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alejandrogervasioKevinGilmore
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KevinGilmore
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BAEL-2287 - An Introduction to Synchronized Java Collections (eugenp#5385)
* Initial Commit * Add pom.xml * Update pom.xml * Update pom.xml * Update SynchronizedSortedMapUnitTest.java
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Lines changed: 293 additions & 90 deletions

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‎core-java-collections/pom.xml‎

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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
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<modelVersion>4.0.0</modelVersion>
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<groupId>com.baeldung</groupId>
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<artifactId>core-java-collections</artifactId>
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<version>0.1.0-SNAPSHOT</version>
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<packaging>jar</packaging>
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<name>core-java-collections</name>
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<parent>
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<groupId>com.baeldung</groupId>
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<artifactId>parent-java</artifactId>
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<version>0.0.1-SNAPSHOT</version>
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<relativePath>../parent-java</relativePath>
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</parent>
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<dependencies>
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<dependency>
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<groupId>net.sourceforge.collections</groupId>
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<artifactId>collections-generic</artifactId>
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<version>${collections-generic.version}</version>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-collections4</artifactId>
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<version>${commons-collections4.version}</version>
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</dependency>
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<dependency>
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<groupId>com.jayway.awaitility</groupId>
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<artifactId>awaitility</artifactId>
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<version>${avaitility.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-lang3</artifactId>
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<version>${commons-lang3.version}</version>
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</dependency>
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<dependency>
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<groupId>org.eclipse.collections</groupId>
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<artifactId>eclipse-collections</artifactId>
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<version>${eclipse.collections.version}</version>
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</dependency>
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<dependency>
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<groupId>org.assertj</groupId>
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<artifactId>assertj-core</artifactId>
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<version>${assertj.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.junit.platform</groupId>
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<artifactId>junit-platform-runner</artifactId>
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<version>${junit.platform.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.openjdk.jmh</groupId>
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<artifactId>jmh-core</artifactId>
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<version>${openjdk.jmh.version}</version>
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</dependency>
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<dependency>
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<groupId>org.openjdk.jmh</groupId>
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<artifactId>jmh-generator-annprocess</artifactId>
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<version>${openjdk.jmh.version}</version>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-exec</artifactId>
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<version>1.3</version>
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</dependency>
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<dependency>
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<groupId>one.util</groupId>
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<artifactId>streamex</artifactId>
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<version>0.6.5</version>
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</dependency>
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</dependencies>
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<properties>
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<openjdk.jmh.version>1.19</openjdk.jmh.version>
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<junit.platform.version>1.2.0</junit.platform.version>
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<commons-lang3.version>3.5</commons-lang3.version>
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<commons-collections4.version>4.1</commons-collections4.version>
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<collections-generic.version>4.01</collections-generic.version>
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<avaitility.version>1.7.0</avaitility.version>
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<assertj.version>3.6.1</assertj.version>
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<eclipse.collections.version>7.1.0</eclipse.collections.version>
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</properties>
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</project>
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<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
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<modelVersion>4.0.0</modelVersion>
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<groupId>com.baeldung</groupId>
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<artifactId>core-java-collections</artifactId>
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<version>0.1.0-SNAPSHOT</version>
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<packaging>jar</packaging>
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<name>core-java-collections</name>
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<parent>
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<groupId>com.baeldung</groupId>
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<artifactId>parent-java</artifactId>
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<version>0.0.1-SNAPSHOT</version>
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<relativePath>../parent-java</relativePath>
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</parent>
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<dependencies>
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<dependency>
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<groupId>net.sourceforge.collections</groupId>
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<artifactId>collections-generic</artifactId>
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<version>${collections-generic.version}</version>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-collections4</artifactId>
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<version>${commons-collections4.version}</version>
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</dependency>
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<dependency>
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<groupId>com.jayway.awaitility</groupId>
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<artifactId>awaitility</artifactId>
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<version>${avaitility.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-lang3</artifactId>
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<version>${commons-lang3.version}</version>
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</dependency>
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<dependency>
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<groupId>org.eclipse.collections</groupId>
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<artifactId>eclipse-collections</artifactId>
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<version>${eclipse.collections.version}</version>
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</dependency>
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<dependency>
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<groupId>org.assertj</groupId>
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<artifactId>assertj-core</artifactId>
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<version>${assertj.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.junit.platform</groupId>
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<artifactId>junit-platform-runner</artifactId>
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<version>${junit.platform.version}</version>
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<scope>test</scope>
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</dependency>
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<dependency>
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<groupId>org.openjdk.jmh</groupId>
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<artifactId>jmh-core</artifactId>
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<version>${openjdk.jmh.version}</version>
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</dependency>
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<dependency>
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<groupId>org.openjdk.jmh</groupId>
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<artifactId>jmh-generator-annprocess</artifactId>
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<version>${openjdk.jmh.version}</version>
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</dependency>
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<dependency>
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<groupId>org.apache.commons</groupId>
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<artifactId>commons-exec</artifactId>
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<version>1.3</version>
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</dependency>
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</dependencies>
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<properties>
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<openjdk.jmh.version>1.19</openjdk.jmh.version>
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<junit.platform.version>1.2.0</junit.platform.version>
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<commons-lang3.version>3.5</commons-lang3.version>
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<commons-collections4.version>4.1</commons-collections4.version>
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<collections-generic.version>4.01</collections-generic.version>
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<avaitility.version>1.7.0</avaitility.version>
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<assertj.version>3.6.1</assertj.version>
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<eclipse.collections.version>7.1.0</eclipse.collections.version>
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</properties>
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</project>

