Wie halten Sie WebSockets als Hintergrunddienst?

Question

Ich habe einen Dienst, um meine Websocket-Ereignisse zu behandeln, aber es hört auf zu hören, wenn die Benutzeroberfläche geschlossen ist - aber ich kann immer noch Nachrichten ausgeben (z. B. Standortdaten). Wie kann ich WebSockets im Hintergrund laufen lassen, damit es beim Booten auf Ereignisse wartet oder wenn der Haupt-UI-Thread geschlossen wird?

public class HomeActivity extends AppCompatActivity 
     implements NavigationView.OnNavigationItemSelectedListener { 
    public static final String TAG = HomeActivity.class.getSimpleName(); 
    public static final String PREFS_NAME = "MyPrefsFile"; 
    String userName = "init"; 
    String token = "init"; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_home); 
     WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); 
     WifiInfo wInfo = wifiManager.getConnectionInfo(); 
     String macAddress = wInfo.getMacAddress(); 
     TextView textView = (TextView) findViewById(R.id.txtMac); 
     textView.setText(macAddress); 

     startService(new Intent(getBaseContext(), wsService.class)); 

     SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); 
     userName = settings.getString("username","does not exist"); 
     token = settings.getString("token","does not exist"); 
     textView = (TextView) findViewById(R.id.txtEmail); 
     textView.setText(userName); 

     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 
     getSupportActionBar().setTitle("Beacon"); 

     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
       this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close); 
     drawer.setDrawerListener(toggle); 
     toggle.syncState(); 

     NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); 
     navigationView.setNavigationItemSelectedListener(this); 
    } 


    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      super.onBackPressed(); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     // Inflate the menu; this adds items to the action bar if it is present. 
     getMenuInflater().inflate(R.menu.home, menu); 
     return true; 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml. 
     int id = item.getItemId(); 

     //noinspection SimplifiableIfStatement 
     if (id == R.id.action_settings) { 
      return true; 
     } 

     return super.onOptionsItemSelected(item); 
    } 

    @SuppressWarnings("StatementWithEmptyBody") 
    @Override 
    public boolean onNavigationItemSelected(MenuItem item) { 
     // Handle navigation view item clicks here. 
     int id = item.getItemId(); 

     if (id == R.id.nav_camera) { 
      // Handle the camera action 
     } else if (id == R.id.nav_gallery) { 

     } else if (id == R.id.nav_slideshow) { 

     } else if (id == R.id.nav_manage) { 

     } else if (id == R.id.nav_share) { 

     } else if (id == R.id.nav_send) { 

     } else if (id == R.id.nav_logout) { 
      Log.i(TAG, "<<<<---- LOGOUT ---->>> "); 
      Intent i = new Intent(getApplicationContext(), HomeActivity.class); 
      startActivity(i); 
     } 


     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 
} 

Dies ist der Dienst von der Aktivität oben gestartet wird:

public class wsService extends Service implements OnPreparedListener { 
    public static final String PREFS_NAME = "MyPrefsFile"; 
    double longitude = 0; 
    double latitude = 0; 
    long time = 0; 
    float speed = 0; 
    float accuracy = 0; 
    float bearing = 0; 
    boolean sound_stopped = true; 
    String userName = "init"; 
    String token = "init"; 
    public static final String TAG = wsService.class.getSimpleName(); 
    private LocationRequest mLocationRequest; 
    MediaPlayer mp; 

    /** indicates how to behave if the service is killed */ 
    int mStartMode; 

    /** interface for clients that bind */ 
    IBinder mBinder; 

    /** indicates whether onRebind should be used */ 
    boolean mAllowRebind; 
    private Socket mSocket; 
    { 
     try { 
      mSocket = IO.socket("http://192.168.0.2:5000"); 
     } catch (URISyntaxException e) {} 

    } 

    /** Called when the service is being created. */ 
    @Override 
    public void onCreate() { 
     Log.d(TAG, "-- Starting wsService --"); 
     new LongOperation().execute("test"); 
     mp = MediaPlayer.create(this, R.raw.led); 
     String locationProvider = LocationManager.NETWORK_PROVIDER; 
     mLocationRequest = LocationRequest.create() // Create the LocationRequest object 
       .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY) 
       .setInterval(10 * 1000)  // 10 seconds, in milliseconds 
       .setFastestInterval(1 * 1000); // 1 second, in milliseconds 
     // Acquire a reference to the system Location Manager 
     LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); 
     locationManager.requestLocationUpdates(locationProvider, 0, 0, locationListener); 
    } 

    private class LongOperation extends AsyncTask<String, Void, String> { 

     @Override 
     protected String doInBackground(String... params) { 
      Log.d(TAG, "-- Starting BACKGROUND wsService --"); 
      mSocket.connect(); 
      mSocket.on("to_mobile", onCommand); 
      return "Executed"; 
     } 

