -0,0 +1,33 @@
+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

kafka-batch-sample/.mvn/wrapper/MavenWrapperDownloader.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

kafka-batch-sample/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

kafka-batch-sample/README.adoc

@@ -0,0 +1,25 @@
+== What is this app?
+
+This is an example of a Spring Cloud Stream demonstrating the processing of record batches.
+
+The application simply upper-cases the input records and sends them to another topic.
+
+=== Running the app:
+
+Go to the root of the repository and do:
+
+`docker-compose up -d` (if you don't already have a Kafka broker running locally).
+
+`./mvnw clean package`
+
+`java -jar target/kafka-batch-sample-0.0.1-SNAPSHOT.jar `
+
+There is a simple `@KafkaListener` method to display the records sent to the output topic.
+
+When run with `java -jar target/kafka-batch-sample-0.0.1-SNAPSHOT.jar --spring.profiles.active=transactional` the listener will suspend with
+
+`Hit Enter to exit the listener and commit transaction`.
+
+Pressing the enter key allows the listener to exit and the transaction will commit.
+
+Only then will you see the output from the `@KafkaListener` because its consumer is configured with `isolation.level: read_committed`.

kafka-batch-sample/docker-compose.yml

@@ -0,0 +1,18 @@
+version: '3'
+services:
+    kafka:
+      image: wurstmeister/kafka
+      ports:
+        - "9092:9092"
+      environment:
+        - KAFKA_ADVERTISED_HOST_NAME=127.0.0.1
+        - KAFKA_ADVERTISED_PORT=9092
+        - KAFKA_ZOOKEEPER_CONNECT=zookeeper:2181
+      depends_on:
+        - zookeeper
+    zookeeper:
+      image: wurstmeister/zookeeper
+      ports:
+        - "2181:2181"
+      environment:
+        - KAFKA_ADVERTISED_HOST_NAME=zookeeper

