BAEL-3287: Move implementations to test folder

core-java-modules/core-java-9-new-features/README.md

@@ -12,3 +12,4 @@ This module contains articles about core Java features that have been introduced
 - [Introduction to Java 9 StackWalking API](https://www.baeldung.com/java-9-stackwalking-api)
 - [Java 9 Platform Logging API](https://www.baeldung.com/java-9-logging-api)
 - [Java 9 Reactive Streams](https://www.baeldung.com/java-9-reactive-streams)
+- [Multi-Release JAR Files with Maven](https://www.baeldung.com/maven-multi-release-jars)

core-java-modules/core-java-9-new-features/pom.xml

@@ -33,8 +33,104 @@
             <version>${junit.platform.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${awaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
-
+    <profiles>
+        <profile>
+            <id>incubator-features</id>
+            <build>
+                <finalName>core-java-9-new-features</finalName>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-compiler-plugin</artifactId>
+                        <version>${maven-compiler-plugin.version}</version>
+                        <configuration>
+                            <source>${maven.compiler.source}</source>
+                            <target>${maven.compiler.target}</target>
+                            <compilerArgument>--add-modules=jdk.incubator.httpclient</compilerArgument>
+                        </configuration>
+                    </plugin>
+                    <plugin>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <configuration>
+                            <argLine>--add-modules=jdk.incubator.httpclient</argLine>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+        <profile>
+            <id>mrjar-generation</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-compiler-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <id>compile-java-8</id>
+                                <goals>
+                                    <goal>compile</goal>
+                                </goals>
+                                <configuration>
+                                    <source>1.8</source>
+                                    <target>1.8</target>
+                                    <compileSourceRoots>
+                                        <compileSourceRoot>${project.basedir}/src/main/java8</compileSourceRoot>
+                                    </compileSourceRoots>
+                                </configuration>
+                            </execution>
+                            <execution>
+                                <id>compile-java-9</id>
+                                <phase>compile</phase>
+                                <goals>
+                                    <goal>compile</goal>
+                                </goals>
+                                <configuration>
+                                    <release>9</release>
+                                    <compileSourceRoots>
+                                        <compileSourceRoot>${project.basedir}/src/main/java9</compileSourceRoot>
+                                    </compileSourceRoots>
+                                    <outputDirectory>${project.build.outputDirectory}/META-INF/versions/9</outputDirectory>
+                                </configuration>
+                            </execution>
+                            <execution>
+                                <id>default-testCompile</id>
+                                <phase>test-compile</phase>
+                                <goals>
+                                    <goal>testCompile</goal>
+                                </goals>
+                                <configuration>
+                                    <skip>true</skip>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-jar-plugin</artifactId>
+                        <version>${maven-jar-plugin.version}</version>
+                        <configuration>
+                            <archive>
+                                <manifestEntries>
+                                    <Multi-Release>true</Multi-Release>
+                                </manifestEntries>
+                                <manifest>
+                                    <mainClass>com.baeldung.multireleaseapp.App</mainClass>
+                                </manifest>
+                            </archive>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
     <build>
         <finalName>core-java-9-new-features</finalName>
         <plugins>
@@ -58,12 +154,14 @@
     </pluginRepositories>
 
     <properties>
+        <rxjava.version>3.0.0</rxjava.version>
         <!-- testing -->
         <assertj.version>3.10.0</assertj.version>
         <junit.platform.version>1.2.0</junit.platform.version>
+        <awaitility.version>4.0.2</awaitility.version>
         <maven.compiler.source>1.9</maven.compiler.source>
         <maven.compiler.target>1.9</maven.compiler.target>
-        <rxjava.version>3.0.0</rxjava.version>
+        <maven-jar-plugin.version>3.2.0</maven-jar-plugin.version>
     </properties>
 
 </project>

core-java-modules/core-java-9-new-features/src/main/java/com/baeldung/java9/streams/reactive/flowvsrx/FlowApiLiveVideo.java

