In this example we shall show you how to make use of ThreadLocalRandom class, ThreadLocalRandom is a random number generator like its parent Random class. Like the global Random generator class, a ThreadLocalRandom is initialized with an internally generated seed that may not otherwise be modified.
1. ThreadLocalRandom Advantages
ThreadLocalRandomprovide more good performance and less overhead in in concurrent programs than the sharedRandomobject. So, the usage ofThreadLocalRandomis particularly appropriate when multiple tasks (for example, each aForkJoinTask) use random numbers in parallel in thread pools.ThreadLocalRandomdoes not support the explicit setting of seed for more true randomness. Also, If we try to overridesetSeed(long)method, anUnsupportedOperationExceptionwill be thrown because theThreadLocalRandomprohibits explicit setting of its seed by overriding Random’ssetSeed(long)method and automatically throwing anUnsupportedOperationExceptionif called.
2. Example
Usages of this class should typically be of the form: ThreadLocalRandom.current().nextX(...) (where X is int, long, etc). When all usages are of this form, it is never possible to accidentally share a ThreadLocalRandom across multiple threads.
ThreadLocalRandomTest:
package com.jcg;
import java.util.concurrent.ThreadLocalRandom;
/**
* @author ashraf
*
*/
public class ThreadLocalRandomTest {
public static void main(String[] args) {
System.out.println("Random int:");
// Returns a pseudorandom, uniformly distributed integer value between 0
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextInt(10000));
// Returns a pseudorandom, uniformly distributed int value between 5000
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextInt(5000, 10000));
System.out.println("Random long:");
// Returns a pseudorandom, uniformly distributed long value between 0
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextLong(10000));
// Returns a pseudorandom, uniformly distributed long value between 5000
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextLong(5000, 10000));
System.out.println("Random double:");
// Returns a pseudorandom, uniformly distributed long value between 0
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextDouble(10000));
// Returns a pseudorandom, uniformly distributed long value between 5000
// (inclusive) and 10000 (exclusive)
System.out.println(ThreadLocalRandom.current().nextDouble(5000, 10000));
}
}
Output:
Random int: 8821 6475 Random long: 9739 5238 Random double: 2813.5399468694077 8616.95174974552
Download the Source Code of this example:
This was an example of Java ThreadLocalRandom class.
Download
You can download the full source code of this example here: ThreadLocalRandomExampleCode.zip
You can download the full source code of this example here: ThreadLocalRandomExampleCode.zip
