DemoJoin.java

package chapter11;


//Using join() to wait for threads to finish

class NewThread4 implements Runnable {

    String name;
    Thread t;

    NewThread4(String threadName) {
        name = threadName;
        t = new Thread(this, name);
        System.out.println("New Thread " + t);
    }


    public void run() {
        try {
            for (int i = 5; i > 0; i--) {
                System.out.println(name+" : " + i);
                Thread.sleep(1000);
            }
        } catch (InterruptedException e) {
            System.out.println(name + " interrupted");
        }
        System.out.println(name+" exiting");

    }
}


public class DemoJoin {

    public static void main(String[] args) {

        NewThread4 nt1 =new NewThread4("One");
        NewThread4 nt2 =new NewThread4("Two");
        NewThread4 nt3 =new NewThread4("Three");

        nt1.t.start();
        nt2.t.start();
        nt3.t.start();

        System.out.println("Thread one is alive "+nt1.t.isAlive());
        System.out.println("Thread two is alive "+nt2.t.isAlive());
        System.out.println("Thread three is alive "+nt3.t.isAlive());

        try {
            System.out.println("Waiting for threads to finish");
            nt1.t.join();
            nt2.t.join();
            nt3.t.join();

        }catch (InterruptedException e){
            System.out.println("Main thread interrupted.");
        }
        System.out.println("Thread one is alive "+nt1.t.isAlive());
        System.out.println("Thread two is alive "+nt2.t.isAlive());
        System.out.println("Thread three is alive "+nt3.t.isAlive());

        System.out.println("Main thread exiting.");


    }
}