Adding 100-2 App, Functional Programming Intro for SCS

scs-100-2/.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/

scs-100-2/README.md

@@ -0,0 +1,58 @@
+# SCS-100-2
+
+## Functional Programming (For Alternative of SCS-100 Project)
+
+A simple Example of an Event Driven Flow by the help of **SPRING CLOUD STREAM KAFKA**
+
+##### properties
+
+* java.version: `11`
+* spring-cloud.version: `2020.0.3` 
+* spring-boot.version: `2.5.2`
+
+![General Flow Diagram](material/kafka-events-intro-100.svg)
+
+The Docker-compose file contains: single kafka and zookeeper. just simply run the following command
+
+```shell
+docker-compose up -d
+```
+
+_Note: I assume you already have docker setup in your machine._
+
+### Make the project
+
+run the following command line to create you jar file in `target` directory
+
+```shell
+mvn clean package
+```
+
+Then run the generated jar file in `target` folder, (so make sure you are in the same directory when you run the jar file
+or give the full path)
+
+```shell
+java -jar scs-100-0.0.1-SNAPSHOT.jar
+```
+
+the application starts to listen on port 8080. make sure that port not being occupied by any other app already, if is try
+to pass the following parameter before `-jar` by adding `-Dserver.port=8081` as:
+
+```shell
+java -Dserver.port=8081 -jar scs-100-0.0.1-SNAPSHOT.jar
+```
+
+_Note: you can also modify the application.yml and set the same properties based on your app profile_
+
+At this point you should have already seen the information about your topics.
+
+### Check Application
+
+#### Create Order or Place your Order
+you should now be able to place your order by calling the following `curl` command
+
+```shell
+# assuming your app is listening on 8080
+ORDER_UUID=$(curl --silent -H 'Content-Type: application/json' -d "{\"itemName\":\"book\"}" http://localhost:8080/order | jq -r '.orderUuid') && for i in `seq 1 15`; do echo $(curl --silent "http://localhost:8080/order/status/"$ORDER_UUID); sleep 1; done;
+```
+Note: make sure you have already installed the `jq` 

scs-100-2/docker-compose.yml

@@ -0,0 +1,19 @@
+version: '3'
+services:
+  kafka:
+    image: wurstmeister/kafka
+    container_name: kafka-mc
+    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

scs-100-2/pom.xml

@@ -0,0 +1,81 @@
+<?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>2.5.2</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <groupId>com.ehsaniara.scs_kafka_intro</groupId>
+    <artifactId>scs-100-2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>scs-100-2</name>
+    <description>Demo project for Spring Boot</description>
+
+    <properties>
+        <java.version>11</java.version>
+        <spring-cloud.version>2020.0.3</spring-cloud.version>
+        <spring-boot.version>${project.parent.version}</spring-boot.version>
+    </properties>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-stream-binder-kafka-streams</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+    </dependencies>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.cloud</groupId>
+                <artifactId>spring-cloud-dependencies</artifactId>
+                <version>${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>
+                <version>${spring-boot.version}</version>
+                <configuration>
+                    <excludes>
+                        <exclude>
+                            <groupId>org.projectlombok</groupId>
+                            <artifactId>lombok</artifactId>
+                        </exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+
+</project>

scs-100-2/src/main/java/com/ehsaniara/scs_kafka_intro/scs1002/Application.java

@@ -0,0 +1,24 @@
+package com.ehsaniara.scs_kafka_intro.scs1002;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.kafka.common.serialization.Serde;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.kafka.support.serializer.JsonSerde;
+
+@SpringBootApplication
+public class Application {
+
+    final static String STATE_STORE_NAME = "scs-100-2-order-events";
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+    @Bean
+    public Serde<Order> orderJsonSerde() {
+        return new JsonSerde<>(Order.class, new ObjectMapper());
+    }
+
+}

scs-100-2/src/main/java/com/ehsaniara/scs_kafka_intro/scs1002/Order.java

@@ -0,0 +1,23 @@
+package com.ehsaniara.scs_kafka_intro.scs1002;
+
+import lombok.*;
+
+import javax.validation.constraints.NotBlank;
+import java.io.Serializable;
+import java.util.UUID;
+
+@ToString
+@Builder
+@Setter
+@Getter
+@AllArgsConstructor
+@NoArgsConstructor
+public class Order implements Serializable {
+
+    private UUID orderUuid;
+
+    @NotBlank
+    private String itemName;
+
+    private OrderStatus orderStatus;
+}

scs-100-2/src/main/java/com/ehsaniara/scs_kafka_intro/scs1002/OrderNotFoundException.java

@@ -0,0 +1,11 @@
+package com.ehsaniara.scs_kafka_intro.scs1002;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(value = HttpStatus.NOT_FOUND)
+public class OrderNotFoundException extends RuntimeException {
+    public OrderNotFoundException(String msg) {
+        super(msg);
+    }
+}

scs-100-2/src/main/java/com/ehsaniara/scs_kafka_intro/scs1002/OrderStatus.java

@@ -0,0 +1,18 @@
+package com.ehsaniara.scs_kafka_intro.scs1002;
+
+import lombok.AllArgsConstructor;
+
+@AllArgsConstructor
+public enum OrderStatus {
+    PENDING("PENDING"),
+    INVENTORY_CHECKING("INVENTORY_CHECKING"),
+    OUT_OF_STOCK("OUT_OF_STOCK"),
+    SHIPPED("SHIPPED"),
+    CANCELED("CANCELED");
+
+    private final String name;
+
+    public String toString() {
+        return this.name;
+    }
+}