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BAEL-4033 LinkedBlockingQueue vs ConcurrentLinkedQueue (#9281)

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* BAEL-4033 Added unit test cases for LinkedBlockingQueue and ConcurrentLinkedQueue

* BAEL-4033 Updated unit test class names due to PMD rule violations

* Moved files to another module based on the editor review
This commit is contained in:
Somnath Musib 2020-05-20 02:48:58 +10:00 committed by GitHub
parent c395a43472
commit 73762873f6
3 changed files with 155 additions and 1 deletions
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9
core-java-modules/core-java-concurrency-collections-2/pom.xml
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@ -23,7 +23,12 @@
<artifactId>jmh-generator-annprocess</artifactId>
<version>${jmh.version}</version>
</dependency>
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<version>${assertj.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
@ -42,6 +47,8 @@
<properties>
<jmh.version>1.21</jmh.version>
<guava.version>28.2-jre</guava.version>
<!-- testing -->
<assertj.version>3.6.1</assertj.version>
</properties>
</project>

66
core-java-modules/core-java-concurrency-collections-2/src/test/java/com/baeldung/concurrent/queue/TestConcurrentLinkedQueue.java Normal file
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@ -0,0 +1,66 @@
package com.baeldung.concurrent.queue;
import static org.assertj.core.api.Assertions.assertThat;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertThat;
import java.util.Arrays;
import java.util.Collection;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import org.junit.FixMethodOrder;
import org.junit.Test;
@FixMethodOrder
public class TestConcurrentLinkedQueue {
@Test
public void givenThereIsExistingCollection_WhenAddedIntoQueue_ThenShouldContainElements() {
Collection<Integer> elements = Arrays.asList(1, 2, 3, 4, 5);
ConcurrentLinkedQueue<Integer> concurrentLinkedQueue = new ConcurrentLinkedQueue<>(elements);
assertThat(concurrentLinkedQueue).containsExactly(1, 2, 3, 4, 5);
}
@Test
public void givenQueueIsEmpty_WhenAccessingTheQueue_ThenQueueReturnsNull() throws InterruptedException {
ExecutorService executorService = Executors.newFixedThreadPool(1);
ConcurrentLinkedQueue<Integer> concurrentLinkedQueue = new ConcurrentLinkedQueue<>();
executorService.submit(() -> assertNull("Retrieve object is null", concurrentLinkedQueue.poll()));
TimeUnit.SECONDS.sleep(1);
executorService.awaitTermination(1, TimeUnit.SECONDS);
executorService.shutdown();
}
@Test
public void givenProducerOffersElementInQueue_WhenConsumerPollsQueue_ThenItRetrievesElement() throws Exception {
int element = 1;
ExecutorService executorService = Executors.newFixedThreadPool(2);
ConcurrentLinkedQueue<Integer> concurrentLinkedQueue = new ConcurrentLinkedQueue<>();
Runnable offerTask = () -> concurrentLinkedQueue.offer(element);
Callable<Integer> pollTask = () -> {
while (concurrentLinkedQueue.peek() != null) {
return concurrentLinkedQueue.poll()
.intValue();
}
return null;
};
executorService.submit(offerTask);
TimeUnit.SECONDS.sleep(1);
Future<Integer> returnedElement = executorService.submit(pollTask);
assertThat(returnedElement.get()
.intValue(), is(equalTo(element)));
executorService.awaitTermination(1, TimeUnit.SECONDS);
executorService.shutdown();
}
}

81
core-java-modules/core-java-concurrency-collections-2/src/test/java/com/baeldung/concurrent/queue/TestLinkedBlockingQueue.java Normal file
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@ -0,0 +1,81 @@
package com.baeldung.concurrent.queue;
import static org.assertj.core.api.Assertions.assertThat;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import java.util.Arrays;
import java.util.Collection;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;
import org.junit.FixMethodOrder;
import org.junit.Test;
@FixMethodOrder
public class TestLinkedBlockingQueue {
@Test
public void givenThereIsExistingCollection_WhenAddedIntoQueue_ThenShouldContainElements() {
Collection<Integer> elements = Arrays.asList(1, 2, 3, 4, 5);
LinkedBlockingQueue<Integer> linkedBlockingQueue = new LinkedBlockingQueue<>(elements);
assertThat(linkedBlockingQueue).containsExactly(1, 2, 3, 4, 5);
}
@Test
public void givenQueueIsEmpty_WhenAccessingTheQueue_ThenThreadBlocks() throws InterruptedException {
ExecutorService executorService = Executors.newFixedThreadPool(1);
LinkedBlockingQueue<Integer> linkedBlockingQueue = new LinkedBlockingQueue<>();
executorService.submit(() -> {
try {
linkedBlockingQueue.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
});
TimeUnit.SECONDS.sleep(1);
executorService.awaitTermination(1, TimeUnit.SECONDS);
executorService.shutdown();
}
@Test
public void givenProducerPutsElementInQueue_WhenConsumerAccessQueue_ThenItRetrieve() {
int element = 10;
ExecutorService executorService = Executors.newFixedThreadPool(2);
LinkedBlockingQueue<Integer> linkedBlockingQueue = new LinkedBlockingQueue<>();
Runnable putTask = () -> {
try {
linkedBlockingQueue.put(element);
} catch (InterruptedException e) {
e.printStackTrace();
}
};
Callable<Integer> takeTask = () -> {
try {
return linkedBlockingQueue.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
};
executorService.submit(putTask);
Future<Integer> returnElement = executorService.submit(takeTask);
try {
TimeUnit.SECONDS.sleep(1);
assertThat(returnElement.get()
.intValue(), is(equalTo(element)));
executorService.awaitTermination(1, TimeUnit.SECONDS);
} catch (Exception e) {
e.printStackTrace();
}
executorService.shutdown();
}
}