Calling an AsyncTask from another AsyncTask

Question

At a certain point of my AsyncTask, after some validations have been done, I need to spawn off another thread to do some other work. So I\'d like two background threads at t

Answer 1

This can be done using message passing concurrency and a single handler. Proof of concept code follows:

private Handler myHandler= new Handler(){
    @Override
    public void  handleMessage(Message msg){         
        switch(msg.what){
            case 0:
                Toast.makeText(Main.this,"Message0", Toast.LENGTH_SHORT).show();
                Thread thread= new Thread( new Runnable() {
                    public void run() {
                        try {
                            Thread.sleep(3000);
                        }
                        catch(Exception e){}
                        myHandler.sendEmptyMessage(2);
                    }       
                });
                thread.setDaemon(true); // <== I am a service provider. KILL ME if the non-daemon thread ConfuseText quits
                thread.start();   

            break;
            case 1:
                Toast.makeText(Main.this,"Message1", Toast.LENGTH_SHORT).show();
                break;
            case 2:
                Toast.makeText(Main.this,"Message2", Toast.LENGTH_SHORT).show();
                break;
            default:
                super.handleMessage(msg);
                break;
        }
    }
};

I launched the first thread on a button click as in:

 ON CLICK HANDLER
            threadButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                Thread thread= new Thread( new Runnable() {
                    public void run() {
                        try {
                        Thread.sleep(1000);
                        }
                        catch(Exception e){ 
                        }
                        myHandler.sendEmptyMessage(0);
                        try {
                        Thread.sleep(3000);
                        }
                        catch(Exception e){ 
                        }
                        myHandler.sendEmptyMessage(1);
                    }
                });
                thread.setDaemon(true); // <== I am a service provider. KILL ME if the non-daemon thread ConfuseText quits
                thread.start();
            }
});

The calls to thread sleep is to mimic a time intensive task.