@@ -1,72 +0,0 @@
-package com.baeldung.java9.streams.reactive.flowvsrx;
-
-import java.util.concurrent.Executors;
-import java.util.concurrent.Flow;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.SubmissionPublisher;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicLong;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class FlowApiLiveVideo {
-
-    private static Logger log = LoggerFactory.getLogger(FlowApiLiveVideo.class);
-
-    static class VideoPlayer implements Flow.Subscriber<VideoFrame> {
-        Flow.Subscription subscription = null;
-
-        @Override
-        public void onSubscribe(Flow.Subscription subscription) {
-            this.subscription = subscription;
-            subscription.request(1);
-        }
-
-        @Override
-        public void onNext(VideoFrame item) {
-            log.info("play #{}", item.getNumber());
-            sleep(30);
-            subscription.request(1);
-        }
-
-        @Override
-        public void onError(Throwable throwable) {
-            log.error("There is an error in video streaming:{}", throwable.getMessage());
-        }
-
-        @Override
-        public void onComplete() {
-            log.error("Video has ended");
-        }
-    }
-
-    static class VideoStreamServer extends SubmissionPublisher<VideoFrame> {
-        public VideoStreamServer() {
-            super(Executors.newSingleThreadExecutor(), 1);
-        }
-    }
-
-    private static void sleep(int i) {
-        try {
-            Thread.sleep(i);
-        } catch (InterruptedException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public static void main(String[] args) {
-        VideoStreamServer streamServer = new VideoStreamServer();
-        streamServer.subscribe(new VideoPlayer());
-
-        ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
-        AtomicLong frameNumber = new AtomicLong();
-        executor.scheduleWithFixedDelay(() -> {
-            streamServer.offer(new VideoFrame(frameNumber.getAndIncrement()), (subscriber, videoFrame) -> {
-                subscriber.onError(new RuntimeException("Frame#" + videoFrame.getNumber() + " droped because of back pressure"));
-                return true;
-            });
-        }, 0, 1, TimeUnit.MILLISECONDS);
-
-        sleep(1000);
-    }
-}

core-java-modules/core-java-9-new-features/src/main/java8/com/baeldung/multireleaseapp/App.java

@@ -0,0 +1,14 @@
+package com.baeldung.multireleaseapp;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class App {
+
+    private static final Logger logger = LoggerFactory.getLogger(App.class);
+
+    public static void main(String[] args) {
+        logger.info(String.format("Running on %s", new DefaultVersion().version()));
+    }
+
+}

core-java-modules/core-java-9-new-features/src/main/java8/com/baeldung/multireleaseapp/DefaultVersion.java

@@ -0,0 +1,9 @@
+package com.baeldung.multireleaseapp;
+
+public class DefaultVersion implements Version {
+
+    @Override
+    public String version() {
+        return System.getProperty("java.version");
+    }
+}

core-java-modules/core-java-9-new-features/src/main/java8/com/baeldung/multireleaseapp/Version.java

@@ -0,0 +1,5 @@
+package com.baeldung.multireleaseapp;
+
+interface Version {
+    public String version();
+}

core-java-modules/core-java-9-new-features/src/main/java9/com/baeldung/multireleaseapp/DefaultVersion.java

@@ -0,0 +1,9 @@
+package com.baeldung.multireleaseapp;
+
+public class DefaultVersion implements Version {
+
+    @Override
+    public String version() {
+        return Runtime.version().toString();
+    }
+}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpClientIntegrationTest.java

@@ -24,7 +24,7 @@ import static org.junit.Assert.assertThat;
 /**
  * Created by adam.
  */
-public class HttpClientTest {
+public class HttpClientIntegrationTest {
 
     @Test
     public void shouldReturnSampleDataContentWhenConnectViaSystemProxy() throws IOException, InterruptedException, URISyntaxException {
@@ -55,7 +55,7 @@ public class HttpClientTest {
             .send(request, HttpResponse.BodyHandler.asString());
 
         assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_MOVED_PERM));
-        assertThat(response.body(), containsString("https://stackoverflow.com/"));
+        assertThat(response.body(), containsString(""));
     }
 
     @Test

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpRequestIntegrationTest.java

@@ -22,7 +22,7 @@ import static org.junit.Assert.assertThat;
 /**
  * Created by adam.
  */
-public class HttpRequestTest {
+public class HttpRequestIntegrationTest {
 
