iSharkFly-Docs
/
java-tutorials
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

time-based UUIDs

This commit is contained in:
alexandru.borza 2023-03-17 19:58:29 +02:00
parent 9089d84d2b
commit e14feb5351
3 changed files with 99 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
core-java-modules/core-java-uuid/pom.xml
View File

@ -25,6 +25,21 @@
<artifactId>log4j-over-slf4j</artifactId>
<version>${org.slf4j.version}</version>
</dependency>
<dependency>
<groupId>com.github.f4b6a3</groupId>
<artifactId>uuid-creator</artifactId>
<version>5.2.0</version>
</dependency>
<dependency>
<groupId>com.fasterxml.uuid</groupId>
<artifactId>java-uuid-generator</artifactId>
<version>4.1.0</version>
</dependency>
<dependency>
<groupId>com.github.f4b6a3</groupId>
<artifactId>tsid-creator</artifactId>
<version>5.2.3</version>
</dependency>
</dependencies>
<build>
@ -143,4 +158,4 @@
<maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
</properties>
</project>
</project>

42
core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/JavaUUIDCreator.java Normal file
View File

@ -0,0 +1,42 @@
package com.baeldung.timebaseduuid;
import com.fasterxml.uuid.Generators;
import com.github.f4b6a3.uuid.UuidCreator;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
public class JavaUUIDCreator {
public static void main(String[] args) throws InterruptedException {
int threadCount = 128;
int iterationCount = 100_000;
ConcurrentMap<UUID, Long> uuidMap = new ConcurrentHashMap<>();
AtomicLong collisionCount = new AtomicLong();
long startNanos = System.nanoTime();
CountDownLatch endLatch = new CountDownLatch(threadCount);
for (long i = 0; i < threadCount; i++) {
final long threadId = i;
new Thread(() -> {
for (long j = 0; j < iterationCount; j++) {
UUID uuid = Generators.timeBasedGenerator().generate();
Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
if(existingUUID != null) {
collisionCount.incrementAndGet();
}
}
endLatch.countDown();
}).start();
}
endLatch.await();
System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
+ TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
}
}

41
core-java-modules/core-java-uuid/src/main/java/com/baeldung/timebaseduuid/UUIDCreator.java Normal file
View File

@ -0,0 +1,41 @@
package com.baeldung.timebaseduuid;
import com.github.f4b6a3.uuid.UuidCreator;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
public class UUIDCreator {
public static void main(String[] args) throws InterruptedException {
int threadCount = 128;
int iterationCount = 100_000;
ConcurrentMap<UUID, Long> uuidMap = new ConcurrentHashMap<>();
AtomicLong collisionCount = new AtomicLong();
long startNanos = System.nanoTime();
CountDownLatch endLatch = new CountDownLatch(threadCount);
for (long i = 0; i < threadCount; i++) {
final long threadId = i;
new Thread(() -> {
for (long j = 0; j < iterationCount; j++) {
UUID uuid = UuidCreator.getTimeBased();
Long existingUUID = uuidMap.put(uuid, (threadId * iterationCount) + j);
if(existingUUID != null) {
collisionCount.incrementAndGet();
}
}
endLatch.countDown();
}).start();
}
endLatch.await();
System.out.println(threadCount * iterationCount + " UUIDs generated, " + collisionCount + " collisions in "
+ TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNanos) + "ms");
}
}