Exemplo async task java

asynctask.java

abstract class Task extends Handler implements Runnable{
	public abstract void executeTask();
	public Task(int beginMessage, int endMessage){

	}
	public bool setRunning(){

	}
	public void run(){
		if(this.getRunning())
		{
			sendMessage(beginMessage);
			executeTask();
			sendMessage(endMessage);
		}
	}
}
class RefreshOfertaTask extends Task
{
	public final int BEGIN = 128;
	public final int END = 129;
	public RefreshOfertaTask(){
		super(BEGIN, END);
	}
	@override
	public void executeTask(){
		//TODO: fazer coisas do websevice
	}

}
class Handle{
	public Handle(Tela t){

	}
	void handleMessage(int what){
		switch(what)
		{
			case RefreshOfertaTask.BEGIN:
				t.esconderTela();
				break;
				case RefreshOfertaTask.END:
				t.mostrarTela();
				break;
			default:
				super.handleMessage(what);
				break;
		}
	}
}
class Tela{
	Task tsk = new RefreshOfertaTask();
	Timer t = new Timer(tsk, 120000);
	Handle hwnd;
	public Tela(){
		super();
		hwnd = new Handle(this);
		t.start();
		tsk.setRunning(true);
	}
	void mostrarTela(){

	}
	void esconderTela()	{

	}


	public void onStop(){
		tsk.setRunning(false);
	}


}