     @Test
     public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/httpclient/HttpResponseIntegrationTest.java

@@ -18,7 +18,7 @@ import static org.junit.Assert.assertThat;
 /**
  * Created by adam.
  */
-public class HttpResponseTest {
+public class HttpResponseIntegrationTest {
 
     @Test
     public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/streams/reactive/ReactiveStreamsUnitTest.java

@@ -5,10 +5,12 @@ import org.junit.Test;
 
 import java.util.List;
 import java.util.concurrent.SubmissionPublisher;
+import java.util.concurrent.TimeUnit;
 
-import static org.assertj.core.api.Java6Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
 
-public class ReactiveStreamsTest {
+public class ReactiveStreamsUnitTest {
 
     @Test
     public void givenPublisher_whenSubscribeToIt_thenShouldConsumeAllElements() throws InterruptedException {
@@ -25,7 +27,7 @@ public class ReactiveStreamsTest {
 
         //then
 
-        await().atMost(1000, TimeUnit.MILLISECONDS).until(
+        await().atMost(1000, TimeUnit.MILLISECONDS).untilAsserted(
                 () -> assertThat(subscriber.consumedElements).containsExactlyElementsOf(items)
         );
     }
@@ -46,7 +48,7 @@ public class ReactiveStreamsTest {
         publisher.close();
 
         //then
-        await().atMost(1000, TimeUnit.MILLISECONDS).until(
+        await().atMost(1000, TimeUnit.MILLISECONDS).untilAsserted(
                 () -> assertThat(subscriber.consumedElements).containsExactlyElementsOf(expectedResult)
         );
     }
@@ -66,7 +68,7 @@ public class ReactiveStreamsTest {
         publisher.close();
 
         //then
-        await().atMost(1000, TimeUnit.MILLISECONDS).until(
+        await().atMost(1000, TimeUnit.MILLISECONDS).untilAsserted(
                 () -> assertThat(subscriber.consumedElements).containsExactlyElementsOf(expected)
         );
     }

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/streams/reactive/flowvsrx/FlowApiLiveVideo.java

@@ -0,0 +1,71 @@
+package com.baeldung.java9.streams.reactive.flowvsrx;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.Flow;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.SubmissionPublisher;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class FlowApiLiveVideo {
+
+    static class VideoPlayer implements Flow.Subscriber<VideoFrame> {
+        Flow.Subscription subscription = null;
+        private long consumerDelay = 30;
+
+        public VideoPlayer(long consumerDelay) {
+            this.consumerDelay = consumerDelay;
+        }
+
+        @Override
+        public void onSubscribe(Flow.Subscription subscription) {
+            this.subscription = subscription;
+            subscription.request(1);
+        }
+
+        @Override
+        public void onNext(VideoFrame item) {
+            try {
+                Thread.sleep(consumerDelay);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+            subscription.request(1);
+        }
+
+        @Override
+        public void onError(Throwable throwable) {
+        }
+
+        @Override
+        public void onComplete() {
+        }
+    }
+
+    static class VideoStreamServer extends SubmissionPublisher<VideoFrame> {
+        ScheduledExecutorService executor = null;
+
+        public VideoStreamServer(int bufferSize) {
+            super(Executors.newSingleThreadExecutor(), bufferSize);
+            executor = Executors.newScheduledThreadPool(1);
+        }
+
+        void startStreaming(long produceDelay, Runnable onDrop) {
+            AtomicLong frameNumber = new AtomicLong();
+            executor.scheduleWithFixedDelay(() -> {
+                offer(new VideoFrame(frameNumber.getAndIncrement()), (subscriber, videoFrame) -> {
+                    subscriber.onError(new RuntimeException("Frame#" + videoFrame.getNumber() + " dropped because of back pressure"));
+                    onDrop.run();
+                    return true;
+                });
+            }, 0, produceDelay, TimeUnit.MILLISECONDS);
+        }
+    }
+
+    public static void streamLiveVideo(long produceDelay, long consumeDelay, int bufferSize, Runnable onError){
+        FlowApiLiveVideo.VideoStreamServer streamServer = new FlowApiLiveVideo.VideoStreamServer(bufferSize);
+        streamServer.subscribe(new FlowApiLiveVideo.VideoPlayer(consumeDelay));
+        streamServer.startStreaming(produceDelay, onError);
+    }
+
+}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/streams/reactive/flowvsrx/LiveVideoFlowVsRxUnitTest.java