kafka-batch-sample/mvnw

@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+#   JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+#   M2_HOME - location of maven2's installed home dir
+#   MAVEN_OPTS - parameters passed to the Java VM when running Maven
+#     e.g. to debug Maven itself, use
+#       set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+#   MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+  if [ -f /etc/mavenrc ] ; then
+    . /etc/mavenrc
+  fi
+
+  if [ -f "$HOME/.mavenrc" ] ; then
+    . "$HOME/.mavenrc"
+  fi
+
+fi
+
+# OS specific support.  $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+  CYGWIN*) cygwin=true ;;
+  MINGW*) mingw=true;;
+  Darwin*) darwin=true
+    # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+    # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+    if [ -z "$JAVA_HOME" ]; then
+      if [ -x "/usr/libexec/java_home" ]; then
+        export JAVA_HOME="`/usr/libexec/java_home`"
+      else
+        export JAVA_HOME="/Library/Java/Home"
+      fi
+    fi
+    ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+  if [ -r /etc/gentoo-release ] ; then
+    JAVA_HOME=`java-config --jre-home`
+  fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+  ## resolve links - $0 may be a link to maven's home
+  PRG="$0"
+
+  # need this for relative symlinks
+  while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+      PRG="$link"
+    else
+      PRG="`dirname "$PRG"`/$link"
+    fi
+  done
+
+  saveddir=`pwd`
+
+  M2_HOME=`dirname "$PRG"`/..
+
+  # make it fully qualified
+  M2_HOME=`cd "$M2_HOME" && pwd`
+
+  cd "$saveddir"
+  # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --unix "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME="`(cd "$M2_HOME"; pwd)`"
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+  javaExecutable="`which javac`"
+  if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+    # readlink(1) is not available as standard on Solaris 10.
+    readLink=`which readlink`
+    if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+      if $darwin ; then
+        javaHome="`dirname \"$javaExecutable\"`"
+        javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+      else
+        javaExecutable="`readlink -f \"$javaExecutable\"`"
+      fi
+      javaHome="`dirname \"$javaExecutable\"`"
+      javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+      JAVA_HOME="$javaHome"
+      export JAVA_HOME
+    fi
+  fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+  if [ -n "$JAVA_HOME"  ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+    fi
+  else
+    JAVACMD="`which java`"
+  fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+  echo "Error: JAVA_HOME is not defined correctly." >&2
+  echo "  We cannot execute $JAVACMD" >&2
+  exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+  echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+  if [ -z "$1" ]
+  then
+    echo "Path not specified to find_maven_basedir"
+    return 1
+  fi
+
+  basedir="$1"
+  wdir="$1"
+  while [ "$wdir" != '/' ] ; do
+    if [ -d "$wdir"/.mvn ] ; then
+      basedir=$wdir
+      break
+    fi
+    # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+    if [ -d "${wdir}" ]; then
+      wdir=`cd "$wdir/.."; pwd`
+    fi
+    # end of workaround
+  done
+  echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+  if [ -f "$1" ]; then
+    echo "$(tr -s '\n' ' ' < "$1")"
+  fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+  exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Found .mvn/wrapper/maven-wrapper.jar"
+    fi
+else
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+    fi
+    if [ -n "$MVNW_REPOURL" ]; then
+      jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    else
+      jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    fi
+    while IFS="=" read key value; do
+      case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+      esac
+    done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+    if [ "$MVNW_VERBOSE" = true ]; then
+      echo "Downloading from: $jarUrl"
+    fi
+    wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+    if $cygwin; then
+      wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+    fi
+
+    if command -v wget > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found wget ... using wget"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            wget "$jarUrl" -O "$wrapperJarPath"
+        else
+            wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+        fi
+    elif command -v curl > /dev/null; then
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Found curl ... using curl"
+        fi
+        if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+            curl -o "$wrapperJarPath" "$jarUrl" -f
+        else
+            curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+        fi
+
+    else
+        if [ "$MVNW_VERBOSE" = true ]; then
+          echo "Falling back to using Java to download"
+        fi
+        javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+        # For Cygwin, switch paths to Windows format before running javac
+        if $cygwin; then
+          javaClass=`cygpath --path --windows "$javaClass"`
+        fi
+        if [ -e "$javaClass" ]; then
+            if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Compiling MavenWrapperDownloader.java ..."
+                fi
+                # Compiling the Java class
+                ("$JAVA_HOME/bin/javac" "$javaClass")
+            fi
+            if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+                # Running the downloader
+                if [ "$MVNW_VERBOSE" = true ]; then
+                  echo " - Running MavenWrapperDownloader.java ..."
+                fi
+                ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+            fi
+        fi
+    fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+  echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+  [ -n "$M2_HOME" ] &&
+    M2_HOME=`cygpath --path --windows "$M2_HOME"`
+  [ -n "$JAVA_HOME" ] &&
+    JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+  [ -n "$CLASSPATH" ] &&
+    CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+  [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+    MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+  $MAVEN_OPTS \
+  -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+  "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+  ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"

kafka-batch-sample/mvnw.cmd

@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

kafka-batch-sample/pom.xml

@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.3.3.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.example</groupId>
+	<artifactId>kafka-batch-sample</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>kafka-batch-sample</name>
+	<description>Demo project for Spring Boot</description>
+
+	<properties>
+		<java.version>1.8</java.version>
+		<spring-cloud.version>Hoxton.SR8</spring-cloud.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream-binder-kafka</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-stream-test-support</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.kafka</groupId>
+			<artifactId>spring-kafka-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<dependencyManagement>
+		<dependencies>
+			<dependency>
+				<groupId>org.springframework.cloud</groupId>
+				<artifactId>spring-cloud-dependencies</artifactId>
+				<version>${spring-cloud.version}</version>
+				<type>pom</type>
+				<scope>import</scope>
+			</dependency>
+		</dependencies>
+	</dependencyManagement>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