     @Override 
     protected void onPostExecute(String result) { 

     } 

     @Override 
     protected void onPreExecute() {} 

     @Override 
     protected void onProgressUpdate(Void... values) {} 
    } 

    //Listening new message event to receive message 
    private Emitter.Listener onCommand = new Emitter.Listener() { 
     @Override 
     public void call(final Object... args) { 
      JSONObject data = (JSONObject)args[0]; 
      String command = null; 
      try { 
       command = data.getString("command"); 
      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 

      Log.i(TAG, "<<<<---- RECEIVING COMMAND ----->>> " + command); 
      if (command.equals("ping_audio_start")) { 
       start_sound(); 
      } 
      if (command.equals("ping_audio_stop")) { 
       stop_sound(); 
      } 
      if (command.equals("ping_gps")) { 
       Log.i(TAG, "<<<<---- RESPONDING GPS REQUEST ----->>> "); 
       mSocket.emit("from_mobile", gps_string); 
      } 

     } 
    }; 

    String gps_string = "HELLO FROM DROID"; 
    private void handleNewLocation(Location location) { 
     WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE); 
     WifiInfo wInfo = wifiManager.getConnectionInfo(); 
     String macAddress = wInfo.getMacAddress(); 
     longitude = location.getLongitude(); 
     latitude = location.getLatitude(); 
     time = location.getTime(); 
     speed = location.getSpeed(); 
     accuracy = location.getAccuracy(); 
     bearing = location.getBearing(); 
     SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0); 
     userName = settings.getString("username","does not exist"); 
     token = settings.getString("token","does not exist"); 
     gps_string = "{ \"mac\":\"" + macAddress 
       + "\", \"userName\":\"" + userName 
       + "\", \"token\":\"" + token 
       + "\", \"time\":\"" + time 
       + "\", \"longitude\":\"" + longitude 
       + "\", \"latitude\":\"" + latitude 
       + "\", \"speed\":\"" + speed 
       + "\", \"accuracy\":\"" + accuracy 
       + "\", \"bearing\":\"" + bearing 
       + "\"}"; 
     mSocket.emit("from_mobile", gps_string); 
     Log.i(TAG, "<<<<---- SENDING GPS DATA ---->>> "); 
    } 

    // Define a listener that responds to location updates 
    LocationListener locationListener = new LocationListener() { 
     public void onLocationChanged(Location location) { 
      handleNewLocation(location); 
     } 
     public void onStatusChanged(String provider, int status, Bundle extras) {} 

     public void onProviderEnabled(String provider) {} 

     public void onProviderDisabled(String provider) {} 
    }; 

    public void start_sound() { 
     Log.i(TAG, "<<<<---- START PING ----->>>"); 
     mp.release(); 
     mp = MediaPlayer.create(this, R.raw.led); 
     mp.setLooping(true); 
     mp.start(); 
     mp.setVolume(1, 1); 
     sound_stopped = false; 

    } 
    public void stop_sound() { 
     Log.i(TAG, "<<<<---- STOP PING ----->>> "); 
     mp.stop(); 
     sound_stopped = true; 
    } 

    public void onPrepared(MediaPlayer player) { 
     player.start(); 
    } 
     /** The service is starting, due to a call to startService() */ 
    @Override 
    public int onStartCommand(Intent intent, int flags, int startId) { 
     return mStartMode; 
    } 

    /** A client is binding to the service with bindService() */ 
    @Override 
    public IBinder onBind(Intent intent) { 
     return mBinder; 
    } 

    /** Called when all clients have unbound with unbindService() */ 
    @Override 
    public boolean onUnbind(Intent intent) { 
     return mAllowRebind; 
    } 

    /** Called when a client is binding to the service with bindService()*/ 
    @Override 
    public void onRebind(Intent intent) { 

    } 

    /** Called when The service is no longer used and is being destroyed */ 
    @Override 
    public void onDestroy() { 

    } 
} 

Answer 1

IntentService läuft als nur solange der es die Absicht behandeln muss. Wenn es keine Absichten mehr zum Verarbeiten gibt, schließt der Dienst automatisch.

Versuchen Sie stattdessen einen normalen Dienst.