Question on Thread interrupt method.

[Siva Masilamani]

Hi

I am preparing for SCJP exam and came across this question in Devaka exam.Could somebody please explain why the user thread is not interrupted even though main thread set the interrupt when the user thread is sleeping?

I see the output as Ex-B followed by exception.Why not Ex-A is not printed?Why the interrupt method not woking here?

public class A extends Thread{

     public static void doDelay(long t){

          try{
              System.out.println(Thread.currentThread().getName()+" is sleeping");
               Thread.sleep(t);
               System.out.println(Thread.currentThread().getName()+" is now "+Thread.currentThread().getState());
               
          }catch(InterruptedException e){
               System.out.print("Ex-A ");
          }

     }

     public void run(){
          doDelay(1000);
          halt();
     }

     public void halt(){

          try{
               this.wait();
          }catch(Exception e){
               System.out.print("Ex-B ");
          }

     }

     public static void main(String args[]){
          A a=new A();
          Thread t=new Thread(a);
          t.start();
          doDelay(100);
          System.out.println("Main thread Setting interrupt for  other thread");
          a.interrupt();
          doDelay(2000);
          t.notifyAll();
     }

} 

[Siva Masilamani]

Hi

I got the answer myself.We are setting the interrupt only on 'a' not on 't'.