kafka-batch-sample/src/main/java/com/example/demo/KafkaBatchSampleApplication.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.demo;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.stream.IntStream;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.ApplicationRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.stream.function.StreamBridge;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Profile;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.stereotype.Component;
+
+@SpringBootApplication
+public class KafkaBatchSampleApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(KafkaBatchSampleApplication.class, args);
+	}
+
+	@KafkaListener(id = "batch-out", topics = "batch-out")
+	public void listen(String in) {
+		System.out.println(in);
+	}
+
+	@Bean
+	public ApplicationRunner runner(KafkaTemplate<byte[], byte[]> template) {
+		return args -> IntStream.range(0, 10).forEach(i -> template.send("batch-in", ("\"test" + i + "\"").getBytes()));
+	}
+
+}
+
+class Base {
+
+	@Autowired
+	StreamBridge bridge;
+
+}
+
+@Component
+@Profile("default")
+class NoTransactions extends Base {
+
+	@Bean
+	Consumer<List<String>> consumer() {
+		return list -> list.forEach(str -> bridge.send("output-out-0", str.toUpperCase()));
+	}
+
+}
+
+@Component
+@Profile("transactional")
+class Transactions extends Base {
+
+	@Bean
+	Consumer<List<String>> consumer() {
+		return list -> {
+			list.forEach(str -> bridge.send("output-out-0", str.toUpperCase()));
+			System.out.println("Hit Enter to exit the listener and commit transaction");
+			try {
+				System.in.read();
+			}
+			catch (IOException e) {
+				throw new UncheckedIOException(e);
+			}
+		};
+	}
+
+}

kafka-batch-sample/src/main/resources/application.yml

@@ -0,0 +1,30 @@
+spring:
+  cloud:
+    stream:
+      bindings:
+        consumer-in-0:
+          destination: batch-in
+          group: batch-in
+          consumer:
+            batch-mode: true
+        output-out-0:
+          destination: batch-out
+  kafka:
+    producer:
+      acks: all
+    consumer:
+      auto-offset-reset: earliest
+---
+
+spring:
+  profiles: transactional
+  kafka:
+    consumer:
+      properties:
+        isolation.level: read_committed
+  cloud:
+    stream:
+      kafka:
+        binder:
+          transaction:
+            transaction-id-prefix: batch-tx-

kafka-batch-sample/src/test/java/com/example/demo/KafkaBatchSampleApplicationTests.java

@@ -0,0 +1,13 @@
+package com.example.demo;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class KafkaBatchSampleApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}

kafka-e2e-kotlin-sample/.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1 @@
+distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.5.0/apache-maven-3.5.0-bin.zip

kafka-e2e-kotlin-sample/README.adoc

@@ -0,0 +1,97 @@
+== What is this app?
+
+This is an example using Spring Cloud Stream to model a subset of a purchasing system. This e2e project showcases the following
+features:
+
+* Avro messaging
+* Confluent Schema Registry
+* Event-carried state transfer pattern
+* KStream processing with a join operation
+
+=== Running the app:
+
+Start the Confluent Platform:
+
+```
+git clone https://github.com/confluentinc/cp-docker-images
+cd cp-docker-images
+git checkout 5.2.1-post
+cd examples/cp-all-in-one/
+docker-compose up -d --build
+```
+
+Go to the root of the sample project and do:
+
+`./mvnw clean package`
+
+`java -jar customer-service/target/customer-service-0.0.1-SNAPSHOT.jar`
+
+`java -jar order-service/target/order-service-0.0.1-SNAPSHOT.jar`
+
+`java -jar shipping-service/target/shipping-service-0.0.1-SNAPSHOT.jar`
+
+
+Start two https://github.com/edenhill/kafkacat[kafkacat] processes to examine topic information:
+
+```
+kafkacat -b localhost:9092 -t customer -C \
+  -f '\nKey (%K bytes): %k
+  Value (%S bytes): %s
+  Timestamp: %T
+  Partition: %p
+  Offset: %o
+  Headers: %h\n'
+```
+
+
+```
+kafkacat -b localhost:9092 -t order -C \
+  -f '\nKey (%K bytes): %k
+  Value (%S bytes): %s
+  Timestamp: %T
+  Partition: %p
+  Offset: %o
+  Headers: %h\n'
+```
+
+Create a customer:
+
+`curl -X POST -H "content-type: application/json" http://localhost:8084/customers -d '{"id":1,"name":"John Doe","address":"Elm Street"}'`
+
+Create an order for that customer:
+
+`curl -X POST http://localhost:8085/orders -H "content-type: application/json" -d '{"id":1,"productId":100,"customerId":1}'`
+
+Check the kafkacat output to verify that there is a record in the customer topic, and two in the order topic, corresponding
+to the OrderCreatedEvent from customer-service and the OrderShippedEvent from shipping-service.
+
+Customer topic kafkacat output:
+
+```
+Key (4 bytes):
+  Value (26 bytes): John DoeElm Street
+  Timestamp: 1561153134430
+  Partition: 0
+  Offset: 0
+  Headers:
+
+```
+
+Order topic kafkacat output:
+
+```
+Key (4 bytes):
+  Value (9 bytes): ?
+  Timestamp: 1561153313512
+  Partition: 0
+  Offset: 0
+  Headers:
+
+Key (4 bytes):
+  Value (28 bytes): ?John DoeElm Street
+  Timestamp: 1561153313512
+  Partition: 0
+  Offset: 1
+  Headers:
+
+```

