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Android Threads and Services Introducing Services Creating a Service

Milos Ribera
Milos Ribera
9,633 Points

I don't know why it is not working. Anyone can help me?

I'm stuck on stopping the service, but I don't know what I'm doing wrong. If I put stopSelf() method with no arg it returns NullPointerExeption, so I put startId value for Message.arg1 to handle it into the Handler but it's not working. Anyone want to help me, can explain the reasons in order to clarify me the concept. Thank you in advance!

TwitterService.java
public class TwitterService extends Service {
  TwitterClient twitterClient = new TwitterClient();    

  TwitterThread thread;

  @Override
  public void onCreate(){
    thread = new TwitterThread();
    thread.start();
  }

  @Override
  public int onStartCommand(Intent intent, int flags, int startId){
    Message message = Message.obtain();
    message.arg1 = startId;
    thread.twitterHandler.sendMessage(message);
    return Service.START_REDELIVER_INTENT;
  }

  @Override
  public IBinder onBind(Intent intent){
    return null;
  }


  class TwitterThread extends Thread {
    TwitterHandler twitterHandler;
    @Override
    public void run() {
      Looper.prepare();
      twitterHandler = new TwitterHandler();
      Looper.loop();
    }
  }    

  class TwitterHandler extends Handler {
    TwitterService service;
    @Override
    public void handleMessage(Message msg) {
      twitterClient.update();
      service.stopSelf(msg.arg1);
    }
  }
}
MainActivity.java
public class MainActivity extends Activity {
  Button button;   

  @Override
  public void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_main);

    button = (Button) findViewById(R.id.update_button);
    button.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v){
        Intent intent = new Intent(MainActivity.this, TwitterService.class);
        startService(intent);
      }
    });
  }
}