ThreadGroups in Java Programming

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java.lang ThreadGroup class is used to make a group of threads.ThreadGroup is used to represent more than one thread as a single thread. We can start or suspend all related threads within a group with a single method call.

We can make thread group using one of following :
        public Thread(ThreadGroup group, Runnable target)
        public Thread(ThreadGroup group, String name)
        public Thread(ThreadGroup group, Runnable target, String name)
eg.
        ThreadGroup tg = new ThreadGroup("Group of Threads");
        Thread myThread = new Thread(tg, new R4R());

    
We can use getThreadGroup() method to get thread groups:

        theGroup = td.getThreadGroup();

The ThreadGroup class has two constructors.

ThreadGroup(String name)
ThreadGroup(ThreadGroup parent, String name)

 public class ThreadGroupTest{
 public static void main(String[] args){
  ThreadGroup tg = new ThreadGroup("test");
  Thread t1 = new Thread(tg, new T(), "t1"); 
  Thread t2 = new Thread(tg, new T(), "t2"); 
  t1.start(); 
  t2.start();
}
}

class R4R implements Runnable{
 public void run(){
  for(int i = 1; i < 50; i++){
   System.out.println(i);   
  }
 } 
}

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