kafka-e2e-kotlin-sample/customer-service/.gitignore

@@ -0,0 +1,24 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+nbproject/private/
+build/
+nbbuild/
+dist/
+nbdist/
+.nb-gradle/

kafka-e2e-kotlin-sample/customer-service/pom.xml

@@ -0,0 +1,198 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>customer-service</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>customer-service</name>
+    <description>Customer Service</description>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.3.4.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <properties>
+        <java.version>1.8</java.version>
+        <kotlin.version>1.3.31</kotlin.version>
+        <avro.version>1.8.2</avro.version>
+        <confluent.version>5.2.1</confluent.version>
+        <spring-cloud.version>Hoxton.BUILD-SNAPSHOT</spring-cloud.version>
+    </properties>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.cloud</groupId>
+                <artifactId>spring-cloud-dependencies</artifactId>
+                <version>${spring-cloud.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.confluent</groupId>
+            <artifactId>kafka-streams-avro-serde</artifactId>
+            <version>${confluent.version}</version>
+            <exclusions>
+                <exclusion>
+                    <groupId>org.slf4j</groupId>
+                    <artifactId>slf4j-log4j12</artifactId>
+                </exclusion>
+            </exclusions>
+        </dependency>
+        <dependency>
+            <groupId>io.confluent</groupId>
+            <artifactId>kafka-avro-serializer</artifactId>
+            <version>${confluent.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>io.confluent</groupId>
+            <artifactId>kafka-schema-registry-client</artifactId>
+            <version>${confluent.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.avro</groupId>
+            <artifactId>avro</artifactId>
+            <version>${avro.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-stream-kafka</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-stream-schema</artifactId>
+            <version>3.0.0.BUILD-SNAPSHOT</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.module</groupId>
+            <artifactId>jackson-module-kotlin</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-reflect</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib-jdk8</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-stream</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>io.projectreactor</groupId>
+            <artifactId>reactor-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-stream-test-support</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+        <testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+            <plugin>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <configuration>
+                    <args>
+                        <arg>-Xjsr305=strict</arg>
+                    </args>
+                    <compilerPlugins>
+                        <plugin>spring</plugin>
+                    </compilerPlugins>
+                </configuration>
+                <dependencies>
+                    <dependency>
+                        <groupId>org.jetbrains.kotlin</groupId>
+                        <artifactId>kotlin-maven-allopen</artifactId>
+                        <version>${kotlin.version}</version>
+                    </dependency>
+                </dependencies>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.avro</groupId>
+                <artifactId>avro-maven-plugin</artifactId>
+                <version>${avro.version}</version>
+                <executions>
+                    <execution>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>schema</goal>
+                        </goals>
+                        <configuration>
+                            <sourceDirectory>src/main/resources/avro</sourceDirectory>
+                            <outputDirectory>${project.build.directory}/generated-sources</outputDirectory>
+                            <stringType>String</stringType>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>spring-snapshots</id>
+            <name>Spring Snapshots</name>
+            <url>https://repo.spring.io/libs-snapshot-local</url>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+            <releases>
+                <enabled>false</enabled>
+            </releases>
+        </repository>
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/libs-milestone-local</url>
+            <snapshots>
+                <enabled>false</enabled>
+            </snapshots>
+        </repository>
+        <repository>
+            <id>confluent</id>
+            <url>https://packages.confluent.io/maven/</url>
+        </repository>
+    </repositories>
+
+</project>

kafka-e2e-kotlin-sample/customer-service/src/main/kotlin/kafka/e2e/customer/CustomerServiceApplication.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2018 the original author or authors.
+ * Copyright 2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,16 +14,20 @@
  * limitations under the License.
  */
 
