[BAEL-9555] - Created a core-java-modules folder

2019-05-05 17:22:09 +05:30
parent 8b63b0d90a
commit 3bae5e5334
1480 changed files with 25600 additions and 5594 deletions
@@ -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
@@ -0,0 +1,25 @@
+=========
+
+## Core Java Concurrency Advanced Examples
+
+### Relevant Articles: 
+- [Introduction to Thread Pools in Java](http://www.baeldung.com/thread-pool-java-and-guava)
+- [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)
+- [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)
+- [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 the Volatile Keyword in Java](http://www.baeldung.com/java-volatile)
+- [Semaphores in Java](http://www.baeldung.com/java-semaphore)
+- [Daemon Threads in Java](http://www.baeldung.com/java-daemon-thread)
+- [Priority-based Job Scheduling in Java](http://www.baeldung.com/java-priority-job-schedule)
+- [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)
+- [Guide to the Fork/Join Framework in Java](http://www.baeldung.com/java-fork-join)
+- [Guide to ThreadLocalRandom in Java](http://www.baeldung.com/java-thread-local-random)
+- [The Thread.join() Method in Java](http://www.baeldung.com/java-thread-join)
+- [Passing Parameters to Java Threads](https://www.baeldung.com/java-thread-parameters)
@@ -0,0 +1,86 @@
+<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-advanced</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-concurrency-advanced</name>
+    <packaging>jar</packaging>
+
+    <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-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>commons-io</groupId>
+            <artifactId>commons-io</artifactId>
+            <version>${commons-io.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-math3</artifactId>
+            <version>${commons-math3.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>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator-annprocess.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-concurrency-advanced</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <!-- util -->
+        <guava.version>21.0</guava.version>
+        <commons-lang3.version>3.5</commons-lang3.version>
+        <commons-math3.version>3.6.1</commons-math3.version>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <collections-generic.version>4.01</collections-generic.version>
+        <!-- testing -->
+        <assertj.version>3.6.1</assertj.version>
+        <avaitility.version>1.7.0</avaitility.version>
+        <jmh-core.version>1.19</jmh-core.version>
+        <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
+    </properties>
+
+</project>
@@ -0,0 +1,13 @@
+package com.baeldung.concurrent.atomic;
+
+public class SafeCounterWithLock {
+    private volatile int counter;
+    
+    int getValue() {
+        return counter;
+    }
+    
+    synchronized void increment() {
+        counter++;
+    }
+}
@@ -0,0 +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;
+            }
+        }
+    }
+}
@@ -0,0 +1,13 @@
+package com.baeldung.concurrent.atomic;
+
+public class UnsafeCounter {
+    private int counter;
+    
+    int getValue() {
+        return counter;
+    }
+    
+    void increment() {
+        counter++;
+    }
+}
@@ -0,0 +1,23 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+
+public class BrokenWorker implements Runnable {
+    private final List<String> outputScraper;
+    private final CountDownLatch countDownLatch;
+
+    BrokenWorker(final List<String> outputScraper, final CountDownLatch countDownLatch) {
+        this.outputScraper = outputScraper;
+        this.countDownLatch = countDownLatch;
+    }
+
+    @Override
+    public void run() {
+        if (true) {
+            throw new RuntimeException("Oh dear");
+        }
+        countDownLatch.countDown();
+        outputScraper.add("Counted down");
+    }
+}
@@ -0,0 +1,33 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.concurrent.CountDownLatch;
+
+public class CountdownLatchCountExample {
+
+    private int count;
+
+    public CountdownLatchCountExample(int count) {
+        this.count = count;
+    }
+
+    public boolean callTwiceInSameThread() {
+        CountDownLatch countDownLatch = new CountDownLatch(count);
+        Thread t = new Thread(() -> {
+            countDownLatch.countDown();
+            countDownLatch.countDown();
+        });
+        t.start();
+
+        try {
+            countDownLatch.await();
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return countDownLatch.getCount() == 0;
+    }
+
+    public static void main(String[] args) {
+        CountdownLatchCountExample ex = new CountdownLatchCountExample(2);
+        System.out.println("Is CountDown Completed : " + ex.callTwiceInSameThread());
+    }
+}
@@ -0,0 +1,41 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CountdownLatchResetExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+
+    CountdownLatchResetExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countWaits() {
+        CountDownLatch countDownLatch = new CountDownLatch(count);
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                long prevValue = countDownLatch.getCount();
+                countDownLatch.countDown();
+                if (countDownLatch.getCount() != prevValue) {
+                    updateCount.incrementAndGet();
+                }               
+            });
+        }
+        
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CountdownLatchResetExample ex = new CountdownLatchResetExample(5, 20);
+        System.out.println("Count : " + ex.countWaits());
+    }
+}
@@ -0,0 +1,34 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+
+public class WaitingWorker implements Runnable {
+
+    private final List<String> outputScraper;
+    private final CountDownLatch readyThreadCounter;
+    private final CountDownLatch callingThreadBlocker;
+    private final CountDownLatch completedThreadCounter;
+
+    WaitingWorker(final List<String> outputScraper, final CountDownLatch readyThreadCounter, final CountDownLatch callingThreadBlocker, CountDownLatch completedThreadCounter) {
+
+        this.outputScraper = outputScraper;
+        this.readyThreadCounter = readyThreadCounter;
+        this.callingThreadBlocker = callingThreadBlocker;
+        this.completedThreadCounter = completedThreadCounter;
+    }
+
+    @Override
+    public void run() {
+        // Mark this thread as read / started
+        readyThreadCounter.countDown();
+        try {
+            callingThreadBlocker.await();
+            outputScraper.add("Counted down");
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        } finally {
+            completedThreadCounter.countDown();
+        }
+    }
+}
@@ -0,0 +1,22 @@
+package com.baeldung.concurrent.countdownlatch;
+
+import java.util.List;
+import java.util.concurrent.CountDownLatch;
+
+public class Worker implements Runnable {
+    private final List<String> outputScraper;
+    private final CountDownLatch countDownLatch;
+
+    Worker(final List<String> outputScraper, final CountDownLatch countDownLatch) {
+        this.outputScraper = outputScraper;
+        this.countDownLatch = countDownLatch;
+    }
+
+    @Override
+    public void run() {
+        // Do some work
+        System.out.println("Doing some logic");
+        outputScraper.add("Counted down");
+        countDownLatch.countDown();
+    }
+}
@@ -0,0 +1,45 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CyclicBarrierCompletionMethodExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+    
+    CyclicBarrierCompletionMethodExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countTrips() {
+
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count, () -> {
+            updateCount.incrementAndGet();
+        });
+
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                try {
+                    cyclicBarrier.await();
+                } catch (InterruptedException | BrokenBarrierException e) {
+                    e.printStackTrace();
+                }
+            });
+        }
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierCompletionMethodExample ex = new CyclicBarrierCompletionMethodExample(5, 20);
+        System.out.println("Count : " + ex.countTrips());
+    }
+}
@@ -0,0 +1,32 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+
+public class CyclicBarrierCountExample {
+
+    private int count;
+
+    public CyclicBarrierCountExample(int count) {
+        this.count = count;
+    }
+
+    public boolean callTwiceInSameThread() {
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count);
+        Thread t = new Thread(() -> {
+            try {
+                cyclicBarrier.await();
+                cyclicBarrier.await();
+            } catch (InterruptedException | BrokenBarrierException e) {
+                e.printStackTrace();
+            }
+        });
+        t.start();
+        return cyclicBarrier.isBroken();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierCountExample ex = new CyclicBarrierCountExample(7);
+        System.out.println("Count : " + ex.callTwiceInSameThread());
+    }
+}
@@ -0,0 +1,77 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+
+public class CyclicBarrierDemo {
+
+    private CyclicBarrier cyclicBarrier;
+    private List<List<Integer>> partialResults = Collections.synchronizedList(new ArrayList<>());
+    private Random random = new Random();
+    private int NUM_PARTIAL_RESULTS;
+    private int NUM_WORKERS;
+
+    private void runSimulation(int numWorkers, int numberOfPartialResults) {
+        NUM_PARTIAL_RESULTS = numberOfPartialResults;
+        NUM_WORKERS = numWorkers;
+
+        cyclicBarrier = new CyclicBarrier(NUM_WORKERS, new AggregatorThread());
+        System.out.println("Spawning " + NUM_WORKERS + " worker threads to compute " + NUM_PARTIAL_RESULTS + " partial results each");
+        for (int i = 0; i < NUM_WORKERS; i++) {
+            Thread worker = new Thread(new NumberCruncherThread());
+            worker.setName("Thread " + i);
+            worker.start();
+        }
+    }
+
+    class NumberCruncherThread implements Runnable {
+
+        @Override
+        public void run() {
+            String thisThreadName = Thread.currentThread().getName();
+            List<Integer> partialResult = new ArrayList<>();
+            for (int i = 0; i < NUM_PARTIAL_RESULTS; i++) {
+                Integer num = random.nextInt(10);
+                System.out.println(thisThreadName + ": Crunching some numbers! Final result - " + num);
+                partialResult.add(num);
+            }
+            partialResults.add(partialResult);
+            try {
+                System.out.println(thisThreadName + " waiting for others to reach barrier.");
+                cyclicBarrier.await();
+            } catch (InterruptedException | BrokenBarrierException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+    class AggregatorThread implements Runnable {
+
+        @Override
+        public void run() {
+            String thisThreadName = Thread.currentThread().getName();
+            System.out.println(thisThreadName + ": Computing final sum of " + NUM_WORKERS + " workers, having " + NUM_PARTIAL_RESULTS + " results each.");
+            int sum = 0;
+            for (List<Integer> threadResult : partialResults) {
+                System.out.print("Adding ");
+                for (Integer partialResult : threadResult) {
+                    System.out.print(partialResult + " ");
+                    sum += partialResult;
+                }
+                System.out.println();
+            }
+            System.out.println(Thread.currentThread().getName() + ": Final result = " + sum);
+        }
+
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierDemo play = new CyclicBarrierDemo();
+        play.runSimulation(5, 3);
+    }
+
+}
@@ -0,0 +1,46 @@
+package com.baeldung.concurrent.cyclicbarrier;
+
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class CyclicBarrierResetExample {
+
+    private int count;
+    private int threadCount;
+    private final AtomicInteger updateCount;
+
+    CyclicBarrierResetExample(int count, int threadCount) {
+        updateCount = new AtomicInteger(0);
+        this.count = count;
+        this.threadCount = threadCount;
+    }
+
+    public int countWaits() {
+
+        CyclicBarrier cyclicBarrier = new CyclicBarrier(count);
+
+        ExecutorService es = Executors.newFixedThreadPool(threadCount);
+        for (int i = 0; i < threadCount; i++) {
+            es.execute(() -> {
+                try {
+                    if (cyclicBarrier.getNumberWaiting() > 0) {
+                        updateCount.incrementAndGet();
+                    }   
+                    cyclicBarrier.await();
+                } catch (InterruptedException | BrokenBarrierException e) {
+                    e.printStackTrace();
+                }
+            });
+        }
+        es.shutdown();
+        return updateCount.get();
+    }
+
+    public static void main(String[] args) {
+        CyclicBarrierResetExample ex = new CyclicBarrierResetExample(7, 20);
+        System.out.println("Count : " + ex.countWaits());
+    }
+}
@@ -0,0 +1,12 @@
+package com.baeldung.concurrent.daemon;
+
+public class MultipleThreadsExample {
+    public static void main(String[] args) {
+        NewThread t1 = new NewThread();
+        t1.setName("MyThread-1");
+        NewThread t2 = new NewThread();
+        t2.setName("MyThread-2");
+        t1.start();
+        t2.start();
+    }
+}
@@ -0,0 +1,23 @@
+package com.baeldung.concurrent.daemon;
+
+public class NewThread extends Thread {
+    public void run() {
+    	long startTime = System.currentTimeMillis();
+        while (true) {
+            for (int i = 0; i < 10; i++) {
+                System.out.println(this.getName() + ": New Thread is running..." + i);
+                try {
+                    //Wait for one sec so it doesn't print too fast
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+            // prevent the Thread to run forever. It will finish it's execution after 2 seconds
+            if (System.currentTimeMillis() - startTime > 2000) {
+            	Thread.currentThread().interrupt();
+            	break;
+            }
+        }
+    }
+}
@@ -0,0 +1,8 @@
+package com.baeldung.concurrent.daemon;
+
+public class SingleThreadExample {
+    public static void main(String[] args) {
+        NewThread t = new NewThread();
+        t.start();
+    }
+}
@@ -0,0 +1,29 @@
+package com.baeldung.concurrent.diningphilosophers;
+
+public class DiningPhilosophers {
+
+    public static void main(String[] args) throws Exception {
+
+        Philosopher[] philosophers = new Philosopher[5];
+        Object[] forks = new Object[philosophers.length];
+
+        for (int i = 0; i < forks.length; i++) {
+            forks[i] = new Object();
+        }
+
+        for (int i = 0; i < philosophers.length; i++) {
+
+            Object leftFork = forks[i];
+            Object rightFork = forks[(i + 1) % forks.length];
+
+            if (i == philosophers.length - 1) {
+                philosophers[i] = new Philosopher(rightFork, leftFork); // The last philosopher picks up the right fork first
+            } else {
+                philosophers[i] = new Philosopher(leftFork, rightFork);
+            }
+
+            Thread t = new Thread(philosophers[i], "Philosopher " + (i + 1));
+            t.start();
+        }
+    }
+}
@@ -0,0 +1,36 @@
+package com.baeldung.concurrent.diningphilosophers;
+
+public class Philosopher implements Runnable {
+
+    private final Object leftFork;
+    private final Object rightFork;
+
+    Philosopher(Object left, Object right) {
+        this.leftFork = left;
+        this.rightFork = right;
+    }
+
+    private void doAction(String action) throws InterruptedException {
+        System.out.println(Thread.currentThread().getName() + " " + action);
+        Thread.sleep(((int) (Math.random() * 100)));
+    }
+
+    @Override
+    public void run() {
+        try {
+            while (true) {
+                doAction(System.nanoTime() + ": Thinking"); // thinking
+                synchronized (leftFork) {
+                    doAction(System.nanoTime() + ": Picked up left fork");
+                    synchronized (rightFork) {
+                        doAction(System.nanoTime() + ": Picked up right fork - eating"); // eating
+                        doAction(System.nanoTime() + ": Put down right fork");
+                    }
+                    doAction(System.nanoTime() + ": Put down left fork. Returning to thinking");
+                }
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+    }
+}
@@ -0,0 +1,75 @@
+package com.baeldung.concurrent.evenandodd;
+
+import java.util.concurrent.Semaphore;
+
+public class PrintEvenOddSemaphore {
+
+    public static void main(String[] args) {
+        SharedPrinter sp = new SharedPrinter();
+        Thread odd = new Thread(new Odd(sp, 10), "Odd");
+        Thread even = new Thread(new Even(sp, 10), "Even");
+
+        odd.start();
+        even.start();
+    }
+}
+
+class SharedPrinter {
+
+    private final Semaphore semEven = new Semaphore(0);
+    private final Semaphore semOdd = new Semaphore(1);
+
+    void printEvenNum(int num) {
+        try {
+            semEven.acquire();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+        System.out.println(Thread.currentThread().getName() + ":"+num);
+        semOdd.release();
+    }
+
+    void printOddNum(int num) {
+        try {
+            semOdd.acquire();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+        System.out.println(Thread.currentThread().getName() + ":"+ num);
+        semEven.release();
+    }
+}
+
+class Even implements Runnable {
+    private final SharedPrinter sp;
+    private final int max;
+
+    Even(SharedPrinter sp, int max) {
+        this.sp = sp;
+        this.max = max;
+    }
+
+    @Override
+    public void run() {
+        for (int i = 2; i <= max; i = i + 2) {
+            sp.printEvenNum(i);
+        }
+    }
+}
+
+class Odd implements Runnable {
+    private SharedPrinter sp;
+    private int max;
+
+    Odd(SharedPrinter sp, int max) {
+        this.sp = sp;
+        this.max = max;
+    }
+
+    @Override
+    public void run() {
+        for (int i = 1; i <= max; i = i + 2) {
+            sp.printOddNum(i);
+        }
+    }
+}
@@ -0,0 +1,68 @@
+package com.baeldung.concurrent.evenandodd;
+
+public class PrintEvenOddWaitNotify {
+
+    public static void main(String... args) {
+        Printer print = new Printer();
+        Thread t1 = new Thread(new TaskEvenOdd(print, 10, false), "Odd");
+        Thread t2 = new Thread(new TaskEvenOdd(print, 10, true), "Even");
+        t1.start();
+        t2.start();
+    }
+}
+
+class TaskEvenOdd implements Runnable {
+    private final int max;
+    private final Printer print;
+    private final boolean isEvenNumber;
+
+    TaskEvenOdd(Printer print, int max, boolean isEvenNumber) {
+        this.print = print;
+        this.max = max;
+        this.isEvenNumber = isEvenNumber;
+    }
+
+    @Override
+    public void run() {
+        int number = isEvenNumber ? 2 : 1;
+        while (number <= max) {
+            if (isEvenNumber) {
+                print.printEven(number);
+            } else {
+                print.printOdd(number);
+            }
+            number += 2;
+        }
+    }
+}
+
+class Printer {
+    private volatile boolean isOdd;
+
+    synchronized void printEven(int number) {
+        while (!isOdd) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+        System.out.println(Thread.currentThread().getName() + ":" + number);
+        isOdd = false;
+        notify();
+    }
+
+    synchronized void printOdd(int number) {
+        while (isOdd) {
+            try {
+                wait();
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+        }
+        System.out.println(Thread.currentThread().getName() + ":" + number);
+        isOdd = true;
+        notify();
+    }
+
+}
@@ -0,0 +1,83 @@
+package com.baeldung.concurrent.locks;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Stack;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.ReentrantLock;
+
+import static java.lang.Thread.sleep;
+
+public class ReentrantLockWithCondition {
+
+    private static Logger LOG = LoggerFactory.getLogger(ReentrantLockWithCondition.class);
+
+    private Stack<String> stack = new Stack<>();
+    private static final int CAPACITY = 5;
+
+    private ReentrantLock lock = new ReentrantLock();
+    private Condition stackEmptyCondition = lock.newCondition();
+    private Condition stackFullCondition = lock.newCondition();
+
+    private void pushToStack(String item) throws InterruptedException {
+        try {
+            lock.lock();
+            if (stack.size() == CAPACITY) {
+                LOG.info(Thread.currentThread().getName() + " wait on stack full");
+                stackFullCondition.await();
+            }
+            LOG.info("Pushing the item " + item);
+            stack.push(item);
+            stackEmptyCondition.signalAll();
+        } finally {
+            lock.unlock();
+        }
+
+    }
+
+    private String popFromStack() throws InterruptedException {
+        try {
+            lock.lock();
+            if (stack.size() == 0) {
+                LOG.info(Thread.currentThread().getName() + " wait on stack empty");
+                stackEmptyCondition.await();
+            }
+            return stack.pop();
+        } finally {
+            stackFullCondition.signalAll();
+            lock.unlock();
+        }
+    }
+
+    public static void main(String[] args) {
+        final int threadCount = 2;
+        ReentrantLockWithCondition object = new ReentrantLockWithCondition();
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        service.execute(() -> {
+            for (int i = 0; i < 10; i++) {
+                try {
+                    object.pushToStack("Item " + i);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+
+        });
+
+        service.execute(() -> {
+            for (int i = 0; i < 10; i++) {
+                try {
+                    LOG.info("Item popped " + object.popFromStack());
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+
+        });
+
+        service.shutdown();
+    }
+}
@@ -0,0 +1,88 @@
+package com.baeldung.concurrent.locks;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReentrantLock;
+
+import static java.lang.Thread.sleep;
+
+public class SharedObjectWithLock {
+
+    private static final Logger LOG = LoggerFactory.getLogger(SharedObjectWithLock.class);
+
+    private ReentrantLock lock = new ReentrantLock(true);
+
+    private int counter = 0;
+
+    void perform() {
+
+        lock.lock();
+        LOG.info("Thread - " + Thread.currentThread().getName() + " acquired the lock");
+        try {
+            LOG.info("Thread - " + Thread.currentThread().getName() + " processing");
+            counter++;
+        } catch (Exception exception) {
+            LOG.error(" Interrupted Exception ", exception);
+        } finally {
+            lock.unlock();
+            LOG.info("Thread - " + Thread.currentThread().getName() + " released the lock");
+        }
+    }
+
+    private void performTryLock() {
+
+        LOG.info("Thread - " + Thread.currentThread().getName() + " attempting to acquire the lock");
+        try {
+            boolean isLockAcquired = lock.tryLock(2, TimeUnit.SECONDS);
+            if (isLockAcquired) {
+                try {
+                    LOG.info("Thread - " + Thread.currentThread().getName() + " acquired the lock");
+
+                    LOG.info("Thread - " + Thread.currentThread().getName() + " processing");
+                    sleep(1000);
+                } finally {
+                    lock.unlock();
+                    LOG.info("Thread - " + Thread.currentThread().getName() + " released the lock");
+
+                }
+            }
+        } catch (InterruptedException exception) {
+            LOG.error(" Interrupted Exception ", exception);
+        }
+        LOG.info("Thread - " + Thread.currentThread().getName() + " could not acquire the lock");
+    }
+
+    public ReentrantLock getLock() {
+        return lock;
+    }
+
+    boolean isLocked() {
+        return lock.isLocked();
+    }
+
+    boolean hasQueuedThreads() {
+        return lock.hasQueuedThreads();
+    }
+
+    int getCounter() {
+        return counter;
+    }
+
+    public static void main(String[] args) {
+
+        final int threadCount = 2;
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final SharedObjectWithLock object = new SharedObjectWithLock();
+
+        service.execute(object::perform);
+        service.execute(object::performTryLock);
+
+        service.shutdown();
+
+    }
+
+}
@@ -0,0 +1,104 @@
+package com.baeldung.concurrent.locks;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.StampedLock;
+
+import static java.lang.Thread.sleep;
+
+public class StampedLockDemo {
+    private Map<String, String> map = new HashMap<>();
+    private Logger logger = LoggerFactory.getLogger(StampedLockDemo.class);
+
+    private final StampedLock lock = new StampedLock();
+
+    public void put(String key, String value) throws InterruptedException {
+        long stamp = lock.writeLock();
+
+        try {
+            logger.info(Thread.currentThread().getName() + " acquired the write lock with stamp " + stamp);
+            map.put(key, value);
+        } finally {
+            lock.unlockWrite(stamp);
+            logger.info(Thread.currentThread().getName() + " unlocked the write lock with stamp " + stamp);
+        }
+    }
+
+    public String get(String key) throws InterruptedException {
+        long stamp = lock.readLock();
+        logger.info(Thread.currentThread().getName() + " acquired the read lock with stamp " + stamp);
+        try {
+            sleep(5000);
+            return map.get(key);
+
+        } finally {
+            lock.unlockRead(stamp);
+            logger.info(Thread.currentThread().getName() + " unlocked the read lock with stamp " + stamp);
+
+        }
+
+    }
+
+    private String readWithOptimisticLock(String key) throws InterruptedException {
+        long stamp = lock.tryOptimisticRead();
+        String value = map.get(key);
+
+        if (!lock.validate(stamp)) {
+            stamp = lock.readLock();
+            try {
+                sleep(5000);
+                return map.get(key);
+
+            } finally {
+                lock.unlock(stamp);
+                logger.info(Thread.currentThread().getName() + " unlocked the read lock with stamp " + stamp);
+
+            }
+        }
+        return value;
+    }
+
+    public static void main(String[] args) {
+        final int threadCount = 4;
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        StampedLockDemo object = new StampedLockDemo();
+
+        Runnable writeTask = () -> {
+
+            try {
+                object.put("key1", "value1");
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        };
+        Runnable readTask = () -> {
+
+            try {
+                object.get("key1");
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        };
+        Runnable readOptimisticTask = () -> {
+
+            try {
+                object.readWithOptimisticLock("key1");
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        };
+        service.submit(writeTask);
+        service.submit(writeTask);
+        service.submit(readTask);
+        service.submit(readOptimisticTask);
+
+        service.shutdown();
+
+    }
+
+}
@@ -0,0 +1,120 @@
+package com.baeldung.concurrent.locks;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import static java.lang.Thread.sleep;
+
+public class SynchronizedHashMapWithRWLock {
+
+    private static Map<String, String> syncHashMap = new HashMap<>();
+    private Logger logger = LoggerFactory.getLogger(SynchronizedHashMapWithRWLock.class);
+
+    private final ReadWriteLock lock = new ReentrantReadWriteLock();
+    private final Lock readLock = lock.readLock();
+    private final Lock writeLock = lock.writeLock();
+
+    public void put(String key, String value) throws InterruptedException {
+
+        try {
+            writeLock.lock();
+            logger.info(Thread.currentThread().getName() + " writing");
+            syncHashMap.put(key, value);
+            sleep(1000);
+        } finally {
+            writeLock.unlock();
+        }
+
+    }
+
+    public String get(String key) {
+        try {
+            readLock.lock();
+            logger.info(Thread.currentThread().getName() + " reading");
+            return syncHashMap.get(key);
+        } finally {
+            readLock.unlock();
+        }
+    }
+
+    public String remove(String key) {
+        try {
+            writeLock.lock();
+            return syncHashMap.remove(key);
+        } finally {
+            writeLock.unlock();
+        }
+    }
+
+    public boolean containsKey(String key) {
+        try {
+            readLock.lock();
+            return syncHashMap.containsKey(key);
+        } finally {
+            readLock.unlock();
+        }
+    }
+
+    boolean isReadLockAvailable() {
+        return readLock.tryLock();
+    }
+
+    public static void main(String[] args) throws InterruptedException {
+
+        final int threadCount = 3;
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        SynchronizedHashMapWithRWLock object = new SynchronizedHashMapWithRWLock();
+
+        service.execute(new Thread(new Writer(object), "Writer"));
+        service.execute(new Thread(new Reader(object), "Reader1"));
+        service.execute(new Thread(new Reader(object), "Reader2"));
+
+        service.shutdown();
+    }
+
+    private static class Reader implements Runnable {
+
+        SynchronizedHashMapWithRWLock object;
+
+        Reader(SynchronizedHashMapWithRWLock object) {
+            this.object = object;
+        }
+
+        @Override
+        public void run() {
+            for (int i = 0; i < 10; i++) {
+                object.get("key" + i);
+            }
+        }
+    }
+
+    private static class Writer implements Runnable {
+
+        SynchronizedHashMapWithRWLock object;
+
+        public Writer(SynchronizedHashMapWithRWLock object) {
+            this.object = object;
+        }
+
+        @Override
+        public void run() {
+            for (int i = 0; i < 10; i++) {
+                try {
+                    object.put("key" + i, "value" + i);
+                    sleep(1000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+
+}
@@ -0,0 +1,20 @@
+package com.baeldung.concurrent.parameter;
+
+import java.util.concurrent.Callable;
+import java.util.stream.IntStream;
+
+public class AverageCalculator implements Callable<Double> {
+
+    int[] numbers;
+
+    public AverageCalculator(int... parameter) {
+        this.numbers = parameter == null ? new int[0] : parameter;
+    }
+
+    @Override
+    public Double call() throws Exception {
+        return IntStream.of(this.numbers)
+            .average()
+            .orElse(0d);
+    }
+}
@@ -0,0 +1,32 @@
+package com.baeldung.concurrent.parameter;
+
+import java.util.concurrent.Callable;
+import java.util.stream.IntStream;
+
+public class ParameterizedThreadExample {
+
+    public static void parameterisedThreadAnonymousClass() {
+        final String parameter = "123";
+        Thread parameterizedThread = new Thread(new Runnable() {
+
+            @Override
+            public void run() {
+                System.out.println(Thread.currentThread()
+                    .getName() + " : " + parameter);
+            }
+        });
+
+        parameterizedThread.start();
+    }
+
+    public static Callable<Integer> sumCalculator(int... numbers) {
+        return () -> numbers != null ? IntStream.of(numbers)
+            .sum() : 0;
+    }
+
+    public static Callable<Double> averageCalculator(int... numbers) {
+        return () -> numbers != null ? IntStream.of(numbers)
+            .average()
+            .orElse(0d) : 0d;
+    }
+}
@@ -0,0 +1,27 @@
+package com.baeldung.concurrent.phaser;
+
+import java.util.concurrent.Phaser;
+
+class LongRunningAction implements Runnable {
+    private String threadName;
+    private Phaser ph;
+
+    LongRunningAction(String threadName, Phaser ph) {
+        this.threadName = threadName;
+        this.ph = ph;
+        ph.register();
+    }
+
+    @Override
+    public void run() {
+        System.out.println("This is phase " + ph.getPhase());
+        System.out.println("Thread " + threadName + " before long running action");
+        ph.arriveAndAwaitAdvance();
+        try {
+            Thread.sleep(20);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        ph.arriveAndDeregister();
+    }
+}
@@ -0,0 +1,25 @@
+package com.baeldung.concurrent.prioritytaskexecution;
+
+public class Job implements Runnable {
+    private String jobName;
+    private JobPriority jobPriority;
+    
+    public Job(String jobName, JobPriority jobPriority) {
+        this.jobName = jobName;
+        this.jobPriority = jobPriority != null ? jobPriority : JobPriority.MEDIUM;
+    }
+
+    public JobPriority getJobPriority() {
+        return jobPriority;
+    }
+
+    @Override
+    public void run() {
+        try {
+            System.out.println("Job:" + jobName + 
+              " Priority:" + jobPriority);
+            Thread.sleep(1000);
+        } catch (InterruptedException ignored) {
+        }
+    }
+}
--- a/Show More
+++ b/Show More