Camera.takepicture Null Pointer Exception

I always get a NullPointerException when I try to take a picture using this code. It always fails at camera.takePicture. I tried to google the issue and didnt find anything. Any he

Solution 1:

I think camera is null in your onClick() function because there is no guaranteed path in onCreate() to create the camera.

Modify onClick() as follows:

publicvoidonClick(View view) {
    if(camera == null) {
        // Warn user that camera is not available via "Toast" or similar.
    } else {
        camera.takePicture(null, null,
            newPhotoHandler(getApplicationContext()));
    }
}

Solution 2:

I got the same compatibility issue between 2.3 and 4.0. Here I assumed you called startPreview() before you call takePicture().

Please see my code below, it works for me both 2.3 and 4.0 devices.

PictureCallback mJpegCallback;
SurfaceView surfaceViewDummy;
Camera mCamera;
mCamera = Camera.open();
try {

    // Important here!!! If use below line under 2.3 works,// but not work on 4.0! Will always got // java.lang.RuntimeException: takePicture failed// Under 4.0 must create a real SurfaceView object on the screen!//surfaceViewDummy = new SurfaceView(this);
    surfaceViewDummy = (SurfaceView) findViewById(R.id.surfaceView1);

    mCamera.setPreviewDisplay(surfaceViewDummy.getHolder());
    mCamera.startPreview();
} catch (Exception e) {

    Log.d("", "Start preview error " + e.toString());
}

mJpegCallback = new PictureCallback() {

    publicvoidonPictureTaken(byte[] data, Camera camera) {
        Log.d("", "Got picture data");
        // Save the picture data by yourself// ...
    }
};

mCamera.takePicture(null, null, mJpegCallback);

Solution 3:

Do your application permission to use the Camera?

<uses-permissionandroid:name="android.permission.CAMERA"/>

Solution 4:

Try to add this to your manifest file

<uses-featureandroid:name="android.hardware.camera"/>

This will tell the device that the app uses the camera For more information http://developer.android.com/guide/topics/media/camera.html

Solution 5:

I am using the same code as yours in my application and my app too used to throw null pointer exception on the line :

camera.takePicture(null, null,new PhotoHandler(getApplicationContext()));

I think this is caused due to the camera getting a null value.To avoid this exception I put a check on top of this line of code.So that the onClick function looks like :

publicvoidonClick(View view) {
  if (camera != null) {
    Log.d("camera state","camera is NOT null");  
  }else{
    Log.d("camera state","camera is null");
    camera = android.hardware.Camera.open(cameraId);
  }
  camera.takePicture(null, null,newPhotoHandler(getApplicationContext()));
}

Hope it helps !