CopyOnWriteArraySet in Java

A thread safe version of the set is the CopyOnWriteArraySet in Java. This set uses an CopyOnWriteArrayList internally for the set operations. The CopyOnWriteArraySet was introduced by the JDK 1.5.

A program that demonstrates this is given as follows −

Example

 Live Demo

import java.util.concurrent.*;
public class Demo extends Thread {
   public static void main(String[] args) {
      CopyOnWriteArraySet cowArraySet = new CopyOnWriteArraySet();
      cowArraySet.add("Amy");
      cowArraySet.add("John");
      cowArraySet.add("Bob");
      cowArraySet.add("Clara");
      cowArraySet.add("Peter");
      System.out.println(cowArraySet);
   }
}

The output of the above program is as follows −

Output

[Amy, John, Bob, Clara, Peter]

Now let us understand the above program.

The CopyOnWriteArraySet is created and then elements are added to it. Then the elements are displayed. A code snippet that demonstrates this is given as follows −

CopyOnWriteArraySet cowArraySet = new CopyOnWriteArraySet();
cowArraySet.add("Amy");
cowArraySet.add("John");
cowArraySet.add("Bob");
cowArraySet.add("Clara");
cowArraySet.add("Peter");
System.out.println(cowArraySet);