Generating Time Based UUIDs (#13668)
* time-based UUIDs * review * review
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@ -24,6 +24,21 @@
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<artifactId>log4j-over-slf4j</artifactId>
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<version>${org.slf4j.version}</version>
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</dependency>
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<dependency>
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<groupId>com.github.f4b6a3</groupId>
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<artifactId>uuid-creator</artifactId>
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<version>5.2.0</version>
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</dependency>
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<dependency>
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<groupId>com.fasterxml.uuid</groupId>
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<artifactId>java-uuid-generator</artifactId>
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<version>4.1.0</version>
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</dependency>
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<dependency>
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<groupId>com.github.f4b6a3</groupId>
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<artifactId>tsid-creator</artifactId>
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<version>5.2.3</version>
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</dependency>
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</dependencies>
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<build>
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@ -142,4 +157,4 @@
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<maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
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</properties>
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</project>
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</project>
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@ -0,0 +1,42 @@
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package com.baeldung.timebaseduuid;
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import com.fasterxml.uuid.Generators;
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import java.util.Map;
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import java.util.UUID;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.concurrent.CountDownLatch;
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import java.util.concurrent.TimeUnit;
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import java.util.concurrent.atomic.AtomicLong;
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public class JavaUUIDCreatorBenchmark {
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public static void main(String[] args) throws InterruptedException {
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int threadCount = 128;
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int iterationCount = 100_000;
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Map<UUID, Long> uuidMap = new ConcurrentHashMap<>();
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AtomicLong collisionCount = new AtomicLong();
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long startNanos = System.nanoTime();
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CountDownLatch endLatch = new CountDownLatch(threadCount);
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for (long i = 0; i < threadCount; i++) {
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long threadId = i;
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new Thread(() -> {
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for (long j = 0; j < iterationCount; j++) {
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UUID uuid = Generators.timeBasedGenerator().generate();
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Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
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if(existingUUID != null) {
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collisionCount.incrementAndGet();
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}
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}
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endLatch.countDown();
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}).start();
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}
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endLatch.await();
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System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
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+ TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
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}
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}
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@ -0,0 +1,13 @@
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package com.baeldung.timebaseduuid;
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import com.fasterxml.uuid.Generators;
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public class JavaUUIDCreatorExample {
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public static void main(String[] args) {
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System.out.println("UUID Version 1: " + Generators.timeBasedGenerator().generate());
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System.out.println("UUID Version 6: " + Generators.timeBasedReorderedGenerator().generate());
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System.out.println("UUID Version 7: " + Generators.timeBasedEpochGenerator().generate());
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}
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}
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package com.baeldung.timebaseduuid;
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import com.github.f4b6a3.uuid.UuidCreator;
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import java.util.Map;
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import java.util.UUID;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.concurrent.ConcurrentMap;
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import java.util.concurrent.CountDownLatch;
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import java.util.concurrent.TimeUnit;
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import java.util.concurrent.atomic.AtomicLong;
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public class UUIDCreatorBenchmark {
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public static void main(String[] args) throws InterruptedException {
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int threadCount = 128;
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int iterationCount = 100_000;
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Map<UUID, Long> uuidMap = new ConcurrentHashMap<>();
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AtomicLong collisionCount = new AtomicLong();
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long startNanos = System.nanoTime();
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CountDownLatch endLatch = new CountDownLatch(threadCount);
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for (long i = 0; i < threadCount; i++) {
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long threadId = i;
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new Thread(() -> {
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for (long j = 0; j < iterationCount; j++) {
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UUID uuid = UuidCreator.getTimeBased();
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Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
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if(existingUUID != null) {
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collisionCount.incrementAndGet();
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}
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}
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endLatch.countDown();
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}).start();
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}
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endLatch.await();
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System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
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+ TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
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}
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}
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@ -0,0 +1,13 @@
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package com.baeldung.timebaseduuid;
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import com.github.f4b6a3.uuid.UuidCreator;
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public class UUIDCreatorExample {
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public static void main(String[] args) {
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System.out.println("UUID Version 1: " + UuidCreator.getTimeBased());
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System.out.println("UUID Version 6: " + UuidCreator.getTimeOrdered());
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System.out.println("UUID Version 7: " + UuidCreator.getTimeOrderedEpoch());
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}
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}
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