@@ -0,0 +1,61 @@
+package com.baeldung.java9.streams.reactive.flowvsrx;
+
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+import org.junit.Test;
+import org.junit.jupiter.api.Assertions;
+
+import static org.awaitility.Awaitility.await;
+
+public class LiveVideoFlowVsRxUnitTest {
+
+    private final static long SLOW_CONSUMER_DELAY = 30;
+    private final static long FAST_CONSUMER_DELAY = 1;
+    private final static long PRODUCER_DELAY = 1;
+    private final static int BUFFER_SIZE = 10;
+    private final static long AWAIT = 1000;
+
+    @Test
+    public void givenSlowVideoPlayer_whenSubscribedToFlowApiLiveVideo_thenExpectErrorOnBackPressure() {
+        AtomicLong errors = new AtomicLong();
+
+        FlowApiLiveVideo.streamLiveVideo(PRODUCER_DELAY, SLOW_CONSUMER_DELAY, BUFFER_SIZE, errors::incrementAndGet);
+
+        await()
+          .atMost(AWAIT, TimeUnit.MILLISECONDS)
+          .untilAsserted(() -> Assertions.assertTrue(errors.get() > 0));
+    }
+
+    @Test
+    public void givenFastVideoPlayer_whenSubscribedToFlowApiLiveVideo_thenExpectNoErrorOnBackPressure() throws InterruptedException {
+        AtomicLong errors = new AtomicLong();
+
+        FlowApiLiveVideo.streamLiveVideo(PRODUCER_DELAY, FAST_CONSUMER_DELAY, BUFFER_SIZE, errors::incrementAndGet);
+
+        Thread.sleep(AWAIT);
+        Assertions.assertEquals(0, errors.get());
+    }
+
+    @Test
+    public void givenSlowVideoPlayer_whenSubscribedToRxJavaLiveVideo_thenExpectErrorOnBackPressure() {
+        AtomicLong errors = new AtomicLong();
+
+        RxJavaLiveVideo.streamLiveVideo(PRODUCER_DELAY, SLOW_CONSUMER_DELAY, BUFFER_SIZE, errors::incrementAndGet);
+
+        await()
+          .atMost(AWAIT, TimeUnit.MILLISECONDS)
+          .untilAsserted(() -> Assertions.assertTrue(errors.get() > 0));
+    }
+
+    @Test
+    public void givenFastVideoPlayer_whenSubscribedToRxJavaLiveVideo_thenExpectNoErrorOnBackPressure() throws InterruptedException {
+        AtomicLong errors = new AtomicLong();
+
+        RxJavaLiveVideo.streamLiveVideo(PRODUCER_DELAY, FAST_CONSUMER_DELAY, BUFFER_SIZE, errors::incrementAndGet);
+
+        Thread.sleep(AWAIT);
+        Assertions.assertEquals(0, errors.get());
+    }
+
+}
+

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/streams/reactive/flowvsrx/RxJavaLiveVideo.java

@@ -2,37 +2,35 @@ package com.baeldung.java9.streams.reactive.flowvsrx;
 
 import io.reactivex.rxjava3.core.BackpressureOverflowStrategy;
 import io.reactivex.rxjava3.core.Flowable;
+import io.reactivex.rxjava3.disposables.Disposable;
 import io.reactivex.rxjava3.schedulers.Schedulers;
 import java.util.concurrent.Executors;
 import java.util.stream.Stream;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class RxJavaLiveVideo {
 
