Importance of join() method in Java?

JavaObject Oriented ProgrammingProgramming

A join() is a final method of Thread class and it can be used to join the start of a thread's execution to the end of another thread's execution so that a thread will not start running until another thread has ended. If the join() method is called on a thread instance, the currently running thread will block until the thread instance has finished executing.

Syntax

public final void join() throws InterruptedException

Example

public class JoinTest extends Thread {
   public void run() {
      for(int i=1; i <= 3; i++) {
         try {
            Thread.sleep(1000);
         } catch(Exception e) {
            System.out.println(e);
         }
         System.out.println("TutorialsPoint "+ i);
      }
   }
   public static void main(String args[]) {
      JoinTest t1 = new JoinTest();
      JoinTest t2 = new JoinTest();
      JoinTest t3 = new JoinTest();
      t1.start();
      try {
         t1.join(); // calling join() method
      } catch(Exception e) {
         System.out.println(e);
      }
      t2.start();
      t3.start();
   }
}

Output

TutorialsPoint 1
TutorialsPoint 2
TutorialsPoint 3
TutorialsPoint 1
TutorialsPoint 1
TutorialsPoint 2
TutorialsPoint 2
TutorialsPoint 3
TutorialsPoint 3
raja
Published on 21-Aug-2019 12:52:13
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