Merge pull request #5996 from amit2103/BAEL-10837

[BAEL-10837] - Splitted core-java-concurrency module

core-java-concurrency-advanced/README.md

@@ -1,33 +1,21 @@
 =========
 
-## Core Java Concurrency Examples
+## Core Java Concurrency Advanced Examples
 
 ### Relevant Articles: 
-- [Guide To CompletableFuture](http://www.baeldung.com/java-completablefuture)
-- [A Guide to the Java ExecutorService](http://www.baeldung.com/java-executor-service-tutorial)
 - [Introduction to Thread Pools in Java](http://www.baeldung.com/thread-pool-java-and-guava)
-- [Guide to java.util.concurrent.Future](http://www.baeldung.com/java-future)
 - [Guide to CountDownLatch in Java](http://www.baeldung.com/java-countdown-latch)
 - [Guide to java.util.concurrent.Locks](http://www.baeldung.com/java-concurrent-locks)
 - [An Introduction to ThreadLocal in Java](http://www.baeldung.com/java-threadlocal)
-- [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
 - [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
 - [The Dining Philosophers Problem in Java](http://www.baeldung.com/java-dining-philoshophers)
 - [Guide to the Java Phaser](http://www.baeldung.com/java-phaser)
-- [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
 - [An Introduction to Atomic Variables in Java](http://www.baeldung.com/java-atomic-variables)
 - [CyclicBarrier in Java](http://www.baeldung.com/java-cyclic-barrier)
 - [Guide to Volatile Keyword in Java](http://www.baeldung.com/java-volatile)
-- [Overview of the java.util.concurrent](http://www.baeldung.com/java-util-concurrent)
 - [Semaphores in Java](http://www.baeldung.com/java-semaphore)
 - [Daemon Threads in Java](http://www.baeldung.com/java-daemon-thread)
-- [Implementing a Runnable vs Extending a Thread](http://www.baeldung.com/java-runnable-vs-extending-thread)
-- [How to Kill a Java Thread](http://www.baeldung.com/java-thread-stop)
-- [ExecutorService - Waiting for Threads to Finish](http://www.baeldung.com/java-executor-wait-for-threads)
-- [wait and notify() Methods in Java](http://www.baeldung.com/java-wait-notify)
 - [Priority-based Job Scheduling in Java](http://www.baeldung.com/java-priority-job-schedule)
-- [Life Cycle of a Thread in Java](http://www.baeldung.com/java-thread-lifecycle)
-- [Runnable vs. Callable in Java](http://www.baeldung.com/java-runnable-callable)
 - [Brief Introduction to Java Thread.yield()](https://www.baeldung.com/java-thread-yield)
 - [Print Even and Odd Numbers Using 2 Threads](https://www.baeldung.com/java-even-odd-numbers-with-2-threads)
 - [Java CyclicBarrier vs CountDownLatch](https://www.baeldung.com/java-cyclicbarrier-countdownlatch)

core-java-concurrency-advanced/pom.xml

@@ -2,10 +2,10 @@
     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>
     <groupId>com.baeldung</groupId>
-    <artifactId>core-java-concurrency</artifactId>
+    <artifactId>core-java-concurrency-advanced</artifactId>
     <version>0.1.0-SNAPSHOT</version>
     <packaging>jar</packaging>
-    <name>core-java-concurrency</name>
+    <name>core-java-concurrency-advanced</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -60,7 +60,7 @@
     </dependencies>
 
     <build>
-        <finalName>core-java-concurrency</finalName>
+        <finalName>core-java-concurrency-advanced</finalName>
         <resources>
             <resource>
                 <directory>src/main/resources</directory>

core-java-concurrency-advanced/src/main/java/com/baeldung/concurrent/atomic/SafeCounterWithLock.java

@@ -1,13 +1,13 @@
-package com.baeldung.concurrent.atomic;
-
-public class SafeCounterWithLock {
-    private volatile int counter;
-    
-    int getValue() {
-        return counter;
-    }
-    
-    synchronized void increment() {
-        counter++;
-    }
-}
+package com.baeldung.concurrent.atomic;
+
+public class SafeCounterWithLock {
+    private volatile int counter;
+    
+    int getValue() {
+        return counter;
+    }
+    
+    synchronized void increment() {
+        counter++;
+    }
+}

core-java-concurrency-advanced/src/main/java/com/baeldung/concurrent/atomic/SafeCounterWithoutLock.java

