Question

I am starting a service from activity.The problem here is the service gets started started but the activity is not getting displayed.

@Override
protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.main);
           startService(new Intent(this, ServerActivity1.class));

        }

In the service I am opening a socket via a simple function like this by using a timer.The service gets started as I am able to see in logs but the view(R.layout.main) never gets displayed and after some time the force close pop is displayed.

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

@Override
public void onCreate() {
    Toast.makeText(this, "sasa", Toast.LENGTH_SHORT).show();
    timer.scheduleAtFixedRate( new TimerTask() {
        public void run() {
            read();

        } 
    }, 0,50000);
    Log.i("NoServer","Started1");   
    read();

}

@Override
public void onDestroy() {

}

@Override
public void onStart(Intent intent, int startid) {
     Log.i("Home","Listening on IP: " + SERVERIP+"\n");
}


public  void  read()
{
    SERVERIP = getLocalIpAddress();
   Log.i("Home","Listening on IP: " + SERVERIP+"\n");
               if (SERVERIP != null) {
                Log.i("Home","Listening on IP: " + SERVERIP+"\n");
                }
                try {
                    serverSocket = new         ServerSocket(SERVERPORT);
                } catch (IOException e1) {
                    e1.printStackTrace();
                }
                   while (true) {
                      Socket client;
                      Log.i("Home","Listening on IP: " + SERVERIP+"\n");
                    try {
                            client = serverSocket.accept();
                            Log.i("Home","Listening on IP: " + SERVERIP+"\n");
                           BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
                            while ((line = in.readLine()) != null) {                                                            
                            serverSocket.close();
                            read();
                        }

                       } catch (Exception e) {

                           e.printStackTrace();
                       }
                   }
          } 

Answer 1

Its because your UI thread (main) is being shared by service unless you define your service in a separate process in manifest. If you start your service in activity’s onResume method, till then your service would be visible but still may cause ANR depending on the time (max 5 secs) it takes to complete requests in service.

Its better to put all the socket stuff (or any expensive calls) of your service in a separate thread. In that case, your app will not hang or crash due to ANR.

You should use ThreadHandler and Handler to execute Messages and/or Runnables in a separate thread inside Service.