Java Examples - Display all running Thread?

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Problem Description

How to display all running Thread?

Solution

Following example demonstrates how to display names of all the running threads using getName() method.

public class Main extends Thread {
   public static void main(String[] args) {
      Main t1 = new Main();
      t1.setName("thread1");
      t1.start();
      ThreadGroup currentGroup = Thread.currentThread().getThreadGroup();
      int noThreads = currentGroup.activeCount();
      Thread[] lstThreads = new Thread[noThreads];
      currentGroup.enumerate(lstThreads);
      
      for (int i = 0; i < noThreads; i++) System.out.println("Thread No:" + i + " = " + lstThreads[i].getName());
   }
}

Result

The above code sample will produce the following result.

Thread No:0 = main
Thread No:1 = thread1