Ошибка приложения при нажатии кнопки «Назад» из действия камеры

Question

Я пытаюсь сделать приложение детектора движения, которое захватывает изображения при обнаружении движения. Его рабочий тон & с сохранением изображений. Проблема в том, что приложение вылетает, когда я нажимаю кнопку «назад» из действия камеры, чтобы вернуться к домашней активности. Как это исправить? Вот мой код:

public class MotionDetectionActivity extends SensorsActivity { 

private static final String TAG = "MotionDetectionActivity"; 
private static final String ENABLE_MOTION_DETECTION="switch_md"; 

private static SurfaceView preview = null; 
private static SurfaceHolder previewHolder = null; 
private static Camera camera = null; 
private static boolean inPreview = false; 
private static long mReferenceTime = 0; 
private static IMotionDetection detector = null; 
public static MediaPlayer song; 
public static Vibrator mVibrator; 

private static volatile AtomicBoolean processing = new AtomicBoolean(false); 
public int MY_PERMISSIONS_REQUEST_CAMERA; 
/** 
* {@inheritDoc} 
*/ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); 
    setContentView(R.layout.main); 

    SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this); 
    boolean enablemotionpref = sharedPref.getBoolean(ENABLE_MOTION_DETECTION, true); 


    song = MediaPlayer.create(this, R.raw.sound); 
    mVibrator = (Vibrator)this.getSystemService(VIBRATOR_SERVICE); 

    preview = (SurfaceView) findViewById(R.id.preview); 
    previewHolder = preview.getHolder(); 
    previewHolder.addCallback(surfaceCallback); 
    previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS); 

    if (enablemotionpref) { 

     if (Preferences.USE_RGB) { 
      detector = new RgbMotionDetection(); 
     } else if (Preferences.USE_LUMA) { 
      detector = new LumaMotionDetection(); 
     } else { 
      // Using State based (aggregate map) 
      detector = new AggregateLumaMotionDetection(); 
     } 
    } 
} 

/** 
* {@inheritDoc} 
*/ 
@Override 
public void onConfigurationChanged(Configuration newConfig) { 
    super.onConfigurationChanged(newConfig); 
} 

/** 
* {@inheritDoc} 
*/ 
@Override 
public void onPause() { 
    super.onPause(); 
    if(song!=null && song.isPlaying()) 
    { 
     song.stop();} 

    camera.setPreviewCallback(null); 
    if (inPreview) camera.stopPreview(); 
    inPreview = false; 
    camera.release(); 
    camera = null; 
} 

/** 
* {@inheritDoc} 
*/ 
@Override 
public void onResume() { 
    super.onResume(); 

    camera = Camera.open(); 
} 

private PreviewCallback previewCallback = new PreviewCallback() { 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public void onPreviewFrame(byte[] data, Camera cam) { 
     if (data == null) return; 
     Camera.Size size = cam.getParameters().getPreviewSize(); 
     if (size == null) return; 

     if (!GlobalData.isPhoneInMotion()) { 
      DetectionThread thread = new DetectionThread(data, size.width, size.height); 
      thread.start(); 
     } 
    } 
}; 

private SurfaceHolder.Callback surfaceCallback = new SurfaceHolder.Callback() { 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public void surfaceCreated(SurfaceHolder holder) { 
     try { 
      camera.setPreviewDisplay(previewHolder); 
      camera.setPreviewCallback(previewCallback); 
     } catch (Throwable t) { 
      Log.e("Callback", "Exception in setPreviewDisplay()", t); 
     } 
    } 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
     Camera.Parameters parameters = camera.getParameters(); 
     Camera.Size size = getBestPreviewSize(width, height, parameters); 
     if (size != null) { 
      parameters.setPreviewSize(size.width, size.height); 
      Log.d(TAG, "Using width=" + size.width + " height=" + size.height); 
     } 
     camera.setParameters(parameters); 
     camera.startPreview(); 
     inPreview = true; 
    } 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public void surfaceDestroyed(SurfaceHolder holder) { 
     // Ignore 
    } 
}; 

private static Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) { 
    Camera.Size result = null; 

    for (Camera.Size size : parameters.getSupportedPreviewSizes()) { 
     if (size.width <= width && size.height <= height) { 
      if (result == null) { 
       result = size; 
      } else { 
       int resultArea = result.width * result.height; 
       int newArea = size.width * size.height; 

       if (newArea > resultArea) result = size; 
      } 
     } 
    } 

    return result; 
} 

private static final class DetectionThread extends Thread { 

    private byte[] data; 
    private int width; 
    private int height; 

    public DetectionThread(byte[] data, int width, int height) { 
     this.data = data; 
     this.width = width; 
     this.height = height; 
    } 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    public void run() { 
     if (!processing.compareAndSet(false, true)) return; 

     // Log.d(TAG, "BEGIN PROCESSING..."); 
     try { 
      // Previous frame 
      int[] pre = null; 
      if (Preferences.SAVE_PREVIOUS) pre = detector.getPrevious(); 