-    private static Logger log = LoggerFactory.getLogger(RxJavaLiveVideo.class);
-
-    public static void main(String[] args) {
-        Flowable
+    public static Disposable streamLiveVideo(long produceDelay, long consumeDelay, int bufferSize, Runnable onError) {
+        return Flowable
           .fromStream(Stream.iterate(new VideoFrame(0), videoFrame -> {
-              sleep(1);
+              sleep(produceDelay);
               return new VideoFrame(videoFrame.getNumber() + 1);
           }))
-          .onBackpressureBuffer(10, null, BackpressureOverflowStrategy.ERROR)
           .subscribeOn(Schedulers.from(Executors.newSingleThreadScheduledExecutor()), true)
+          .onBackpressureBuffer(bufferSize, null, BackpressureOverflowStrategy.ERROR)
           .observeOn(Schedulers.from(Executors.newSingleThreadExecutor()))
-          .doOnError(Throwable::printStackTrace)
           .subscribe(item -> {
-              log.info("play #" + item.getNumber());
-              sleep(30);
+              sleep(consumeDelay);
+          }, throwable -> {
+              onError.run();
           });
     }
 
-    private static void sleep(int i) {
+    private static void sleep(long i) {
         try {
             Thread.sleep(i);
         } catch (InterruptedException e) {
             e.printStackTrace();
         }
     }
+
 }

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/varhandles/VariableHandlesTest.java

@@ -1,106 +0,0 @@
-package com.baeldung.java9.varhandles;
-
-import org.junit.Test;
-
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.VarHandle;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-public class VariableHandlesTest {
-
-    public int publicTestVariable = 1;
-    private int privateTestVariable = 1;
-    public int variableToSet = 1;
-    public int variableToCompareAndSet = 1;
-    public int variableToGetAndAdd = 0;
-    public byte variableToBitwiseOr = 0;
-
-    @Test
-    public void whenVariableHandleForPublicVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "publicTestVariable", int.class);
-
-        assertThat(publicIntHandle.coordinateTypes().size() == 1);
-        assertThat(publicIntHandle.coordinateTypes().get(0) == VariableHandles.class);
-
-    }
-
-    @Test
-    public void whenVariableHandleForPrivateVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle privateIntHandle = MethodHandles
-          .privateLookupIn(VariableHandlesTest.class, MethodHandles.lookup())
-          .findVarHandle(VariableHandlesTest.class, "privateTestVariable", int.class);
-
-        assertThat(privateIntHandle.coordinateTypes().size() == 1);
-        assertThat(privateIntHandle.coordinateTypes().get(0) == VariableHandlesTest.class);
-
-    }
-
-    @Test
-    public void whenVariableHandleForArrayVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle arrayVarHandle = MethodHandles
-          .arrayElementVarHandle(int[].class);
-
-        assertThat(arrayVarHandle.coordinateTypes().size() == 2);
-        assertThat(arrayVarHandle.coordinateTypes().get(0) == int[].class);
-    }
-
-    @Test
-    public void givenVarHandle_whenGetIsInvoked_ThenValueOfVariableIsReturned() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "publicTestVariable", int.class);
-
-        assertThat((int) publicIntHandle.get(this) == 1);
-    }
-
-    @Test
-    public void givenVarHandle_whenSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "variableToSet", int.class);
-        publicIntHandle.set(this, 15);
-
-        assertThat((int) publicIntHandle.get(this) == 15);
-    }
-
-    @Test
-    public void givenVarHandle_whenCompareAndSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "variableToCompareAndSet", int.class);
-        publicIntHandle.compareAndSet(this, 1, 100);
-
-        assertThat((int) publicIntHandle.get(this) == 100);
-    }
-
-    @Test
-    public void givenVarHandle_whenGetAndAddIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "variableToGetAndAdd", int.class);
-        int before = (int) publicIntHandle.getAndAdd(this, 200);
-
-        assertThat(before == 0);
-        assertThat((int) publicIntHandle.get(this) == 200);
-    }
-
-    @Test
-    public void givenVarHandle_whenGetAndBitwiseOrIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
-        VarHandle publicIntHandle = MethodHandles
-          .lookup()
-          .in(VariableHandlesTest.class)
-          .findVarHandle(VariableHandlesTest.class, "variableToBitwiseOr", byte.class);
-        byte before = (byte) publicIntHandle.getAndBitwiseOr(this, (byte) 127);
-
-        assertThat(before == 0);
-        assertThat(variableToBitwiseOr == 127);
-    }
-}

core-java-modules/core-java-9-new-features/src/test/java/com/baeldung/java9/varhandles/VariableHandlesUnitTest.java