@@ -1,21 +1,21 @@
-package com.baeldung.concurrent.atomic;
-
-import java.util.concurrent.atomic.AtomicInteger;
-
-public class SafeCounterWithoutLock {
-    private final AtomicInteger counter = new AtomicInteger(0);
-    
-    int getValue() {
-        return counter.get();
-    }
-    
-    void increment() {
-        while(true) {
-            int existingValue = getValue();
-            int newValue = existingValue + 1;
-            if(counter.compareAndSet(existingValue, newValue)) {
-                return;
-            }
-        }
-    }
-}
+package com.baeldung.concurrent.atomic;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class SafeCounterWithoutLock {
+    private final AtomicInteger counter = new AtomicInteger(0);
+    
+    int getValue() {
+        return counter.get();
+    }
+    
+    void increment() {
+        while(true) {
+            int existingValue = getValue();
+            int newValue = existingValue + 1;
+            if(counter.compareAndSet(existingValue, newValue)) {
+                return;
+            }
+        }
+    }
+}

core-java-concurrency-advanced/src/main/java/com/baeldung/concurrent/atomic/UnsafeCounter.java

@@ -1,13 +1,13 @@
-package com.baeldung.concurrent.atomic;
-
-public class UnsafeCounter {
-    private int counter;
-    
-    int getValue() {
-        return counter;
-    }
-    
-    void increment() {
-        counter++;
-    }
-}
+package com.baeldung.concurrent.atomic;
+
+public class UnsafeCounter {
+    private int counter;
+    
+    int getValue() {
+        return counter;
+    }
+    
+    void increment() {
+        counter++;
+    }
+}

core-java-concurrency-advanced/src/test/java/com/baeldung/concurrent/atomic/ThreadSafeCounterIntegrationTest.java

@@ -1,38 +1,38 @@
-package com.baeldung.concurrent.atomic;
-
-import static org.junit.Assert.assertEquals;
-
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-import java.util.stream.IntStream;
-
-import org.junit.Test;
-
-public class ThreadSafeCounterIntegrationTest {
-
-    @Test
-    public void givenMultiThread_whenSafeCounterWithLockIncrement() throws InterruptedException {
-        ExecutorService service = Executors.newFixedThreadPool(3);
-        SafeCounterWithLock safeCounter = new SafeCounterWithLock();
-
-        IntStream.range(0, 1000)
-          .forEach(count -> service.submit(safeCounter::increment));
-        service.awaitTermination(100, TimeUnit.MILLISECONDS);
-
-        assertEquals(1000, safeCounter.getValue());
-    }
-    
-    @Test
-    public void givenMultiThread_whenSafeCounterWithoutLockIncrement() throws InterruptedException {
-        ExecutorService service = Executors.newFixedThreadPool(3);
-        SafeCounterWithoutLock safeCounter = new SafeCounterWithoutLock();
-
-        IntStream.range(0, 1000)
-          .forEach(count -> service.submit(safeCounter::increment));
-        service.awaitTermination(100, TimeUnit.MILLISECONDS);
-
-        assertEquals(1000, safeCounter.getValue());
-    }
-    
-}
+package com.baeldung.concurrent.atomic;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.IntStream;
+
+import org.junit.Test;
+
+public class ThreadSafeCounterIntegrationTest {
+
+    @Test
+    public void givenMultiThread_whenSafeCounterWithLockIncrement() throws InterruptedException {
+        ExecutorService service = Executors.newFixedThreadPool(3);
+        SafeCounterWithLock safeCounter = new SafeCounterWithLock();
+
+        IntStream.range(0, 1000)
+          .forEach(count -> service.submit(safeCounter::increment));
+        service.awaitTermination(100, TimeUnit.MILLISECONDS);
+
+        assertEquals(1000, safeCounter.getValue());
+    }
+    
+    @Test
+    public void givenMultiThread_whenSafeCounterWithoutLockIncrement() throws InterruptedException {
+        ExecutorService service = Executors.newFixedThreadPool(3);
+        SafeCounterWithoutLock safeCounter = new SafeCounterWithoutLock();
+
+        IntStream.range(0, 1000)
+          .forEach(count -> service.submit(safeCounter::increment));
+        service.awaitTermination(100, TimeUnit.MILLISECONDS);
+
+        assertEquals(1000, safeCounter.getValue());
+    }
+    
+}

core-java-concurrency-advanced/src/test/java/com/baeldung/concurrent/atomic/ThreadUnsafeCounterManualTest.java