      // Current frame (with changes) 
      // long bConversion = System.currentTimeMillis(); 
      int[] img = null; 
      if (Preferences.USE_RGB) { 
       img = ImageProcessing.decodeYUV420SPtoRGB(data, width, height); 

       if (img != null && detector.detect(img, width, height)) 
       { 
        if(song!=null && !song.isPlaying()) 
        { 
         song.start(); 
         mVibrator.vibrate(50); 
        } 
       } 
       else 
       { 
        if(song!=null && song.isPlaying()) 
        { 
         song.pause(); 

        } 
       } 
      } 

      // Current frame (without changes) 
      int[] org = null; 
      if (Preferences.SAVE_ORIGINAL && img != null) org = img.clone(); 

      if (img != null && detector.detect(img, width, height)) { 
       // The delay is necessary to avoid taking a picture while in 
       // the 
       // middle of taking another. This problem can causes some 
       // phones 
       // to reboot. 
       long now = System.currentTimeMillis(); 
       if (now > (mReferenceTime + Preferences.PICTURE_DELAY)) { 
        mReferenceTime = now; 

        Bitmap previous = null; 
        if (Preferences.SAVE_PREVIOUS && pre != null) { 
         if (Preferences.USE_RGB) previous = ImageProcessing.rgbToBitmap(pre, width, height); 
         else previous = ImageProcessing.lumaToGreyscale(pre, width, height); 
        } 

        Bitmap original = null; 
        if (Preferences.SAVE_ORIGINAL && org != null) { 
         if (Preferences.USE_RGB) original = ImageProcessing.rgbToBitmap(org, width, height); 
         else original = ImageProcessing.lumaToGreyscale(org, width, height); 
        } 

        Bitmap bitmap = null; 
        if (Preferences.SAVE_CHANGES) { 
         if (Preferences.USE_RGB) bitmap = ImageProcessing.rgbToBitmap(img, width, height); 
         else bitmap = ImageProcessing.lumaToGreyscale(img, width, height); 
        } 

        Log.i(TAG, "Saving.. previous=" + previous + " original=" + original + " bitmap=" + bitmap); 
        Looper.prepare(); 
        new SavePhotoTask().execute(previous, original, bitmap); 
       } else { 
        Log.i(TAG, "Not taking picture because not enough time has passed since the creation of the Surface"); 
       } 
      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } finally { 
      processing.set(false); 
     } 
     // Log.d(TAG, "END PROCESSING..."); 

     processing.set(false); 
    } 
}; 

private static final class SavePhotoTask extends AsyncTask<Bitmap, Integer, Integer> { 

    /** 
    * {@inheritDoc} 
    */ 
    @Override 
    protected Integer doInBackground(Bitmap... data) { 
     for (int i = 0; i < data.length; i++) { 
      Bitmap bitmap = data[i]; 
      String name = "MotDet_"+String.valueOf(System.currentTimeMillis()); 
      if (bitmap != null) createDirectoryAndSaveFile(name, bitmap); 
     } 
     return 1; 
    } 

private void createDirectoryAndSaveFile(String name, Bitmap bitmap) { 

File folder = new File(Environment.getExternalStorageDirectory() + 
     File.separator + "MD");//here you have created different name 
boolean success = true; 
if (!folder.exists()) { 
    success = folder.mkdirs(); 
} 
if (success) { 
    // Do something on success 

} else { 
    // Do something else on failure 
} 

File photo = new File(folder.getAbsolutePath(), name+ ".jpg"); //use path of above created folder 
if (photo.exists()) { 
    photo.delete(); 
} 
try { 
    FileOutputStream out = new FileOutputStream(photo.getPath()); 
    bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out); 
    out.flush(); 
    out.close(); 
} catch (Exception e) { 
    e.printStackTrace(); 
} 
} 
} 
} 

HomeActivity

public class HomeActivity extends AppCompatActivity { 


@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); 
    setContentView(R.layout.home_layout); 



    Button bt1 = (Button) findViewById(R.id.button); 
    Button bt2= (Button)findViewById(R.id.button1); 
    bt1.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent i = new Intent(view.getContext(), MotionDetectionActivity.class); 
      startActivity(i); 
     } 
    }); 

    bt2.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View vew) { 
      Intent b=new Intent(vew.getContext(),SettingsActivity.class); 
      startActivity(b); 

     } 
    }); 
} 
} 

StackTrace

Answer 1

ручка, как ли это увидеть, если он по-прежнему падает

@Override 
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
     if(camera != null) { 
     Camera.Parameters parameters = camera.getParameters(); 
     Camera.Size size = getBestPreviewSize(width, height, parameters); 
     if (size != null) { 
      parameters.setPreviewSize(size.width, size.height); 
      Log.d(TAG, "Using width=" + size.width + " height=" + size.height); 
     } 
     camera.setParameters(parameters); 
     camera.startPreview(); 
     inPreview = true; 
     } 
    }