Nullpointer Exception "void android.media.MediaPlayer.setDataSource(android.content.Context, android.net.Uri)"

Question

I'm trying to take a music file from the music folder of the user in a Fragment, but when I do that and after receiving it in onActivityResult (and logging it), I get a Nullpointer Exception when I want to play it with media player. The code to pick the file:

    Button pickFile = (Button) v.findViewById(R.id.btnpick);
    pickFile.setOnClickListener(new OnClickListener() {

   @Override
        public void onClick(View v) {
        Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI);
        startActivityForResult(intent, 1);
        }
    });

OnActivityResult (Don't forgetting that I'm in a fragment)

  public void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data); 
  getActivity();
  if ((resultCode == getActivity().RESULT_OK) && (data != null)) {
  Log.d("result", "okreceived");
  Uri soundUri = Uri.parse(data.getData().toString());
  Log.i("result", "Intent data " + data.getData().toString());
  mplayergo(soundUri);
       }
  if (resultCode == getActivity().RESULT_CANCELED)
  {
  //null
  }
        }

       public void mplayergo(Uri soundUri){
           try {
               mplayer.setDataSource(getActivity(), soundUri);
               mplayer.start();
           } catch (IOException e) {
               e.printStackTrace();

           } catch (Exception e) {
               e.printStackTrace();
           }

        }

Here's the log:

D/result: okreceived I/result: Intent data content://media/external/audio/media/34839 W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaPlayer.setDataSource(android.content.Context, android.net.Uri)' on a null object reference at com.package.example.GameFragment.mplayergo(GameFragment.java:764) at com.package.example.GameFragment.onActivityResult(GameFragment.java:748) W/System.err: at android.support.v4.app.FragmentActivity.onActivityResult(FragmentActivity.java:156) W/System.err: at android.app.Activity.dispatchActivityResult(Activity.java:6290) W/System.err: at android.app.ActivityThread.deliverResults(ActivityThread.java:3606) W/System.err: at android.app.ActivityThread.handleSendResult(ActivityThread.java:3653) W/System.err: at android.app.ActivityThread.access$1400(ActivityThread.java:154) W/System.err: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1371) W/System.err: at android.os.Handler.dispatchMessage(Handler.java:102) W/System.err:
at android.os.Looper.loop(Looper.java:135) W/System.err: at android.app.ActivityThread.main(ActivityThread.java:5300) W/System.err: at java.lang.reflect.Method.invoke(Native Method) W/System.err: at java.lang.reflect.Method.invoke(Method.java:372) W/System.err: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:904) W/System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:699)

Solved by re-initializing MediaPlayer and setting the URI as a source.

 public void mplayergo(Uri soundUri){
       try {
           mplayer.stop();
           mplayer.reset();
           mplayer.release();
           mplayer = MediaPlayer.create(getActivity(), soundUri);
          // mplayer.start();
       } catch (Exception e) {
           e.printStackTrace();
       }
    }

Solution

mplayer is not initialized. So when you try to invoke the method setDataSource it gets null pointer exception. