Merge branch 'master' into master

This commit is contained in:
iaforek
2017-08-28 09:09:59 +01:00
committed by GitHub
1006 changed files with 34360 additions and 4151 deletions
+11 -20
View File
@@ -23,7 +23,6 @@
- [Guide to Java Reflection](http://www.baeldung.com/java-reflection)
- [A Guide to Java Sockets](http://www.baeldung.com/a-guide-to-java-sockets)
- [Java 8 Collectors](http://www.baeldung.com/java-8-collectors)
- [Guide To CompletableFuture](http://www.baeldung.com/java-completablefuture)
- [Guide to Java 8s Functional Interfaces](http://www.baeldung.com/java-8-functional-interfaces)
- [Convert char to String in Java](http://www.baeldung.com/java-convert-char-to-string)
- [Random List Element](http://www.baeldung.com/java-random-list-element)
@@ -31,12 +30,10 @@
- [Java 8 Powerful Comparison with Lambdas](http://www.baeldung.com/java-8-sort-lambda)
- [Java Directory Size](http://www.baeldung.com/java-folder-size)
- [Java Try with Resources](http://www.baeldung.com/java-try-with-resources)
- [A Guide to the Java ExecutorService](http://www.baeldung.com/java-executor-service-tutorial)
- [Java 8 New Features](http://www.baeldung.com/java-8-new-features)
- [Lambda Expressions and Functional Interfaces: Tips and Best Practices](http://www.baeldung.com/java-8-lambda-expressions-tips)
- [The Double Colon Operator in Java 8](http://www.baeldung.com/java-8-double-colon-operator)
- [Java 8 Streams Advanced](http://www.baeldung.com/java-8-streams)
- [Introduction to Thread Pools in Java](http://www.baeldung.com/thread-pool-java-and-guava)
- [Introduction to Java 8 Streams](http://www.baeldung.com/java-8-streams-introduction)
- [Guide to the Fork/Join Framework in Java](http://www.baeldung.com/java-fork-join)
- [How to Print Screen in Java](http://www.baeldung.com/print-screen-in-java)
@@ -57,18 +54,11 @@
- [The Basics of Java Generics](http://www.baeldung.com/java-generics)
- [The Traveling Salesman Problem in Java](http://www.baeldung.com/java-simulated-annealing-for-traveling-salesman)
- [How to Create an Executable JAR with Maven](http://www.baeldung.com/executable-jar-with-maven)
- [Guide to java.util.concurrent.Future](http://www.baeldung.com/java-future)
- [Guide to java.util.concurrent.BlockingQueue](http://www.baeldung.com/java-blocking-queue)
- [Guide to CountDownLatch in Java](http://www.baeldung.com/java-countdown-latch)
- [How to Design a Genetic Algorithm in Java](http://www.baeldung.com/java-genetic-algorithm)
- [A Guide to ConcurrentMap](http://www.baeldung.com/java-concurrent-map)
- [Guide to PriorityBlockingQueue in Java](http://www.baeldung.com/java-priority-blocking-queue)
- [Guide to Java 8 groupingBy Collector](http://www.baeldung.com/java-groupingby-collector)
- [Avoiding the ConcurrentModificationException in Java](http://www.baeldung.com/java-concurrentmodificationexception)
- [Guide to WeakHashMap in Java](http://www.baeldung.com/java-weakhashmap)
- [Strategy Design Pattern in Java 8](http://www.baeldung.com/java-strategy-pattern)
- [Java 8 and Infinite Streams](http://www.baeldung.com/java-inifinite-streams)
- [Custom Thread Pools In Java 8 Parallel Streams](http://www.baeldung.com/java-8-parallel-streams-custom-threadpool)
- [String Operations with Java Streams](http://www.baeldung.com/java-stream-operations-on-strings)
- [Spring Security Cache Control Headers](http://www.baeldung.com/spring-security-cache-control-headers)
- [Basic Introduction to JMX](http://www.baeldung.com/java-management-extensions)
@@ -91,7 +81,6 @@
- [Avoiding ConcurrentModificationException when iterating and removing](http://www.baeldung.com/avoiding-concurrentmodificationexception-when-iterating-and-removing)
- [Removing all nulls from a List in Java](http://www.baeldung.com/java-remove-nulls-from-list)
- [Removing all duplicates from a List in Java](http://www.baeldung.com/java-remove-duplicates-from-list)
- [An Introduction to ThreadLocal in Java](http://www.baeldung.com/java-threadlocal)
- [Using Math.pow in Java](http://www.baeldung.com/java-math-pow)
- [Converting Strings to Enums in Java](http://www.baeldung.com/java-string-to-enum)
- [Flattening Nested Collections in Java](http://www.baeldung.com/java-flatten-nested-collections)
@@ -101,33 +90,35 @@
- [HashSet and TreeSet Comparison](http://www.baeldung.com/java-hashset-vs-treeset)
- [How to Perform a Simple HTTP Request in Java](http://www.baeldung.com/java-http-request)
- [Call Methods at Runtime Using Java Reflection](http://www.baeldung.com/java-method-reflection)
- [Guide to DelayQueue](http://www.baeldung.com/java-delay-queue)
- [Guide to UUID in JAVA](http://www.baeldung.com/guide-to-uuid-in-java)
- [Comparing getPath(), getAbsolutePath(), and getCanonicalPath() in Java](http://www.baeldung.com/java-path)
- [How to Add a Single Element to a Stream](http://www.baeldung.com/java-stream-append-prepend)
- [Iterating Over Enum Values in Java](http://www.baeldung.com/java-enum-iteration)
- [A Guide to Java SynchronousQueue](http://www.baeldung.com/java-synchronous-queue)
- [Guide to the Java TransferQueue](http://www.baeldung.com/java-transfer-queue)
- [Kotlin Java Interoperability](http://www.baeldung.com/kotlin-java-interoperability)
- [Guide to the ConcurrentSkipListMap](http://www.baeldung.com/java-concurrent-skip-list-map)
- [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)
- [Using Java MappedByteBuffer](http://www.baeldung.com/java-mapped-byte-buffer)
- [The Difference Between map() and flatMap()](http://www.baeldung.com/java-difference-map-and-flatmap)
- [How to Round a Number to N Decimal Places in Java](http://www.baeldung.com/java-round-decimal-number)
- [Changing Annotation Parameters At Runtime](http://www.baeldung.com/java-reflection-change-annotation-params)
- [How to Find all Getters Returning Null](http://www.baeldung.com/java-getters-returning-null)
- [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
- [Changing the Order in a Sum Operation Can Produce Different Results?](http://www.baeldung.com/java-floating-point-sum-order)
- [How to Get a Name of a Method Being Executed?](http://www.baeldung.com/java-name-of-executing-method)
- [Iterate over a Map in Java](http://www.baeldung.com/java-iterate-map)
- [Dynamic Proxies in Java](http://www.baeldung.com/java-dynamic-proxies)
- [How to Copy an Array in Java](http://www.baeldung.com/java-array-copy)
- [Introduction to JDBC](http://www.baeldung.com/java-jdbc)
- [Guide to CopyOnWriteArrayList](http://www.baeldung.com/java-copy-on-write-arraylist)
- [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
- [Converting a Stack Trace to a String in Java](http://www.baeldung.com/java-stacktrace-to-string)
- [Guide to the Java Phaser](http://www.baeldung.com/java-phaser)
- [Count Occurrences of a Char in a String](http://www.baeldung.com/java-count-chars)
- [Java Double Brace Initialization](http://www.baeldung.com/java-double-brace-initialization)
- [The StackOverflowError in Java](http://www.baeldung.com/java-stack-overflow-error)
- [Split a String in Java](http://www.baeldung.com/java-split-string)
- [Introduction to Java Serialization](http://www.baeldung.com/java-serialization)
- [How to Remove the Last Character of a String?](http://www.baeldung.com/java-remove-last-character-of-string)
- [Guide to Synchronized Keyword in Java](http://www.baeldung.com/java-synchronized)
- [ClassNotFoundException vs NoClassDefFoundError](http://www.baeldung.com/java-classnotfoundexception-and-noclassdeffounderror)
- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
- [How to Get the Last Element of a Stream in Java?](http://www.baeldung.com/java-stream-last-element)
- [Guide to Escaping Characters in Java RegExps](http://www.baeldung.com/java-regexp-escape-char)
- [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
- [Introduction to the Java 8 Date/Time API](http://www.baeldung.com/java-8-date-time-intro)
- [Migrating to the New Java 8 Date Time API](http://www.baeldung.com/migrating-to-java-8-date-time-api)
+22 -6
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@@ -80,7 +80,11 @@
</dependency>
<!-- logging -->
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
@@ -182,6 +186,16 @@
<artifactId>fscontext</artifactId>
<version>${fscontext.version}</version>
</dependency>
<dependency>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
<version>${joda-time.version}</version>
</dependency>
<dependency>
<groupId>com.darwinsys</groupId>
<artifactId>hirondelle-date4j</artifactId>
<version>${hirondelle-date4j.version}</version>
</dependency>
</dependencies>
<build>
@@ -382,7 +396,7 @@
</profile>
</profiles>
<properties>
<properties>
<!-- marshalling -->
<jackson.version>2.8.5</jackson.version>
@@ -391,7 +405,7 @@
<logback.version>1.1.7</logback.version>
<!-- util -->
<guava.version>21.0</guava.version>
<guava.version>22.0</guava.version>
<commons-lang3.version>3.5</commons-lang3.version>
<bouncycastle.version>1.55</bouncycastle.version>
<commons-codec.version>1.10</commons-codec.version>
@@ -404,17 +418,19 @@
<grep4j.version>1.8.7</grep4j.version>
<lombok.version>1.16.12</lombok.version>
<fscontext.version>4.6-b01</fscontext.version>
<joda-time.version>2.9.9</joda-time.version>
<hirondelle-date4j.version>1.5.1</hirondelle-date4j.version>
<!-- testing -->
<org.hamcrest.version>1.3</org.hamcrest.version>
<junit.version>4.12</junit.version>
<mockito.version>1.10.19</mockito.version>
<mockito.version>2.8.9</mockito.version>
<assertj.version>3.6.1</assertj.version>
<avaitility.version>1.7.0</avaitility.version>
<!-- maven plugins -->
<maven-compiler-plugin.version>3.6.0</maven-compiler-plugin.version>
<maven-surefire-plugin.version>2.19.1</maven-surefire-plugin.version>
</properties>
</project>
</project>
@@ -1,24 +0,0 @@
package com.baeldung.concurrent.blockingqueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
public class BlockingQueueUsage {
public static void main(String[] args) {
int BOUND = 10;
int N_PRODUCERS = 4;
int N_CONSUMERS = Runtime.getRuntime().availableProcessors();
int poisonPill = Integer.MAX_VALUE;
int poisonPillPerProducer = N_CONSUMERS / N_PRODUCERS;
BlockingQueue<Integer> queue = new LinkedBlockingQueue<>(BOUND);
for (int i = 0; i < N_PRODUCERS; i++) {
new Thread(new NumbersProducer(queue, poisonPill, poisonPillPerProducer)).start();
}
for (int j = 0; j < N_CONSUMERS; j++) {
new Thread(new NumbersConsumer(queue, poisonPill)).start();
}
}
}
@@ -1,28 +0,0 @@
package com.baeldung.concurrent.blockingqueue;
import java.util.concurrent.BlockingQueue;
public class NumbersConsumer implements Runnable {
private final BlockingQueue<Integer> queue;
private final int poisonPill;
NumbersConsumer(BlockingQueue<Integer> queue, int poisonPill) {
this.queue = queue;
this.poisonPill = poisonPill;
}
public void run() {
try {
while (true) {
Integer number = queue.take();
if (number.equals(poisonPill)) {
return;
}
String result = number.toString();
System.out.println(Thread.currentThread().getName() + " result: " + result);
}
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
}
@@ -1,34 +0,0 @@
package com.baeldung.concurrent.blockingqueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ThreadLocalRandom;
public class NumbersProducer implements Runnable {
private final BlockingQueue<Integer> numbersQueue;
private final int poisonPill;
private final int poisonPillPerProducer;
NumbersProducer(BlockingQueue<Integer> numbersQueue, int poisonPill, int poisonPillPerProducer) {
this.numbersQueue = numbersQueue;
this.poisonPill = poisonPill;
this.poisonPillPerProducer = poisonPillPerProducer;
}
public void run() {
try {
generateNumbers();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
}
private void generateNumbers() throws InterruptedException {
for (int i = 0; i < 100; i++) {
numbersQueue.put(ThreadLocalRandom.current().nextInt(100));
}
for (int j = 0; j < poisonPillPerProducer; j++) {
numbersQueue.put(poisonPill);
}
}
}
@@ -1,23 +0,0 @@
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");
}
}
@@ -1,34 +0,0 @@
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();
}
}
}
@@ -1,22 +0,0 @@
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();
}
}
@@ -1,81 +0,0 @@
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);
}
}
@@ -1,35 +0,0 @@
package com.baeldung.concurrent.delayqueue;
import com.google.common.primitives.Ints;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;
public class DelayObject implements Delayed {
private String data;
private long startTime;
DelayObject(String data, long delayInMilliseconds) {
this.data = data;
this.startTime = System.currentTimeMillis() + delayInMilliseconds;
}
@Override
public long getDelay(TimeUnit unit) {
long diff = startTime - System.currentTimeMillis();
return unit.convert(diff, TimeUnit.MILLISECONDS);
}
@Override
public int compareTo(Delayed o) {
return Ints.saturatedCast(this.startTime - ((DelayObject) o).startTime);
}
@Override
public String toString() {
return "{" +
"data='" + data + '\'' +
", startTime=" + startTime +
'}';
}
}
@@ -1,30 +0,0 @@
package com.baeldung.concurrent.delayqueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.atomic.AtomicInteger;
public class DelayQueueConsumer implements Runnable {
private BlockingQueue<DelayObject> queue;
private final Integer numberOfElementsToTake;
final AtomicInteger numberOfConsumedElements = new AtomicInteger();
DelayQueueConsumer(BlockingQueue<DelayObject> queue, Integer numberOfElementsToTake) {
this.queue = queue;
this.numberOfElementsToTake = numberOfElementsToTake;
}
@Override
public void run() {
for (int i = 0; i < numberOfElementsToTake; i++) {
try {
DelayObject object = queue.take();
numberOfConsumedElements.incrementAndGet();
System.out.println("Consumer take: " + object);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
@@ -1,34 +0,0 @@
package com.baeldung.concurrent.delayqueue;
import java.util.UUID;
import java.util.concurrent.BlockingQueue;
public class DelayQueueProducer implements Runnable {
private BlockingQueue<DelayObject> queue;
private final Integer numberOfElementsToProduce;
private final Integer delayOfEachProducedMessageMilliseconds;
DelayQueueProducer(BlockingQueue<DelayObject> queue,
Integer numberOfElementsToProduce,
Integer delayOfEachProducedMessageMilliseconds) {
this.queue = queue;
this.numberOfElementsToProduce = numberOfElementsToProduce;
this.delayOfEachProducedMessageMilliseconds = delayOfEachProducedMessageMilliseconds;
}
@Override
public void run() {
for (int i = 0; i < numberOfElementsToProduce; i++) {
DelayObject object
= new DelayObject(UUID.randomUUID().toString(), delayOfEachProducedMessageMilliseconds);
System.out.println("Put object = " + object);
try {
queue.put(object);
Thread.sleep(500);
} catch (InterruptedException ie) {
ie.printStackTrace();
}
}
}
}
@@ -1,29 +0,0 @@
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();
}
}
}
@@ -1,35 +0,0 @@
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();
}
}
}
@@ -1,26 +0,0 @@
package com.baeldung.concurrent.future;
import java.util.concurrent.RecursiveTask;
public class FactorialSquareCalculator extends RecursiveTask<Integer> {
private static final long serialVersionUID = 1L;
final private Integer n;
FactorialSquareCalculator(Integer n) {
this.n = n;
}
@Override
protected Integer compute() {
if (n <= 1) {
return n;
}
FactorialSquareCalculator calculator = new FactorialSquareCalculator(n - 1);
calculator.fork();
return n * n + calculator.join();
}
}
@@ -1,20 +0,0 @@
package com.baeldung.concurrent.future;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
class SquareCalculator {
private final ExecutorService executor;
SquareCalculator(ExecutorService executor) {
this.executor = executor;
}
Future<Integer> calculate(Integer input) {
return executor.submit(() -> {
Thread.sleep(1000);
return input * input;
});
}
}
@@ -1,83 +0,0 @@
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();
}
}
@@ -1,88 +0,0 @@
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();
}
}
@@ -1,104 +0,0 @@
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();
}
}
@@ -1,120 +0,0 @@
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();
}
}
}
}
}
@@ -1,27 +0,0 @@
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();
}
}
@@ -1,31 +0,0 @@
package com.baeldung.concurrent.semaphores;
import java.util.concurrent.Semaphore;
class CounterUsingMutex {
private final Semaphore mutex;
private int count;
CounterUsingMutex() {
mutex = new Semaphore(1);
count = 0;
}
void increase() throws InterruptedException {
mutex.acquire();
this.count = this.count + 1;
Thread.sleep(1000);
mutex.release();
}
int getCount() {
return this.count;
}
boolean hasQueuedThreads() {
return mutex.hasQueuedThreads();
}
}
@@ -1,23 +0,0 @@
package com.baeldung.concurrent.semaphores;
import java.util.concurrent.TimeUnit;
import org.apache.commons.lang3.concurrent.TimedSemaphore;
class DelayQueueUsingTimedSemaphore {
private final TimedSemaphore semaphore;
DelayQueueUsingTimedSemaphore(long period, int slotLimit) {
semaphore = new TimedSemaphore(period, TimeUnit.SECONDS, slotLimit);
}
boolean tryAdd() {
return semaphore.tryAcquire();
}
int availableSlots() {
return semaphore.getAvailablePermits();
}
}
@@ -1,25 +0,0 @@
package com.baeldung.concurrent.semaphores;
import java.util.concurrent.Semaphore;
class LoginQueueUsingSemaphore {
private final Semaphore semaphore;
LoginQueueUsingSemaphore(int slotLimit) {
semaphore = new Semaphore(slotLimit);
}
boolean tryLogin() {
return semaphore.tryAcquire();
}
void logout() {
semaphore.release();
}
int availableSlots() {
return semaphore.availablePermits();
}
}
@@ -1,21 +0,0 @@
package com.baeldung.concurrent.skiplist;
import java.time.ZonedDateTime;
class Event {
private final ZonedDateTime eventTime;
private final String content;
Event(ZonedDateTime eventTime, String content) {
this.eventTime = eventTime;
this.content = content;
}
ZonedDateTime getEventTime() {
return eventTime;
}
String getContent() {
return content;
}
}
@@ -1,29 +0,0 @@
package com.baeldung.concurrent.skiplist;
import java.time.ZonedDateTime;
import java.util.Comparator;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
class EventWindowSort {
private final ConcurrentSkipListMap<ZonedDateTime, String> events
= new ConcurrentSkipListMap<>(Comparator.comparingLong(value -> value.toInstant().toEpochMilli()));
void acceptEvent(Event event) {
events.put(event.getEventTime(), event.getContent());
}
ConcurrentNavigableMap<ZonedDateTime, String> getEventsFromLastMinute() {
return events.tailMap(ZonedDateTime
.now()
.minusMinutes(1));
}
ConcurrentNavigableMap<ZonedDateTime, String> getEventsOlderThatOneMinute() {
return events.headMap(ZonedDateTime
.now()
.minusMinutes(1));
}
}
@@ -1,27 +0,0 @@
package com.baeldung.concurrent.sleepwait;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/***
* Example of waking up a waiting thread
*/
public class ThreadA {
private static final Logger LOG = LoggerFactory.getLogger(ThreadA.class);
private static final ThreadB b = new ThreadB();
public static void main(String... args) throws InterruptedException {
b.start();
synchronized (b) {
while (b.sum == 0) {
LOG.debug("Waiting for ThreadB to complete...");
b.wait();
}
LOG.debug("ThreadB has completed. Sum from that thread is: " + b.sum);
}
}
}
@@ -1,20 +0,0 @@
package com.baeldung.concurrent.sleepwait;
/***
* Example of waking up a waiting thread
*/
class ThreadB extends Thread {
int sum;
@Override
public void run() {
synchronized (this) {
int i = 0;
while (i < 100000) {
sum += i;
i++;
}
notify();
}
}
}
@@ -1,29 +0,0 @@
package com.baeldung.concurrent.sleepwait;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/***
* Example of wait() and sleep() methods
*/
public class WaitSleepExample {
private static final Logger LOG = LoggerFactory.getLogger(WaitSleepExample.class);
private static final Object LOCK = new Object();
public static void main(String... args) throws InterruptedException {
sleepWaitInSynchronizedBlocks();
}
private static void sleepWaitInSynchronizedBlocks() throws InterruptedException {
Thread.sleep(1000); // called on the thread
LOG.debug("Thread '" + Thread.currentThread().getName() + "' is woken after sleeping for 1 second");
synchronized (LOCK) {
LOCK.wait(1000); // called on the object, synchronization required
LOG.debug("Object '" + LOCK + "' is woken after waiting for 1 second");
}
}
}
@@ -1,35 +0,0 @@
package com.baeldung.concurrent.synchronize;
public class BaeldungSynchronizedBlocks {
private int count = 0;
private static int staticCount = 0;
void performSynchronisedTask() {
synchronized (this) {
setCount(getCount() + 1);
}
}
static void performStaticSyncTask() {
synchronized (BaeldungSynchronizedBlocks.class) {
setStaticCount(getStaticCount() + 1);
}
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
static int getStaticCount() {
return staticCount;
}
private static void setStaticCount(int staticCount) {
BaeldungSynchronizedBlocks.staticCount = staticCount;
}
}
@@ -1,37 +0,0 @@
package com.baeldung.concurrent.synchronize;
public class BaeldungSynchronizedMethods {
private int sum = 0;
private int syncSum = 0;
static int staticSum = 0;
void calculate() {
setSum(getSum() + 1);
}
synchronized void synchronisedCalculate() {
setSyncSum(getSyncSum() + 1);
}
static synchronized void syncStaticCalculate() {
staticSum = staticSum + 1;
}
public int getSum() {
return sum;
}
public void setSum(int sum) {
this.sum = sum;
}
int getSyncSum() {
return syncSum;
}
private void setSyncSum(int syncSum) {
this.syncSum = syncSum;
}
}
@@ -4,12 +4,12 @@ import java.io.Serializable;
public class AppleProduct implements Serializable {
private static final long serialVersionUID = 1234567L; // user-defined (i.e. not default or generated)
// private static final long serialVersionUID = 7654321L; // user-defined (i.e. not default or generated)
private static final long serialVersionUID = 1234567L; // user-defined (i.e. not default or generated)
// private static final long serialVersionUID = 7654321L; // user-defined (i.e. not default or generated)
public String headphonePort;
public String thunderboltPort;
public String lighteningPort;
public String lightningPort;
public String getHeadphonePort() {
return headphonePort;
@@ -23,4 +23,8 @@ public class AppleProduct implements Serializable {
return serialVersionUID;
}
public String getLightningPort() {
return lightningPort;
}
}
@@ -9,11 +9,12 @@ public class DeserializationUtility {
public static void main(String[] args) throws ClassNotFoundException, IOException {
String serializedObj = "rO0ABXNyACljb20uYmFlbGR1bmcuZGVzZXJpYWxpemF0aW9uLkFwcGxlUHJvZHVjdAAAAAAAEtaHAgADTAANaGVhZHBob25lUG9ydHQAEkxqYXZhL2xhbmcvU3RyaW5nO0wADmxpZ2h0ZW5pbmdQb3J0cQB+AAFMAA90aHVuZGVyYm9sdFBvcnRxAH4AAXhwdAARaGVhZHBob25lUG9ydDIwMjBwdAATdGh1bmRlcmJvbHRQb3J0MjAyMA==";
String serializedObj = "rO0ABXNyACljb20uYmFlbGR1bmcuZGVzZXJpYWxpemF0aW9uLkFwcGxlUHJvZHVjdAAAAAAAEtaHAgADTAANaGVhZHBob25lUG9ydHQAEkxqYXZhL2xhbmcvU3RyaW5nO0wADWxpZ2h0bmluZ1BvcnRxAH4AAUwAD3RodW5kZXJib2x0UG9ydHEAfgABeHB0ABFoZWFkcGhvbmVQb3J0MjAyMHQAEWxpZ2h0bmluZ1BvcnQyMDIwdAATdGh1bmRlcmJvbHRQb3J0MjAyMA==";
System.out.println("Deserializing AppleProduct...");
AppleProduct deserializedObj = (AppleProduct) deSerializeObjectFromString(serializedObj);
System.out.println("Headphone port of AppleProduct:" + deserializedObj.getHeadphonePort());
System.out.println("Thunderbolt port of AppleProduct:" + deserializedObj.getThunderboltPort());
System.out.println("LightningPort port of AppleProduct:" + deserializedObj.getLightningPort());
}
public static Object deSerializeObjectFromString(String s) throws IOException, ClassNotFoundException {
@@ -13,6 +13,7 @@ public class SerializationUtility {
AppleProduct macBook = new AppleProduct();
macBook.headphonePort = "headphonePort2020";
macBook.thunderboltPort = "thunderboltPort2020";
macBook.lightningPort = "lightningPort2020";
String serializedObj = serializeObjectToString(macBook);
System.out.println("Serialized AppleProduct object to string:");
@@ -0,0 +1,13 @@
package com.baeldung.designpatterns.adapter;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class AdapterPatternDriver {
public static void main(String args[]) {
LuxuryCarsSpeedAdapter luxuryCars = new LuxuryCarsSpeedAdapterImpl();
LOG.info("Bugatti Veyron Super Sport's top speed is " + luxuryCars.bugattiVeyronInKMPH() + " Kmph.");
LOG.info("McLaren F1 top speed is " + luxuryCars.mcLarenInKMPH() + " Kmph.");
LOG.info("Aston Martin One-77 top speed is " + luxuryCars.astonMartinInKMPH() + " Kmph.");
}
}
@@ -0,0 +1,15 @@
package com.baeldung.designpatterns.adapter;
public class LuxuryCarsSpeed {
public double bugattiVeyronInMPH() {
return 268;
}
public double mcLarenInMPH() {
return 241;
}
public double astonMartinInMPH() {
return 220;
}
}
@@ -0,0 +1,9 @@
package com.baeldung.designpatterns.adapter;
public interface LuxuryCarsSpeedAdapter {
public double bugattiVeyronInKMPH();
public double mcLarenInKMPH();
public double astonMartinInKMPH();
}
@@ -0,0 +1,26 @@
package com.baeldung.designpatterns.adapter;
public class LuxuryCarsSpeedAdapterImpl extends LuxuryCarsSpeed implements LuxuryCarsSpeedAdapter {
@Override
public double bugattiVeyronInKMPH() {
double mph = super.bugattiVeyronInMPH();
return convertMPHtoKMPH(mph);
}
@Override
public double mcLarenInKMPH() {
double mph = super.mcLarenInMPH();
return convertMPHtoKMPH(mph);
}
@Override
public double astonMartinInKMPH() {
double mph = super.astonMartinInMPH();
return convertMPHtoKMPH(mph);
}
private double convertMPHtoKMPH(double mph) {
return mph * 1.60934;
}
}
@@ -0,0 +1,12 @@
package com.baeldung.designpatterns.bridge;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class Blue implements Color {
@Override
public void fillColor() {
LOG.info("Color : Blue");
}
}
@@ -0,0 +1,14 @@
package com.baeldung.designpatterns.bridge;
public class BridgePatternDriver {
public static void main(String[] args) {
//a square with red color
Shape square = new Square(new Red());
square.drawShape();
//a triangle with blue color
Shape triangle = new Triangle(new Blue());
triangle.drawShape();
}
}
@@ -0,0 +1,5 @@
package com.baeldung.designpatterns.bridge;
public interface Color {
public void fillColor();
}
@@ -0,0 +1,12 @@
package com.baeldung.designpatterns.bridge;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class Red implements Color {
@Override
public void fillColor() {
LOG.info("Color : Red");
}
}
@@ -0,0 +1,11 @@
package com.baeldung.designpatterns.bridge;
public abstract class Shape {
protected Color color;
public Shape(Color color) {
this.color = color;
}
abstract public void drawShape();
}
@@ -0,0 +1,16 @@
package com.baeldung.designpatterns.bridge;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class Square extends Shape {
public Square(Color color) {
super(color);
}
@Override
public void drawShape() {
LOG.info("Square drawn. ");
color.fillColor();
}
}
@@ -0,0 +1,16 @@
package com.baeldung.designpatterns.bridge;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class Triangle extends Shape {
public Triangle(Color color) {
super(color);
}
@Override
public void drawShape() {
LOG.info("Triangle drawn. ");
color.fillColor();
}
}
@@ -0,0 +1,16 @@
package com.baeldung.designpatterns.decorator;
public class BubbleLights extends TreeDecorator {
public BubbleLights(ChristmasTree tree) {
super(tree);
}
public String decorate() {
return super.decorate() + decorateWithBubbleLights();
}
private String decorateWithBubbleLights() {
return " with Bubble Lights";
}
}
@@ -0,0 +1,5 @@
package com.baeldung.designpatterns.decorator;
public interface ChristmasTree {
public String decorate();
}
@@ -0,0 +1,10 @@
package com.baeldung.designpatterns.decorator;
public class ChristmasTreeImpl implements ChristmasTree {
@Override
public String decorate() {
return "Christmas tree";
}
}
@@ -0,0 +1,18 @@
package com.baeldung.designpatterns.decorator;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class DecoratorPatternDriver {
public static void main(String[] args) {
// christmas tree with just one Garland
ChristmasTree tree1 = new Garland(new ChristmasTreeImpl());
LOG.info(tree1.decorate());
// christmas tree with two Garlands and one Bubble lights
ChristmasTree tree2 = new BubbleLights(new Garland(new Garland(new ChristmasTreeImpl())));
LOG.info(tree2.decorate());
}
}
@@ -0,0 +1,16 @@
package com.baeldung.designpatterns.decorator;
public class Garland extends TreeDecorator {
public Garland(ChristmasTree tree) {
super(tree);
}
public String decorate() {
return super.decorate() + decorateWithGarland();
}
private String decorateWithGarland() {
return " with Garland";
}
}
@@ -0,0 +1,15 @@
package com.baeldung.designpatterns.decorator;
public abstract class TreeDecorator implements ChristmasTree {
private ChristmasTree tree;
public TreeDecorator(ChristmasTree tree) {
this.tree = tree;
}
@Override
public String decorate() {
return tree.decorate();
}
}
@@ -0,0 +1,5 @@
package com.baeldung.designpatterns.proxy;
public interface ExpensiveObject {
public void process();
}
@@ -0,0 +1,20 @@
package com.baeldung.designpatterns.proxy;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;;
public class ExpensiveObjectImpl implements ExpensiveObject {
public ExpensiveObjectImpl() {
heavyInitialConfiguration();
}
@Override
public void process() {
LOG.info("processing complete.");
}
private void heavyInitialConfiguration() {
LOG.info("Loading initial configuration...");
}
}
@@ -0,0 +1,13 @@
package com.baeldung.designpatterns.proxy;
public class ExpensiveObjectProxy implements ExpensiveObject{
private static ExpensiveObject object;
@Override
public void process() {
if(object == null) {
object = new ExpensiveObjectImpl();
}
object.process();
}
}
@@ -0,0 +1,9 @@
package com.baeldung.designpatterns.proxy;
public class ProxyPatternDriver {
public static void main(String[] args) {
ExpensiveObject object = new ExpensiveObjectProxy();
object.process();
object.process();
}
}
@@ -0,0 +1,28 @@
package com.baeldung.designpatterns.singleton;
public class ClassSingleton {
private static ClassSingleton INSTANCE;
private String info = "Initial class info";
private ClassSingleton(){
}
public static ClassSingleton getInstance(){
if(INSTANCE == null){
INSTANCE = new ClassSingleton();
}
return INSTANCE;
}
// getters and setters
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
}
@@ -0,0 +1,26 @@
package com.baeldung.designpatterns.singleton;
public enum EnumSingleton {
INSTANCE("Initial enum info"); //Name of the single instance
private String info;
private EnumSingleton(String info) {
this.info = info;
}
public EnumSingleton getInstance(){
return INSTANCE;
}
//getters and setters
public String getInfo() {
return info;
}
public void setInfo(String info) {
this.info = info;
}
}
@@ -0,0 +1,32 @@
package com.baeldung.designpatterns.singleton;
public class Sandbox {
public static void main(String[] args) {
//Class singleton
ClassSingleton classSingleton1 = ClassSingleton.getInstance();
//OurSingleton object1 = new OurSingleton(); // The constructor OurSingleton() is not visible
System.out.println(classSingleton1.getInfo()); //Initial class info
ClassSingleton classSingleton2 = ClassSingleton.getInstance();
classSingleton2.setInfo("New class info");
System.out.println(classSingleton1.getInfo()); //New class info
System.out.println(classSingleton2.getInfo()); //New class info
//Enum singleton
EnumSingleton enumSingleton1 = EnumSingleton.INSTANCE.getInstance();
System.out.println(enumSingleton1.getInfo()); //Initial enum info
EnumSingleton enumSingleton2 = EnumSingleton.INSTANCE.getInstance();
enumSingleton2.setInfo("New enum info");
System.out.println(enumSingleton1.getInfo()); //New enum info
System.out.println(enumSingleton2.getInfo()); //New enum info
}
}
@@ -0,0 +1,35 @@
package com.baeldung.designpatterns.util;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Properties;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
public class LogerUtil {
public final static Logger LOG = Logger.getLogger("GLOBAL");
static {
configuration();
}
private static void configuration() {
Properties props = new Properties();
try {
props.load(
new BufferedReader(
new InputStreamReader(
LogerUtil.class.getResourceAsStream("/log4jstructuraldp.properties")
)
)
);
} catch (IOException e) {
System.out.println("log4jstructuraldp.properties file not configured properly");
System.exit(0);
}
PropertyConfigurator.configure(props);
}
}
@@ -14,26 +14,25 @@ public class LookupFSJNDI {
super();
init();
}
private void init() throws NamingException {
Hashtable<String, String> env = new Hashtable<String, String>();
env.put (Context.INITIAL_CONTEXT_FACTORY,
"com.sun.jndi.fscontext.RefFSContextFactory");
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
// URI to namespace (actual directory)
env.put(Context.PROVIDER_URL, "file:./src/test/resources");
ctx = new InitialContext(env);
}
public InitialContext getCtx() {
return ctx;
}
public File getFile(String fileName) {
File file;
try {
file = (File)getCtx().lookup(fileName);
file = (File) getCtx().lookup(fileName);
} catch (NamingException e) {
file = null;
}
@@ -43,6 +43,7 @@ public class CustomRecursiveAction extends RecursiveAction {
private void processing(String work) {
String result = work.toUpperCase();
logger.info("This result - (" + result + ") - was processed by " + Thread.currentThread().getName());
logger.info("This result - (" + result + ") - was processed by " + Thread.currentThread()
.getName());
}
}
@@ -0,0 +1,41 @@
package com.baeldung.hashcode.entities;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class User {
private final Logger logger = LoggerFactory.getLogger(User.class);
private long id;
private String name;
private String email;
public User(long id, String name, String email) {
this.id = id;
this.name = name;
this.email = email;
}
@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null)
return false;
if (this.getClass() != o.getClass())
return false;
User user = (User) o;
return id != user.id && (!name.equals(user.name) && !email.equals(user.email));
}
@Override
public int hashCode() {
int hash = 7;
hash = 31 * hash + (int) id;
hash = 31 * hash + (name == null ? 0 : name.hashCode());
hash = 31 * hash + (email == null ? 0 : email.hashCode());
logger.info("hashCode() method called - Computed hash: " + hash);
return hash;
}
// getters and setters here
}
@@ -5,6 +5,6 @@ import java.lang.annotation.RetentionPolicy;
@Retention(RetentionPolicy.RUNTIME)
public @interface Greeter {
public String greet() default "";
public String greet() default "";
}
@@ -0,0 +1,91 @@
package com.baeldung.javanetworking.uriurl;
import java.io.BufferedReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class URIDemo {
private final Logger logger = LoggerFactory.getLogger(URIDemo.class);
String URISTRING = "https://wordpress.org:443/support/topic/page-jumps-within-wordpress/?replies=3#post-2278484";
// parsed locator
String URISCHEME = "https";
String URISCHEMESPECIFIC;
String URIHOST = "wordpress.org";
String URIAUTHORITY = "wordpress.org:443";
String URIPATH = "/support/topic/page-jumps-within-wordpress/";
int URIPORT = 443;
String URIQUERY = "replies=3";
String URIFRAGMENT = "post-2278484";
String URIUSERINFO;
String URICOMPOUND = URISCHEME + "://" + URIHOST + ":" + URIPORT + URIPATH + "?" + URIQUERY + "#" + URIFRAGMENT;
URI uri;
URL url;
BufferedReader in = null;
String URIContent = "";
private String getParsedPieces(URI uri) {
logger.info("*** List of parsed pieces ***");
URISCHEME = uri.getScheme();
logger.info("URISCHEME: " + URISCHEME);
URISCHEMESPECIFIC = uri.getSchemeSpecificPart();
logger.info("URISCHEMESPECIFIC: " + URISCHEMESPECIFIC);
URIHOST = uri.getHost();
URIAUTHORITY = uri.getAuthority();
logger.info("URIAUTHORITY: " + URIAUTHORITY);
logger.info("URIHOST: " + URIHOST);
URIPATH = uri.getPath();
logger.info("URIPATH: " + URIPATH);
URIPORT = uri.getPort();
logger.info("URIPORT: " + URIPORT);
URIQUERY = uri.getQuery();
logger.info("URIQUERY: " + URIQUERY);
URIFRAGMENT = uri.getFragment();
logger.info("URIFRAGMENT: " + URIFRAGMENT);
try {
url = uri.toURL();
} catch (MalformedURLException e) {
logger.info("MalformedURLException thrown: " + e.getMessage());
e.printStackTrace();
} catch (IllegalArgumentException e) {
logger.info("IllegalArgumentException thrown: " + e.getMessage());
e.printStackTrace();
}
return url.toString();
}
public String testURIAsNew(String URIString) {
// creating URI object
try {
uri = new URI(URIString);
} catch (URISyntaxException e) {
logger.info("URISyntaxException thrown: " + e.getMessage());
e.printStackTrace();
throw new IllegalArgumentException();
}
return getParsedPieces(uri);
}
public String testURIAsCreate(String URIString) {
// creating URI object
uri = URI.create(URIString);
return getParsedPieces(uri);
}
public static void main(String[] args) throws Exception {
URIDemo demo = new URIDemo();
String contentCreate = demo.testURIAsCreate(demo.URICOMPOUND);
demo.logger.info(contentCreate);
String contentNew = demo.testURIAsNew(demo.URICOMPOUND);
demo.logger.info(contentNew);
}
}
@@ -1,9 +1,10 @@
package com.baeldung.javanetworking.url;
package com.baeldung.javanetworking.uriurl;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
@@ -10,7 +10,6 @@ public class JMXTutorialMainlauncher {
private static final Logger LOG = LoggerFactory.getLogger(JMXTutorialMainlauncher.class);
public static void main(String[] args) {
// TODO Auto-generated method stub
@@ -44,7 +44,8 @@ public class MapIteration {
}
public void iterateUsingIteratorAndEntry(Map<String, Integer> map) {
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet().iterator();
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet()
.iterator();
while (iterator.hasNext()) {
Map.Entry<String, Integer> pair = iterator.next();
System.out.println(pair.getKey() + ":" + pair.getValue());
@@ -58,7 +59,9 @@ public class MapIteration {
}
public void iterateUsingStreamAPI(Map<String, Integer> map) {
map.entrySet().stream().forEach(e -> System.out.println(e.getKey() + ":" + e.getValue()));
map.entrySet()
.stream()
.forEach(e -> System.out.println(e.getKey() + ":" + e.getValue()));
}
public void iterateKeys(Map<String, Integer> map) {
@@ -8,7 +8,7 @@ public class BigIntegerImpl {
BigInteger numStarsMilkyWay = new BigInteger("8731409320171337804361260816606476");
BigInteger numStarsAndromeda = new BigInteger("5379309320171337804361260816606476");
BigInteger totalStars = numStarsMilkyWay.add(numStarsAndromeda);
}
@@ -1,4 +1,4 @@
package com.baeldung.java.networking.cookies;
package com.baeldung.networking.cookies;
import java.net.*;
import java.util.List;
@@ -9,7 +9,8 @@ public class PersistentCookieStore implements CookieStore, Runnable {
public PersistentCookieStore() {
store = new CookieManager().getCookieStore();
// deserialize cookies into store
Runtime.getRuntime().addShutdownHook(new Thread(this));
Runtime.getRuntime()
.addShutdownHook(new Thread(this));
}
@Override
@@ -1,4 +1,4 @@
package com.baeldung.java.networking.cookies;
package com.baeldung.networking.cookies;
import java.net.*;
@@ -1,4 +1,4 @@
package com.baeldung.java.networking.udp;
package com.baeldung.networking.udp;
import java.io.IOException;
import java.net.DatagramPacket;
@@ -1,4 +1,4 @@
package com.baeldung.java.networking.udp;
package com.baeldung.networking.udp;
import java.io.IOException;
import java.net.DatagramPacket;
@@ -0,0 +1,85 @@
package com.baeldung.networking.udp.broadcast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.stream.Collectors;
public class BroadcastingClient {
private DatagramSocket socket;
private InetAddress address;
private int expectedServerCount;
private byte[] buf;
public BroadcastingClient(int expectedServerCount) throws Exception {
this.expectedServerCount = expectedServerCount;
this.address = InetAddress.getByName("255.255.255.255");
}
public int discoverServers(String msg) throws IOException {
initializeSocketForBroadcasting();
copyMessageOnBuffer(msg);
// When we want to broadcast not just to local network, call listAllBroadcastAddresses() and execute broadcastPacket for each value.
broadcastPacket(address);
return receivePackets();
}
List<InetAddress> listAllBroadcastAddresses() throws SocketException {
List<InetAddress> broadcastList = new ArrayList<>();
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface networkInterface = interfaces.nextElement();
if (networkInterface.isLoopback() || !networkInterface.isUp()) {
continue;
}
broadcastList.addAll(networkInterface.getInterfaceAddresses()
.stream()
.filter(address -> address.getBroadcast() != null)
.map(address -> address.getBroadcast())
.collect(Collectors.toList()));
}
return broadcastList;
}
private void initializeSocketForBroadcasting() throws SocketException {
socket = new DatagramSocket();
socket.setBroadcast(true);
}
private void copyMessageOnBuffer(String msg) {
buf = msg.getBytes();
}
private void broadcastPacket(InetAddress address) throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length, address, 4445);
socket.send(packet);
}
private int receivePackets() throws IOException {
int serversDiscovered = 0;
while (serversDiscovered != expectedServerCount) {
receivePacket();
serversDiscovered++;
}
return serversDiscovered;
}
private void receivePacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
}
public void close() {
socket.close();
}
}
@@ -0,0 +1,44 @@
package com.baeldung.networking.udp.broadcast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
public class BroadcastingEchoServer extends Thread {
protected DatagramSocket socket = null;
protected boolean running;
protected byte[] buf = new byte[256];
public BroadcastingEchoServer() throws IOException {
socket = new DatagramSocket(null);
socket.setReuseAddress(true);
socket.bind(new InetSocketAddress(4445));
}
public void run() {
running = true;
while (running) {
try {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
String received = new String(packet.getData(), 0, packet.getLength());
if (received.equals("end")) {
running = false;
continue;
}
socket.send(packet);
} catch (IOException e) {
e.printStackTrace();
running = false;
}
}
socket.close();
}
}
@@ -0,0 +1,41 @@
package com.baeldung.networking.udp.multicast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
public class MulticastEchoServer extends Thread {
protected MulticastSocket socket = null;
protected byte[] buf = new byte[256];
protected InetAddress group = null;
public MulticastEchoServer() throws IOException {
socket = new MulticastSocket(4446);
socket.setReuseAddress(true);
group = InetAddress.getByName("230.0.0.0");
socket.joinGroup(group);
}
public void run() {
try {
while (true) {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
String received = new String(packet.getData(), 0, packet.getLength());
if (received.equals("end")) {
break;
}
socket.send(packet);
}
socket.leaveGroup(group);
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@@ -0,0 +1,53 @@
package com.baeldung.networking.udp.multicast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class MulticastingClient {
private DatagramSocket socket;
private InetAddress group;
private int expectedServerCount;
private byte[] buf;
public MulticastingClient(int expectedServerCount) throws Exception {
this.expectedServerCount = expectedServerCount;
this.socket = new DatagramSocket();
this.group = InetAddress.getByName("230.0.0.0");
}
public int discoverServers(String msg) throws IOException {
copyMessageOnBuffer(msg);
multicastPacket();
return receivePackets();
}
private void copyMessageOnBuffer(String msg) {
buf = msg.getBytes();
}
private void multicastPacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
socket.send(packet);
}
private int receivePackets() throws IOException {
int serversDiscovered = 0;
while (serversDiscovered != expectedServerCount) {
receivePacket();
serversDiscovered++;
}
return serversDiscovered;
}
private void receivePacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
}
public void close() {
socket.close();
}
}
@@ -0,0 +1,131 @@
package com.baeldung.numberofdigits;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;;
public class Benchmarking {;
private static final int LOWER_BOUND = 1;
private static final int UPPER_BOUND = 999999999;
public static void main(String[] args) {
LOG.info("Testing all methods...");
long length = test_stringBasedSolution();
LOG.info("String Based Solution : " + length);
length = test_logarithmicApproach();
LOG.info("Logarithmic Approach : " + length);
length = test_repeatedMultiplication();
LOG.info("Repeated Multiplication : " + length);
length = test_shiftOperators();
LOG.info("Shift Operators : " + length);
length = test_dividingWithPowersOf2();
LOG.info("Dividing with Powers of 2 : " + length);
length = test_divideAndConquer();
LOG.info("Divide And Conquer : " + length);
}
private static long test_stringBasedSolution() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.stringBasedSolution(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
private static long test_logarithmicApproach() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.logarithmicApproach(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
private static long test_repeatedMultiplication() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.repeatedMultiplication(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
private static long test_shiftOperators() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.shiftOperators(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
private static long test_dividingWithPowersOf2() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.dividingWithPowersOf2(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
private static long test_divideAndConquer() {
long startTime, stopTime, elapsedTime;
startTime = System.currentTimeMillis();
int total = 0;
for (int i = LOWER_BOUND; i <= UPPER_BOUND; i++) {
total += NumberOfDigits.divideAndConquer(i);
}
stopTime = System.currentTimeMillis();
elapsedTime = stopTime - startTime;
return elapsedTime;
}
}
@@ -0,0 +1,97 @@
package com.baeldung.numberofdigits;
public class NumberOfDigits {
public static int stringBasedSolution(int number) {
int length = String.valueOf(number).length();
return length;
}
public static int logarithmicApproach(int number) {
int length = (int) Math.log10(number) + 1;
return length;
}
public static int repeatedMultiplication(int number) {
int length = 0;
long temp = 1;
while(temp <= number) {
length++;
temp *= 10;
}
return length;
}
public static int shiftOperators(int number) {
int length = 0;
long temp = 1;
while(temp <= number) {
length++;
temp = (temp << 3) + (temp << 1);
}
return length;
}
public static int dividingWithPowersOf2(int number) {
int length = 1;
if (number >= 100000000) {
length += 8;
number /= 100000000;
}
if (number >= 10000) {
length += 4;
number /= 10000;
}
if (number >= 100) {
length += 2;
number /= 100;
}
if (number >= 10) {
length += 1;
}
return length;
}
public static int divideAndConquer(int number) {
if (number < 100000){
// 5 digits or less
if (number < 100){
// 1 or 2
if (number < 10)
return 1;
else
return 2;
}else{
// 3 to 5 digits
if (number < 1000)
return 3;
else{
// 4 or 5 digits
if (number < 10000)
return 4;
else
return 5;
}
}
} else {
// 6 digits or more
if (number < 10000000) {
// 6 or 7 digits
if (number < 1000000)
return 6;
else
return 7;
} else {
// 8 to 10 digits
if (number < 100000000)
return 8;
else {
// 9 or 10 digits
if (number < 1000000000)
return 9;
else
return 10;
}
}
}
}
}
@@ -0,0 +1,27 @@
package com.baeldung.numberofdigits;
import static com.baeldung.designpatterns.util.LogerUtil.LOG;
public class NumberOfDigitsDriver {
public static void main(String[] args) {
LOG.info("Testing all methods...");
long length = NumberOfDigits.stringBasedSolution(602);
LOG.info("String Based Solution : " + length);
length = NumberOfDigits.logarithmicApproach(602);
LOG.info("Logarithmic Approach : " + length);
length = NumberOfDigits.repeatedMultiplication(602);
LOG.info("Repeated Multiplication : " + length);
length = NumberOfDigits.shiftOperators(602);
LOG.info("Shift Operators : " + length);
length = NumberOfDigits.dividingWithPowersOf2(602);
LOG.info("Dividing with Powers of 2 : " + length);
length = NumberOfDigits.divideAndConquer(602);
LOG.info("Divide And Conquer : " + length);
}
}
@@ -14,7 +14,8 @@ public class Screenshot {
}
public void getScreenshot(int timeToWait) throws Exception {
Rectangle rectangle = new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());
Rectangle rectangle = new Rectangle(Toolkit.getDefaultToolkit()
.getScreenSize());
Robot robot = new Robot();
BufferedImage img = robot.createScreenCapture(rectangle);
ImageIO.write(img, "jpg", new File(path));
@@ -8,9 +8,8 @@ import java.net.*;
public class EchoClient {
private static final Logger LOG = LoggerFactory.getLogger(EchoClient.class);
private Socket clientSocket;
private PrintWriter out;
private BufferedReader in;
@@ -1,6 +1,5 @@
package com.baeldung.stream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@@ -12,15 +12,10 @@ class StringHelper {
}
static String removeLastCharOptional(String s) {
return Optional.ofNullable(s)
.filter(str -> str.length() != 0)
.map(str -> str.substring(0, str.length() - 1))
.orElse(s);
return Optional.ofNullable(s).filter(str -> str.length() != 0).map(str -> str.substring(0, str.length() - 1)).orElse(s);
}
static String removeLastCharRegexOptional(String s) {
return Optional.ofNullable(s)
.map(str -> str.replaceAll(".$", ""))
.orElse(s);
return Optional.ofNullable(s).map(str -> str.replaceAll(".$", "")).orElse(s);
}
}
@@ -25,11 +25,7 @@ public class MyTokenizer {
}
public List<String> getTokensWithCollection(String str) {
return Collections
.list(new StringTokenizer(str, ","))
.stream()
.map(token -> (String) token)
.collect(Collectors.toList());
return Collections.list(new StringTokenizer(str, ",")).stream().map(token -> (String) token).collect(Collectors.toList());
}
public List<String> getTokensFromFile(String path, String delim) {
@@ -0,0 +1,22 @@
package com.baeldung.temporaladjuster;
import java.time.DayOfWeek;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjuster;
public class CustomTemporalAdjuster implements TemporalAdjuster {
@Override
public Temporal adjustInto(Temporal temporal) {
switch (DayOfWeek.of(temporal.get(ChronoField.DAY_OF_WEEK))) {
case FRIDAY:
return temporal.plus(3, ChronoUnit.DAYS);
case SATURDAY:
return temporal.plus(2, ChronoUnit.DAYS);
default:
return temporal.plus(1, ChronoUnit.DAYS);
}
}
}
@@ -1,17 +0,0 @@
package com.baeldung.threadlocal;
public class Context {
private final String userName;
public Context(String userName) {
this.userName = userName;
}
@Override
public String toString() {
return "Context{" +
"userNameSecret='" + userName + '\'' +
'}';
}
}
@@ -1,21 +0,0 @@
package com.baeldung.threadlocal;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class SharedMapWithUserContext implements Runnable {
public final static Map<Integer, Context> userContextPerUserId = new ConcurrentHashMap<>();
private final Integer userId;
private UserRepository userRepository = new UserRepository();
public SharedMapWithUserContext(Integer userId) {
this.userId = userId;
}
@Override
public void run() {
String userName = userRepository.getUserNameForUserId(userId);
userContextPerUserId.put(userId, new Context(userName));
}
}
@@ -1,24 +0,0 @@
package com.baeldung.threadlocal;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ThreadLocalWithUserContext implements Runnable {
private static final Logger LOG = LoggerFactory.getLogger(ThreadLocalWithUserContext.class);
private static final ThreadLocal<Context> userContext = new ThreadLocal<>();
private final Integer userId;
private UserRepository userRepository = new UserRepository();
public ThreadLocalWithUserContext(Integer userId) {
this.userId = userId;
}
@Override
public void run() {
String userName = userRepository.getUserNameForUserId(userId);
userContext.set(new Context(userName));
LOG.debug("thread context for given userId: " + userId + " is: " + userContext.get());
}
}
@@ -1,10 +0,0 @@
package com.baeldung.threadlocal;
import java.util.UUID;
public class UserRepository {
public String getUserNameForUserId(Integer userId) {
return UUID.randomUUID().toString();
}
}
@@ -1,20 +0,0 @@
package com.baeldung.threadpool;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveTask;
import java.util.stream.Collectors;
public class CountingTask extends RecursiveTask<Integer> {
private final TreeNode node;
public CountingTask(TreeNode node) {
this.node = node;
}
@Override
protected Integer compute() {
return node.value + node.children.stream().map(childNode -> new CountingTask(childNode).fork()).collect(Collectors.summingInt(ForkJoinTask::join));
}
}
@@ -1,29 +0,0 @@
package com.baeldung.threadpool;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import com.google.common.util.concurrent.MoreExecutors;
/**
* This class demonstrates the usage of Guava's exiting executor services that keep the VM from hanging.
* Without the exiting executor service, the task would hang indefinitely.
* This behaviour cannot be demonstrated in JUnit tests, as JUnit kills the VM after the tests.
*/
public class ExitingExecutorServiceExample {
public static void main(String... args) {
final ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(5);
final ExecutorService executorService = MoreExecutors.getExitingExecutorService(executor, 100, TimeUnit.MILLISECONDS);
executorService.submit((Runnable) () -> {
while (true) {
}
});
}
}
@@ -1,18 +0,0 @@
package com.baeldung.threadpool;
import java.util.Set;
import com.google.common.collect.Sets;
public class TreeNode {
int value;
Set<TreeNode> children;
public TreeNode(int value, TreeNode... children) {
this.value = value;
this.children = Sets.newHashSet(children);
}
}
@@ -1,42 +0,0 @@
package com.baeldung.transferqueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.TransferQueue;
import java.util.concurrent.atomic.AtomicInteger;
public class Consumer implements Runnable {
private static final Logger LOG = LoggerFactory.getLogger(Consumer.class);
private final TransferQueue<String> transferQueue;
private final String name;
private final int numberOfMessagesToConsume;
public final AtomicInteger numberOfConsumedMessages = new AtomicInteger();
public Consumer(TransferQueue<String> transferQueue, String name, int numberOfMessagesToConsume) {
this.transferQueue = transferQueue;
this.name = name;
this.numberOfMessagesToConsume = numberOfMessagesToConsume;
}
@Override
public void run() {
for (int i = 0; i < numberOfMessagesToConsume; i++) {
try {
LOG.debug("Consumer: " + name + " is waiting to take element...");
String element = transferQueue.take();
longProcessing(element);
LOG.debug("Consumer: " + name + " received element: " + element);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
private void longProcessing(String element) throws InterruptedException {
numberOfConsumedMessages.incrementAndGet();
Thread.sleep(500);
}
}
@@ -1,41 +0,0 @@
package com.baeldung.transferqueue;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TransferQueue;
import java.util.concurrent.atomic.AtomicInteger;
public class Producer implements Runnable {
private static final Logger LOG = LoggerFactory.getLogger(Producer.class);
private final TransferQueue<String> transferQueue;
private final String name;
private final Integer numberOfMessagesToProduce;
public final AtomicInteger numberOfProducedMessages = new AtomicInteger();
public Producer(TransferQueue<String> transferQueue, String name, Integer numberOfMessagesToProduce) {
this.transferQueue = transferQueue;
this.name = name;
this.numberOfMessagesToProduce = numberOfMessagesToProduce;
}
@Override
public void run() {
for (int i = 0; i < numberOfMessagesToProduce; i++) {
try {
LOG.debug("Producer: " + name + " is waiting to transfer...");
boolean added = transferQueue.tryTransfer("A" + i, 4000, TimeUnit.MILLISECONDS);
if (added) {
numberOfProducedMessages.incrementAndGet();
LOG.debug("Producer: " + name + " transferred element: A" + i);
} else {
LOG.debug("can not add an element due to the timeout");
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
@@ -6,16 +6,16 @@ import java.security.NoSuchAlgorithmException;
import java.util.UUID;
public class UUIDGenerator {
/**
* These are predefined UUID for name spaces
*/
private static final String NAMESPACE_DNS = "6ba7b810-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_URL = "6ba7b811-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_OID = "6ba7b812-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_X500 = "6ba7b814-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_DNS = "6ba7b810-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_URL = "6ba7b811-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_OID = "6ba7b812-9dad-11d1-80b4-00c04fd430c8";
private static final String NAMESPACE_X500 = "6ba7b814-9dad-11d1-80b4-00c04fd430c8";
private static final char[] hexArray = "0123456789ABCDEF".toCharArray();
private static final char[] hexArray = "0123456789ABCDEF".toCharArray();
public static void main(String[] args) {
try {
@@ -35,7 +35,7 @@ public class UUIDGenerator {
UUID uuid = UUID.randomUUID();
return uuid;
}
/**
* Type 3 UUID Generation
*
@@ -47,7 +47,7 @@ public class UUIDGenerator {
UUID uuid = UUID.nameUUIDFromBytes(bytes);
return uuid;
}
/**
* Type 5 UUID Generation
*
@@ -59,8 +59,7 @@ public class UUIDGenerator {
UUID uuid = type5UUIDFromBytes(bytes);
return uuid;
}
public static UUID type5UUIDFromBytes(byte[] name) {
MessageDigest md;
try {
@@ -69,27 +68,26 @@ public class UUIDGenerator {
throw new InternalError("MD5 not supported", nsae);
}
byte[] bytes = md.digest(name);
bytes[6] &= 0x0f; /* clear version */
bytes[6] |= 0x50; /* set to version 5 */
bytes[8] &= 0x3f; /* clear variant */
bytes[8] |= 0x80; /* set to IETF variant */
bytes[6] &= 0x0f; /* clear version */
bytes[6] |= 0x50; /* set to version 5 */
bytes[8] &= 0x3f; /* clear variant */
bytes[8] |= 0x80; /* set to IETF variant */
return constructType5UUID(bytes);
}
private static UUID constructType5UUID(byte[] data) {
long msb = 0;
long lsb = 0;
assert data.length == 16 : "data must be 16 bytes in length";
for (int i=0; i<8; i++)
for (int i = 0; i < 8; i++)
msb = (msb << 8) | (data[i] & 0xff);
for (int i=8; i<16; i++)
for (int i = 8; i < 16; i++)
lsb = (lsb << 8) | (data[i] & 0xff);
return new UUID(msb, lsb);
}
/**
* Unique Keys Generation Using Message Digest and Type 4 UUID
*
@@ -4,7 +4,7 @@ public class Rectangle extends Shape {
private double width;
private double length;
public Rectangle(double width, double length) {
Rectangle(double width, double length) {
this.width = width;
this.length = length;
}
@@ -1,11 +1,10 @@
package org.baeldung.executable;
import javax.swing.JOptionPane;
import javax.swing.*;
public class ExecutableMavenJar {
public static void main(String[] args) {
JOptionPane.showMessageDialog(null, "It worked!", "Executable Jar with Maven", 1);
}
}
@@ -0,0 +1,9 @@
# Root logger
log4j.rootLogger=INFO, file, stdout
# Write to console
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target=System.out
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
@@ -0,0 +1,82 @@
package com.baeldung;
import org.junit.Test;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
import java.util.concurrent.TimeUnit;
import static org.junit.Assert.assertEquals;
public class DateDiffUnitTest {
@Test
public void givenTwoDatesBeforeJava8_whenDifferentiating_thenWeGetSix() throws ParseException {
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.ENGLISH);
Date firstDate = sdf.parse("06/24/2017");
Date secondDate = sdf.parse("06/30/2017");
long diffInMillies = Math.abs(secondDate.getTime() - firstDate.getTime());
long diff = TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
assertEquals(diff, 6);
}
@Test
public void givenTwoDatesInJava8_whenDifferentiating_thenWeGetSix() {
LocalDate now = LocalDate.now();
LocalDate sixDaysBehind = now.minusDays(6);
Duration duration = Duration.between(now, sixDaysBehind);
long diff = Math.abs(duration.toDays());
assertEquals(diff, 6);
}
@Test
public void givenTwoDateTimesInJava8_whenDifferentiating_thenWeGetSix() {
LocalDateTime now = LocalDateTime.now();
LocalDateTime sixMinutesBehind = now.minusMinutes(6);
Duration duration = Duration.between(now, sixMinutesBehind);
long diff = Math.abs(duration.toMinutes());
assertEquals(diff, 6);
}
@Test
public void givenTwoDatesInJodaTime_whenDifferentiating_thenWeGetSix() {
org.joda.time.LocalDate now = org.joda.time.LocalDate.now();
org.joda.time.LocalDate sixDaysBehind = now.minusDays(6);
org.joda.time.Period period = new org.joda.time.Period(now, sixDaysBehind);
long diff = Math.abs(period.getDays());
assertEquals(diff, 6);
}
@Test
public void givenTwoDateTimesInJodaTime_whenDifferentiating_thenWeGetSix() {
org.joda.time.LocalDateTime now = org.joda.time.LocalDateTime.now();
org.joda.time.LocalDateTime sixMinutesBehind = now.minusMinutes(6);
org.joda.time.Period period = new org.joda.time.Period(now, sixMinutesBehind);
long diff = Math.abs(period.getDays());
}
@Test
public void givenTwoDatesInDate4j_whenDifferentiating_thenWeGetSix() {
hirondelle.date4j.DateTime now = hirondelle.date4j.DateTime.now(TimeZone.getDefault());
hirondelle.date4j.DateTime sixDaysBehind = now.minusDays(6);
long diff = Math.abs(now.numDaysFrom(sixDaysBehind));
assertEquals(diff, 6);
}
}

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