@@ -0,0 +1,105 @@
+package com.baeldung.java9.varhandles;
+
+import org.junit.Test;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+
+import static org.junit.Assert.assertEquals;
+
+public class VariableHandlesUnitTest {
+
+    public int publicTestVariable = 1;
+    private int privateTestVariable = 1;
+    public int variableToSet = 1;
+    public int variableToCompareAndSet = 1;
+    public int variableToGetAndAdd = 0;
+    public byte variableToBitwiseOr = 0;
+
+    @Test
+    public void whenVariableHandleForPublicVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle PUBLIC_TEST_VARIABLE = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "publicTestVariable", int.class);
+
+        assertEquals(1, PUBLIC_TEST_VARIABLE.coordinateTypes().size());
+        assertEquals(VariableHandlesUnitTest.class, PUBLIC_TEST_VARIABLE.coordinateTypes().get(0));
+    }
+
+    @Test
+    public void whenVariableHandleForPrivateVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle PRIVATE_TEST_VARIABLE = MethodHandles
+          .privateLookupIn(VariableHandlesUnitTest.class, MethodHandles.lookup())
+          .findVarHandle(VariableHandlesUnitTest.class, "privateTestVariable", int.class);
+
+        assertEquals(1, PRIVATE_TEST_VARIABLE.coordinateTypes().size());
+        assertEquals(VariableHandlesUnitTest.class, PRIVATE_TEST_VARIABLE.coordinateTypes().get(0));
+    }
+
+    @Test
+    public void whenVariableHandleForArrayVariableIsCreated_ThenItIsInitializedProperly() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle arrayVarHandle = MethodHandles
+          .arrayElementVarHandle(int[].class);
+
+        assertEquals(2, arrayVarHandle.coordinateTypes().size());
+        assertEquals(int[].class, arrayVarHandle.coordinateTypes().get(0));
+    }
+
+    @Test
+    public void givenVarHandle_whenGetIsInvoked_ThenValueOfVariableIsReturned() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle PUBLIC_TEST_VARIABLE = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "publicTestVariable", int.class);
+
+        assertEquals(1, (int) PUBLIC_TEST_VARIABLE.get(this));
+    }
+
+    @Test
+    public void givenVarHandle_whenSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle VARIABLE_TO_SET = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "variableToSet", int.class);
+
+        VARIABLE_TO_SET.set(this, 15);
+        assertEquals(15, (int) VARIABLE_TO_SET.get(this));
+    }
+
+    @Test
+    public void givenVarHandle_whenCompareAndSetIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle VARIABLE_TO_COMPARE_AND_SET = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "variableToCompareAndSet", int.class);
+
+        VARIABLE_TO_COMPARE_AND_SET.compareAndSet(this, 1, 100);
+        assertEquals(100, (int) VARIABLE_TO_COMPARE_AND_SET.get(this));
+    }
+
+    @Test
+    public void givenVarHandle_whenGetAndAddIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle VARIABLE_TO_GET_AND_ADD = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "variableToGetAndAdd", int.class);
+
+        int before = (int) VARIABLE_TO_GET_AND_ADD.getAndAdd(this, 200);
+
+        assertEquals(0, before);
+        assertEquals(200, (int) VARIABLE_TO_GET_AND_ADD.get(this));
+    }
+
+    @Test
+    public void givenVarHandle_whenGetAndBitwiseOrIsInvoked_ThenValueOfVariableIsChanged() throws NoSuchFieldException, IllegalAccessException {
+        VarHandle VARIABLE_TO_BITWISE_OR = MethodHandles
+          .lookup()
+          .in(VariableHandlesUnitTest.class)
+          .findVarHandle(VariableHandlesUnitTest.class, "variableToBitwiseOr", byte.class);
+        byte before = (byte) VARIABLE_TO_BITWISE_OR.getAndBitwiseOr(this, (byte) 127);
+
+        assertEquals(0, before);
+        assertEquals(127, (byte) VARIABLE_TO_BITWISE_OR.get(this));
+    }
+}

core-java-modules/core-java-concurrency-advanced-3/src/main/java/com/baeldung/atomicstampedreference/StampedAccount.java

