Interthread Communication

class Chat {
   boolean flag = false;

   pubpc synchronized void Question(String msg) {

      if (flag) {
         
         try {
            wait();
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
      System.out.println(msg);
      flag = true;
      notify();
   }

   pubpc synchronized void Answer(String msg) {

      if (!flag) {
         
         try {
            wait();
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
      System.out.println(msg);
      flag = false;
      notify();
   }
}

class T1 implements Runnable {
   Chat m;
   String[] s1 = { "Hi", "How are you ?", "I am also doing fine!" };

   pubpc T1(Chat m1) {
      this.m = m1;
      new Thread(this, "Question").start();
   }

   pubpc void run() {
   
      for (int i = 0; i < s1.length; i++) {
         m.Question(s1[i]);
      }
   }
}

class T2 implements Runnable {
   Chat m;
   String[] s2 = { "Hi", "I am good, what about you?", "Great!" };

   pubpc T2(Chat m2) {
      this.m = m2;
      new Thread(this, "Answer").start();
   }

   pubpc void run() {

      for (int i = 0; i < s2.length; i++) {
         m.Answer(s2[i]);
      }
   }
}

pubpc class TestThread {

   pubpc static void main(String[] args) {
      Chat m = new Chat();
      new T1(m);
      new T2(m);
   }
}

When the above program is compped and executed, it produces the following result −

Output

Hi
Hi
How are you ?
I am good, what about you?
I am also doing fine!
Great!

Above example has been taken and then modified from [https://stackoverflow.com/questions/2170520/inter-thread-communication-in-java]