Android Speech Recognition Continuous Service

Question

I'm trying to create a service to run continuous speech recognition in Android 4.2. Using the answer from this link ( Android Speech Recognition as a service on Android 4.1 & 4.2 ), I created a service that is run from an Activity. My problem is that I get null exceptions when accessing mTarget.mAudioManager or mTarget.mSpeechRecognizerIntent in the handleMessage method. The target (and mTarget object created from it) is not null, but all the objects inside it are.

What am I doing wrong here?

Relevant Activity Code (static methods called from activity, activityContext is the activity this method is called from):

public static void init(Context context) {    voiceCommandService = new VoiceCommandService();    activityContext = context; }  public static void startContinuousListening() {     Intent service = new Intent(activityContext, VoiceCommandService.class);     activityContext.startService(service);      Message msg = new Message();     msg.what = VoiceCommandService.MSG_RECOGNIZER_START_LISTENING;       try     {       voiceCommandService.mServerMessenger.send(msg);     }      catch (RemoteException e)    {     e.printStackTrace();    }  } 

Service Code:

public class VoiceCommandService extends Service { protected AudioManager mAudioManager;  protected SpeechRecognizer mSpeechRecognizer; protected Intent mSpeechRecognizerIntent; protected final Messenger mServerMessenger = new Messenger(new IncomingHandler(this));  protected boolean mIsListening; protected volatile boolean mIsCountDownOn;  static final int MSG_RECOGNIZER_START_LISTENING = 1; static final int MSG_RECOGNIZER_CANCEL = 2;  @Override public void onCreate() {     super.onCreate();     mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);      mSpeechRecognizer = SpeechRecognizer.createSpeechRecognizer(this);     mSpeechRecognizer.setRecognitionListener(new SpeechRecognitionListener());     mSpeechRecognizerIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);     mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL,                                      RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);     mSpeechRecognizerIntent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE,                                      this.getPackageName()); }  protected static class IncomingHandler extends Handler {     private WeakReference<VoiceCommandService> mtarget;      IncomingHandler(VoiceCommandService target)     {         mtarget = new WeakReference<VoiceCommandService>(target);     }       @Override     public void handleMessage(Message msg)     {         final VoiceCommandService target = mtarget.get();          switch (msg.what)         {             case MSG_RECOGNIZER_START_LISTENING:                  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)                 {                     // turn off beep sound                       target.mAudioManager.setStreamMute(AudioManager.STREAM_SYSTEM, true);                 }                  if (!target.mIsListening)                  {                      target.mSpeechRecognizer.startListening(target.mSpeechRecognizerIntent);                      target.mIsListening = true;                     //Log.d(TAG, "message start listening"); //$NON-NLS-1$                  }                  break;               case MSG_RECOGNIZER_CANCEL:                   target.mSpeechRecognizer.cancel();                   target.mIsListening = false;                   //Log.d(TAG, "message canceled recognizer"); //$NON-NLS-1$                   break;          }    }  }   // Count down timer for Jelly Bean work around protected CountDownTimer mNoSpeechCountDown = new CountDownTimer(5000, 5000) {      @Override     public void onTick(long millisUntilFinished)     {         // TODO Auto-generated method stub      }      @Override     public void onFinish()     {         mIsCountDownOn = false;         Message message = Message.obtain(null, MSG_RECOGNIZER_CANCEL);         try         {             mServerMessenger.send(message);             message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);             mServerMessenger.send(message);         }         catch (RemoteException e)         {          }     } };  @Override public void onDestroy() {     super.onDestroy();      if (mIsCountDownOn)     {         mNoSpeechCountDown.cancel();     }     if (mSpeechRecognizer != null)     {         mSpeechRecognizer.destroy();     } }  protected class SpeechRecognitionListener implements RecognitionListener {      private static final String TAG = "SpeechRecognitionListener";      @Override     public void onBeginningOfSpeech()     {         // speech input will be processed, so there is no need for count down anymore         if (mIsCountDownOn)         {             mIsCountDownOn = false;             mNoSpeechCountDown.cancel();         }                        //Log.d(TAG, "onBeginingOfSpeech"); //$NON-NLS-1$     }      @Override     public void onBufferReceived(byte[] buffer)     {      }      @Override     public void onEndOfSpeech()     {         //Log.d(TAG, "onEndOfSpeech"); //$NON-NLS-1$      }      @Override     public void onError(int error)     {         if (mIsCountDownOn)         {             mIsCountDownOn = false;             mNoSpeechCountDown.cancel();         }          mIsListening = false;          Message message = Message.obtain(null, MSG_RECOGNIZER_START_LISTENING);          try          {                 mServerMessenger.send(message);          }          catch (RemoteException e)          {           }         //Log.d(TAG, "error = " + error); //$NON-NLS-1$     }      @Override     public void onEvent(int eventType, Bundle params)     {      }      @Override     public void onPartialResults(Bundle partialResults)     {      }      @Override     public void onReadyForSpeech(Bundle params)     {         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)         {             mIsCountDownOn = true;             mNoSpeechCountDown.start();             mAudioManager.setStreamMute(AudioManager.STREAM_SYSTEM, false);         }         Log.d(TAG, "onReadyForSpeech"); //$NON-NLS-1$     }      @Override     public void onResults(Bundle results)     {         //Log.d(TAG, "onResults"); //$NON-NLS-1$      }      @Override     public void onRmsChanged(float rmsdB)     {      }  }  @Override public IBinder onBind(Intent arg0) {     // TODO Auto-generated method stub     return null; } } 