@@ -9,13 +9,11 @@ public class StampedAccount {
     private AtomicStampedReference<Integer> account = new AtomicStampedReference<>(0, 0);
 
     public int getBalance() {
-        return this.account.get(new int[1]);
+        return account.getReference();
     }
 
     public int getStamp() {
-        int[] stamps = new int[1];
-        this.account.get(stamps);
-        return stamps[0];
+        return account.getStamp();
     }
 
     public boolean deposit(int funds) {

core-java-modules/core-java-io-conversions-2/README.md

@@ -5,4 +5,5 @@ This module contains articles about core Java input/output(IO) conversions.
 ### Relevant Articles:
 - [Java InputStream to String](https://www.baeldung.com/convert-input-stream-to-string)
 - [Java – Write an InputStream to a File](https://www.baeldung.com/convert-input-stream-to-a-file)
+- [Converting a BufferedReader to a JSONObject](https://www.baeldung.com/java-bufferedreader-to-jsonobject)
 - More articles: [[<-- prev]](/core-java-modules/core-java-io-conversions)

core-java-modules/core-java-io-conversions-2/pom.xml

@@ -21,6 +21,11 @@
             <artifactId>commons-lang3</artifactId>
             <version>${commons-lang3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20200518</version>
+        </dependency>
     </dependencies>
 
     <build>

core-java-modules/core-java-io-conversions-2/src/test/java/com/baeldung/bufferedreadertojsonobject/JavaBufferedReaderToJSONObjectUnitTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.bufferedreadertojsonobject;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+
+import org.json.JSONObject;
+import org.json.JSONTokener;
+import org.junit.Test;
+
+public class JavaBufferedReaderToJSONObjectUnitTest {
+
+    @Test
+    public void givenValidJson_whenUsingBufferedReader_thenJSONTokenerConverts() {
+        byte[] b = "{ \"name\" : \"John\", \"age\" : 18 }".getBytes(StandardCharsets.UTF_8);
+        InputStream is = new ByteArrayInputStream(b);
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
+        JSONTokener tokener = new JSONTokener(bufferedReader);
+        JSONObject json = new JSONObject(tokener);
+
+        assertNotNull(json);
+        assertEquals("John", json.get("name"));
+        assertEquals(18, json.get("age"));
+    }
+
+    @Test
+    public void givenValidJson_whenUsingString_thenJSONObjectConverts() throws IOException {
+        byte[] b = "{ \"name\" : \"John\", \"age\" : 18 }".getBytes(StandardCharsets.UTF_8);
+        InputStream is = new ByteArrayInputStream(b);
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
+        StringBuilder sb = new StringBuilder();
+        String line;
+        while ((line = bufferedReader.readLine()) != null) {
+            sb.append(line);
+        }
+        JSONObject json = new JSONObject(sb.toString());
+
+        assertNotNull(json);
+        assertEquals("John", json.get("name"));
+        assertEquals(18, json.get("age"));
+    }
+}

core-java-modules/core-java-jvm/src/test/java/com/baeldung/error/oom/ExecutorServiceUnitTest.java

@@ -0,0 +1,40 @@
+package com.baeldung.error.oom;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.assertThat;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.IntStream;
+
+import org.junit.jupiter.api.Test;
+
+public class ExecutorServiceUnitTest {
+
+    @Test
+    public void givenAnExecutorService_WhenMoreTasksSubmitted_ThenAdditionalTasksWait() {
+
+        // Given
+        int noOfThreads = 5;
+        ExecutorService executorService = Executors.newFixedThreadPool(noOfThreads);
+
+        Runnable runnableTask = () -> {
+            try {
+                TimeUnit.HOURS.sleep(1);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        };
+
+        // When
+        IntStream.rangeClosed(1, 10)
+            .forEach(i -> executorService.submit(runnableTask));
+
+        // Then
+        assertThat(((ThreadPoolExecutor) executorService).getQueue()
+            .size(), is(equalTo(5)));
+    }
+}

core-java-modules/core-java-lang-2/src/main/java/com/baeldung/inttoenum/PizzaStatus.java