‎core-java-collections/src/main/java/com/baeldung/synchronizedcollections/application/Application.java‎

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package com.baeldung.synchronizedcollections.application;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.List;
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import java.util.logging.Logger;
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public class Application {
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private static final Logger LOGGER = Logger.getLogger(Application.class.getName());
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public static void main(String[] args) throws InterruptedException {
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List<Integer> syncCollection = Collections.synchronizedList(Arrays.asList(1, 2, 3, 4, 5, 6));
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synchronized (syncCollection) {
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syncCollection.forEach((e) -> {LOGGER.info(e.toString());});
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}
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedCollectionUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.Collections;
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import static org.assertj.core.api.Assertions.assertThat;
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import org.junit.Test;
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public class SynchronizedCollectionUnitTest {
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@Test
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public void givenSynchronizedCollection_whenTwoThreadsAddElements_thenCorrectCollectionSize() throws InterruptedException {
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Collection<Integer> syncCollection = Collections.synchronizedCollection(new ArrayList<>());
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Runnable listOperations = () -> {
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syncCollection.addAll(Arrays.asList(1, 2, 3, 4, 5, 6));
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};
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Thread thread1 = new Thread(listOperations);
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Thread thread2 = new Thread(listOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncCollection.size()).isEqualTo(12);
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedListUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.List;
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import org.junit.Test;
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import static org.assertj.core.api.Assertions.*;
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public class SynchronizedListUnitTest {
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@Test
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public void givenSynchronizedList_whenTwoThreadsAddElements_thenCorrectListSize() throws InterruptedException {
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List<Integer> syncList = Collections.synchronizedList(new ArrayList<>());
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Runnable listOperations = () -> {
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syncList.addAll(Arrays.asList(1, 2, 3, 4, 5, 6));
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};
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Thread thread1 = new Thread(listOperations);
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Thread thread2 = new Thread(listOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncList.size()).isEqualTo(12);
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}
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@Test
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public void givenStringList_whenTwoThreadsIterateOnSynchronizedList_thenCorrectResult() throws InterruptedException {
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List<String> syncCollection = Collections.synchronizedList(Arrays.asList("a", "b", "c"));
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List<String> uppercasedCollection = new ArrayList<>();
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Runnable listOperations = () -> {
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synchronized (syncCollection) {
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syncCollection.forEach((e) -> {
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uppercasedCollection.add(e.toUpperCase());
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});
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}
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};
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Thread thread1 = new Thread(listOperations);
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Thread thread2 = new Thread(listOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(uppercasedCollection.get(0)).isEqualTo("A");
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedMapUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.Collections;
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import java.util.HashMap;
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import java.util.Map;
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import org.junit.Test;
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import static org.assertj.core.api.Assertions.*;
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public class SynchronizedMapUnitTest {
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@Test
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public void givenSynchronizedMap_whenTwoThreadsAddElements_thenCorrectMapSize() throws InterruptedException {
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Map<Integer, String> syncMap = Collections.synchronizedMap(new HashMap<>());
