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Asked: 2020-05-18 11:51:00 +0800 CST 2020-05-18 11:51:00 +0800 CST

Kill a thread in Android onBackPressed()

  • 772

I'm trying to kill this thread as soon as I hit the back button. But in "HiloConsumo" it does not pick up the thread reference well

        new Thread("HiloConsumo") {
        public void run() {

            while (true) {
                System.out.println("----------------------------------");
                    // stock.print();

                } catch (Exception ex) {
                }
            }
        }
    }.start();
}

public void onBackPressed() {
    if (HiloConsumo != null)//valida si existe.
    {
        HiloConsumo.interrupt();  //Interrumpe su ejecución.
    }
}
java

1 Answers

  1. Best Answer

    This would be the correct way to interrupt the execution of a Thread :

    You create the Thread:

    Thread myThread = new Thread("ThreadEduardo");

    in this way you validate if it exists and proceed to stop its execution.

      if(myThread != null){  //valida si existe.
      myThread.interrupt();  //Interrumpe su ejecución.          
  }

    The stop() method is not used as it is deprecated.

    stop() This method was deprecated in API level 1. This method is inherently unsafe. Stopping a thread with Thread.stop causes it to unblock all monitors it has locked (as a natural consequence of the unchecked ThreadDeath exception propagating up the stack).

    This is an example for you to see the operation of the Thread and its interruption.

    You declare a type variable Thread:

    private Thread HiloConsumo;
private static final String TAG = "MainActivity";

    Create a class that extends Thread:

     private class MyThread extends Thread {
        @Override
        public void run(){
            while(true) {
                Log.d(TAG, "En ejecucion: " + HiloConsumo.getName() + " | " + System.currentTimeMillis());
                try {
                    sleep(1000); //pausa un segundo.
                } catch (InterruptedException e) {
                    Log.e(TAG, "Error " + e.getMessage());
                }
            }
        }
    }

    You would create your Thread like this:

      HiloConsumo = new MyThread(); //crea instancia.
  HiloConsumo.setName("Hilo Eduardo"); //Asigna nombre.
  HiloConsumo.start(); //inicia Thread.

    when calling onBackPressed() you can see that the execution is interrupted:

      public void onBackPressed() {
        if (HiloConsumo != null)//valida si existe instancia de Thread.
        {
            Log.d(TAG, "interrumpe Thread!" + HiloConsumo.getName());
            HiloConsumo.interrupt();  //Interrumpe su ejecución.
        }
    }
    • 2