@@ -1,33 +1,33 @@
-package com.baeldung.concurrent.atomic;
-
-import static org.junit.Assert.assertEquals;
-
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
-import java.util.stream.IntStream;
-
-import org.junit.Test;
-
-/**
- * This test shows the behaviour of a thread-unsafe class in a multithreaded scenario. We are calling
- * the increment methods 1000 times from a pool of 3 threads. In most of the cases, the counter will 
- * less than 1000, because of lost updates, however, occasionally it may reach 1000, when no threads
- * called the method simultaneously. This may cause the build to fail occasionally. Hence excluding this
- * test from build by adding this in manual test
- */
-public class ThreadUnsafeCounterManualTest {
-
-    @Test
-    public void givenMultiThread_whenUnsafeCounterIncrement() throws InterruptedException {
-        ExecutorService service = Executors.newFixedThreadPool(3);
-        UnsafeCounter unsafeCounter = new UnsafeCounter();
-
-        IntStream.range(0, 1000)
-          .forEach(count -> service.submit(unsafeCounter::increment));
-        service.awaitTermination(100, TimeUnit.MILLISECONDS);
-
-        assertEquals(1000, unsafeCounter.getValue());
-    }
-    
-}
+package com.baeldung.concurrent.atomic;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.IntStream;
+
+import org.junit.Test;
+
+/**
+ * This test shows the behaviour of a thread-unsafe class in a multithreaded scenario. We are calling
+ * the increment methods 1000 times from a pool of 3 threads. In most of the cases, the counter will 
+ * less than 1000, because of lost updates, however, occasionally it may reach 1000, when no threads
+ * called the method simultaneously. This may cause the build to fail occasionally. Hence excluding this
+ * test from build by adding this in manual test
+ */
+public class ThreadUnsafeCounterManualTest {
+
+    @Test
+    public void givenMultiThread_whenUnsafeCounterIncrement() throws InterruptedException {
+        ExecutorService service = Executors.newFixedThreadPool(3);
+        UnsafeCounter unsafeCounter = new UnsafeCounter();
+
+        IntStream.range(0, 1000)
+          .forEach(count -> service.submit(unsafeCounter::increment));
+        service.awaitTermination(100, TimeUnit.MILLISECONDS);
+
+        assertEquals(1000, unsafeCounter.getValue());
+    }
+    
+}

core-java-concurrency-basic/.gitignore

@@ -0,0 +1,26 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+*.txt
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml

core-java-concurrency-basic/README.md

@@ -0,0 +1,17 @@
+=========
+
+## Core Java Concurrency Basic Examples
+
+### Relevant Articles: 
+- [Guide To CompletableFuture](http://www.baeldung.com/java-completablefuture)
+- [A Guide to the Java ExecutorService](http://www.baeldung.com/java-executor-service-tutorial)
+- [Guide to java.util.concurrent.Future](http://www.baeldung.com/java-future)
+- [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
+- [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
+- [Overview of the java.util.concurrent](http://www.baeldung.com/java-util-concurrent)
+- [Implementing a Runnable vs Extending a Thread](http://www.baeldung.com/java-runnable-vs-extending-thread)
+- [How to Kill a Java Thread](http://www.baeldung.com/java-thread-stop)
+- [ExecutorService - Waiting for Threads to Finish](http://www.baeldung.com/java-executor-wait-for-threads)
+- [wait and notify() Methods in Java](http://www.baeldung.com/java-wait-notify)
+- [Life Cycle of a Thread in Java](http://www.baeldung.com/java-thread-lifecycle)
+- [Runnable vs. Callable in Java](http://www.baeldung.com/java-runnable-callable)

core-java-concurrency-basic/pom.xml

@@ -0,0 +1,55 @@
+<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>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-concurrency-basic</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>core-java-concurrency-basic</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.jayway.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <version>${avaitility.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-concurrency-basic</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <avaitility.version>1.7.0</avaitility.version>
+    </properties>
+
+</project>