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Runnable mapOperations = () -> {
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syncMap.put(1, "one");
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syncMap.put(2, "two");
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syncMap.put(3, "three");
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};
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Thread thread1 = new Thread(mapOperations);
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Thread thread2 = new Thread(mapOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncMap.size()).isEqualTo(3);
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedSetUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.HashSet;
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import java.util.Set;
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import org.junit.Test;
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import static org.assertj.core.api.Assertions.*;
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public class SynchronizedSetUnitTest {
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@Test
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public void givenSynchronizedSet_whenTwoThreadsAddElements_thenCorrectSetSize() throws InterruptedException {
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Set<Integer> syncSet = Collections.synchronizedSet(new HashSet<>());
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Runnable setOperations = () -> {syncSet.addAll(Arrays.asList(1, 2, 3, 4, 5, 6));};
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Thread thread1 = new Thread(setOperations);
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Thread thread2 = new Thread(setOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncSet.size()).isEqualTo(6);
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedSortedMapUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.Collections;
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import java.util.Map;
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import java.util.TreeMap;
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import static org.assertj.core.api.Assertions.assertThat;
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import org.junit.Test;
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public class SynchronizedSortedMapUnitTest {
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@Test
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public void givenSynchronizedSorteMap_whenTwoThreadsAddElements_thenCorrectSortedMapSize() throws InterruptedException {
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Map<Integer, String> syncSortedMap = Collections.synchronizedSortedMap(new TreeMap<>());
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Runnable sortedMapOperations = () -> {
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syncSortedMap.put(1, "One");
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syncSortedMap.put(2, "Two");
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syncSortedMap.put(3, "Three");
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};
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Thread thread1 = new Thread(sortedMapOperations);
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Thread thread2 = new Thread(sortedMapOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncSortedMap.size()).isEqualTo(3);
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}
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}

‎core-java-collections/src/test/java/com/baeldung/synchronizedcollections/test/SynchronizedSortedSetUnitTest.java‎

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package com.baeldung.synchronizedcollections.test;
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import java.util.Arrays;
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import java.util.Collections;
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import java.util.SortedSet;
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import java.util.TreeSet;
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import static org.assertj.core.api.Assertions.assertThat;
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import org.junit.Test;
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public class SynchronizedSortedSetUnitTest {
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@Test
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public void givenSynchronizedSortedSet_whenTwoThreadsAddElements_thenCorrectSortedSetSize() throws InterruptedException {
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SortedSet<Integer> syncSortedSet = Collections.synchronizedSortedSet(new TreeSet<>());
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Runnable sortedSetOperations = () -> {syncSortedSet.addAll(Arrays.asList(1, 2, 3, 4, 5, 6));};
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sortedSetOperations.run();
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sortedSetOperations.run();
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Thread thread1 = new Thread(sortedSetOperations);
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Thread thread2 = new Thread(sortedSetOperations);
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thread1.start();
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thread2.start();
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thread1.join();
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thread2.join();
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assertThat(syncSortedSet.size()).isEqualTo(6);
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}
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}

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