-package demo;
+package kafka.e2e.customer
 
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+import org.springframework.cloud.stream.annotation.EnableBinding
+import org.springframework.cloud.stream.messaging.Source
 
+/**
+ * @author José A. Íñigo
+ */
+@EnableBinding(Source::class)
 @SpringBootApplication
-public class MultipleIOChannelsApplication {
-
-	public static void main(String[] args) {
-		SpringApplication.run(MultipleIOChannelsApplication.class, args);
-	}
+class CustomerServiceApplication
 
+fun main(args: Array<String>) {
+    runApplication<CustomerServiceApplication>(*args)
 }

kafka-e2e-kotlin-sample/customer-service/src/main/kotlin/kafka/e2e/customer/service/CustomerService.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kafka.e2e.customer.service
+
+import kafka.e2e.customer.Customer
+
+/**
+ * @author José A. Íñigo
+ */
+interface CustomerService {
+
+    fun save(customer: Customer)
+
+}

kafka-e2e-kotlin-sample/customer-service/src/main/kotlin/kafka/e2e/customer/service/CustomerServiceImpl.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kafka.e2e.customer.service
+
+import kafka.e2e.customer.Customer
+import org.springframework.cloud.stream.messaging.Source
+import org.springframework.kafka.support.KafkaHeaders
+import org.springframework.messaging.support.MessageBuilder
+import org.springframework.stereotype.Service
+
+/**
+ * @author José A. Íñigo
+ */
+@Service
+class CustomerServiceImpl(private val customerKafkaProducer: Source) : CustomerService {
+
+    override fun save(customer: Customer) {
+        val message = MessageBuilder.withPayload(customer).setHeader(KafkaHeaders.MESSAGE_KEY, customer.getId()).build()
+        customerKafkaProducer.output().send(message)
+    }
+}

kafka-e2e-kotlin-sample/customer-service/src/main/kotlin/kafka/e2e/customer/web/CustomerRestController.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kafka.e2e.customer.web
+
+import kafka.e2e.customer.Customer
+import kafka.e2e.customer.service.CustomerService
+import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.RequestBody
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RestController
+
+/**
+ * @author José A. Íñigo
+ */
+@RestController
+@RequestMapping("/customers")
+class CustomerRestController(private val customerService: CustomerService) {
+
+    @PostMapping
+    fun save(@RequestBody customer: Customer) {
+        customerService.save(customer)
+    }
+
+}

kafka-e2e-kotlin-sample/customer-service/src/main/resources/application.yml

@@ -0,0 +1,31 @@
+spring:
+  application:
+    name: customer-service
+  cloud:
+    stream:
+#      schema-registry-client:
+#        endpoint: http://localhost:8081
+      kafka:
+        bindings:
+          output:
+            producer:
+              configuration:
+                key:
+                  serializer: org.apache.kafka.common.serialization.IntegerSerializer
+                value:
+                  serializer: io.confluent.kafka.serializers.KafkaAvroSerializer
+                  subject:
+                    name:
+                      strategy: io.confluent.kafka.serializers.subject.RecordNameStrategy
+                schema:
+                  registry:
+                    url: http://localhost:8081
+      bindings:
+        output:
+          destination: customer
+          producer:
+            useNativeEncoding: true
+
+server:
+  port: 8084
+

kafka-e2e-kotlin-sample/customer-service/src/main/resources/avro/customer.avsc

@@ -0,0 +1,10 @@
+{
+  "namespace" : "kafka.e2e.customer",
+  "type" : "record",
+  "name" : "Customer",
+  "fields" : [
+    {"name":"id","type":"int"},
+    {"name":"name","type":"string"},
+    {"name":"address","type":"string"}
+  ]
+}

kafka-e2e-kotlin-sample/customer-service/src/test/kotlin/kafka/e2e/customer/CustomerServiceApplicationTests.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kafka.e2e.customer
+
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.context.junit4.SpringRunner
+
+/**
+ * @author José A. Íñigo
+ */
+
+@RunWith(SpringRunner::class)
+@SpringBootTest
+class CustomerServiceApplicationTests {
+
+    @Test
+    fun contextLoads() {
+    }
+
+}