Answer 1

Class members in MainActivity

private int mBindFlag; private Messenger mServiceMessenger; 

Start service in onCreate()

@Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      Intent service = new Intent(activityContext, VoiceCommandService.class);     activityContext.startService(service);     mBindFlag = Build.VERSION.SDK_INT < Build.VERSION_CODES.ICE_CREAM_SANDWICH ? 0 : Context.BIND_ABOVE_CLIENT;  } 

Bind service in onStart()

@Override protected void onStart() {     super.onStart();      bindService(new Intent(this, VoiceCommandService.class), mServiceConnection, mBindFlag); }  @Override protected void onStop() {     super.onStop();      if (mServiceMessenger != null)     {         unbindService(mServiceConnection);         mServiceMessenger = null;     } } 

mServiceConnection member

private final ServiceConnection mServiceConnection = new ServiceConnection() {     @Override     public void onServiceConnected(ComponentName name, IBinder service)     {         if (DEBUG) {Log.d(TAG, "onServiceConnected");} //$NON-NLS-1$          mServiceMessenger = new Messenger(service);         Message msg = new Message();         msg.what = VoiceCommandService.MSG_RECOGNIZER_START_LISTENING;           try         {             mServiceMessenger.send(msg);         }          catch (RemoteException e)         {             e.printStackTrace();         }     }      @Override     public void onServiceDisconnected(ComponentName name)     {         if (DEBUG) {Log.d(TAG, "onServiceDisconnected");} //$NON-NLS-1$         mServiceMessenger = null;     }  }; // mServiceConnection 

In the service

@Override public IBinder onBind(Intent intent) {     Log.d(TAG, "onBind");  //$NON-NLS-1$      return mServerMessenger.getBinder(); } 

Answer 2

Working example is given below,

MyService.class

public class MyService extends Service implements SpeechDelegate, Speech.stopDueToDelay {    public static SpeechDelegate delegate;    @Override   public int onStartCommand(Intent intent, int flags, int startId) {     //TODO do something useful     try {       if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {         ((AudioManager) Objects.requireNonNull(           getSystemService(Context.AUDIO_SERVICE))).setStreamMute(AudioManager.STREAM_SYSTEM, true);       }     } catch (Exception e) {       e.printStackTrace();     }      Speech.init(this);     delegate = this;     Speech.getInstance().setListener(this);      if (Speech.getInstance().isListening()) {       Speech.getInstance().stopListening();     } else {       System.setProperty("rx.unsafe-disable", "True");       RxPermissions.getInstance(this).request(permission.RECORD_AUDIO).subscribe(granted -> {         if (granted) { // Always true pre-M           try {             Speech.getInstance().stopTextToSpeech();             Speech.getInstance().startListening(null, this);           } catch (SpeechRecognitionNotAvailable exc) {             //showSpeechNotSupportedDialog();            } catch (GoogleVoiceTypingDisabledException exc) {             //showEnableGoogleVoiceTyping();           }         } else {           Toast.makeText(this, R.string.permission_required, Toast.LENGTH_LONG).show();         }       });     }     return Service.START_STICKY;   }    @Override   public IBinder onBind(Intent intent) {     //TODO for communication return IBinder implementation     return null;   }    @Override   public void onStartOfSpeech() {   }    @Override   public void onSpeechRmsChanged(float value) {    }    @Override   public void onSpeechPartialResults(List<String> results) {     for (String partial : results) {       Log.d("Result", partial+"");     }   }    @Override   public void onSpeechResult(String result) {     Log.d("Result", result+"");     if (!TextUtils.isEmpty(result)) {       Toast.makeText(this, result, Toast.LENGTH_SHORT).show();     }   }    @Override   public void onSpecifiedCommandPronounced(String event) {     try {       if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {         ((AudioManager) Objects.requireNonNull(           getSystemService(Context.AUDIO_SERVICE))).setStreamMute(AudioManager.STREAM_SYSTEM, true);       }     } catch (Exception e) {       e.printStackTrace();     }     if (Speech.getInstance().isListening()) {       Speech.getInstance().stopListening();     } else {       RxPermissions.getInstance(this).request(permission.RECORD_AUDIO).subscribe(granted -> {         if (granted) { // Always true pre-M           try {             Speech.getInstance().stopTextToSpeech();             Speech.getInstance().startListening(null, this);           } catch (SpeechRecognitionNotAvailable exc) {             //showSpeechNotSupportedDialog();            } catch (GoogleVoiceTypingDisabledException exc) {             //showEnableGoogleVoiceTyping();           }         } else {           Toast.makeText(this, R.string.permission_required, Toast.LENGTH_LONG).show();         }       });     }   }     @Override   public void onTaskRemoved(Intent rootIntent) {     //Restarting the service if it is removed.     PendingIntent service =       PendingIntent.getService(getApplicationContext(), new Random().nextInt(),         new Intent(getApplicationContext(), MyService.class), PendingIntent.FLAG_ONE_SHOT);      AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);     assert alarmManager != null;     alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, 1000, service);     super.onTaskRemoved(rootIntent);   } } 

For more details,

https://github.com/sachinvarma/Speech-Recognizer

Hope this will help someone in future.