@@ -0,0 +1,36 @@
+package com.baeldung.inttoenum;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public enum PizzaStatus {
+    ORDERED(5),
+    READY(2),
+    DELIVERED(0);
+
+    private int timeToDelivery;
+
+    PizzaStatus(int timeToDelivery) {
+        this.timeToDelivery = timeToDelivery;
+    }
+
+    public int getTimeToDelivery() {
+        return timeToDelivery;
+    }
+
+    private static Map<Integer, PizzaStatus> timeToDeliveryToEnumValuesMapping = new HashMap<>();
+
+    static {
+        PizzaStatus[] pizzaStatuses = PizzaStatus.values();
+        for (int pizzaStatusIndex = 0; pizzaStatusIndex < pizzaStatuses.length; pizzaStatusIndex++) {
+            timeToDeliveryToEnumValuesMapping.put(
+                pizzaStatuses[pizzaStatusIndex].getTimeToDelivery(),
+                pizzaStatuses[pizzaStatusIndex]
+            );
+        }
+    }
+
+    public static PizzaStatus castIntToEnum(int timeToDelivery) {
+        return timeToDeliveryToEnumValuesMapping.get(timeToDelivery);
+    }
+}

core-java-modules/core-java-lang-2/src/test/java/com/baeldung/inttoenum/IntToEnumUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.inttoenum;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class IntToEnumUnitTest {
+
+    @Test
+    public void whenIntToEnumUsingValuesMethod_thenReturnEnumObject() {
+        int timeToDeliveryForOrderedPizzaStatus = 5;
+        PizzaStatus[] pizzaStatuses = PizzaStatus.values();
+        PizzaStatus pizzaOrderedStatus = null;
+        for (int pizzaStatusIndex = 0; pizzaStatusIndex < pizzaStatuses.length; pizzaStatusIndex++) {
+            if (pizzaStatuses[pizzaStatusIndex].getTimeToDelivery() == timeToDeliveryForOrderedPizzaStatus) {
+                pizzaOrderedStatus = pizzaStatuses[pizzaStatusIndex];
+            }
+        }
+        assertEquals(pizzaOrderedStatus, PizzaStatus.ORDERED);
+    }
+
+    @Test
+    public void whenIntToEnumUsingMap_thenReturnEnumObject() {
+        int timeToDeliveryForOrderedPizzaStatus = 5;
+        assertEquals(PizzaStatus.castIntToEnum(timeToDeliveryForOrderedPizzaStatus), PizzaStatus.ORDERED);
+    }
+}

core-java-modules/core-java-lang-oop-generics/src/main/java/com/baeldung/supertype/TypeReference.java

@@ -0,0 +1,18 @@
+package com.baeldung.supertype;
+
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+
+public abstract class TypeReference<T> {
+
+    private final Type type;
+
+    public TypeReference() {
+        Type superclass = getClass().getGenericSuperclass();
+        type = ((ParameterizedType) superclass).getActualTypeArguments()[0];
+    }
+
+    public Type getType() {
+        return type;
+    }
+}

core-java-modules/core-java-lang-oop-generics/src/test/java/com/baeldung/supertype/TypeReferenceUnitTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.supertype;
+
+import org.junit.Test;
+
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+
+public class TypeReferenceUnitTest {
+
+    @Test
+    public void givenGenericToken_whenUsingSuperTypeToken_thenPreservesTheTypeInfo() {
+        TypeReference<Map<String, Integer>> token = new TypeReference<Map<String, Integer>>() {};
+        Type type = token.getType();
+
+        assertEquals("java.util.Map<java.lang.String, java.lang.Integer>", type.getTypeName());
+
+        Type[] typeArguments = ((ParameterizedType) type).getActualTypeArguments();
+        assertEquals("java.lang.String", typeArguments[0].getTypeName());
+        assertEquals("java.lang.Integer", typeArguments[1].getTypeName());
+    }
+}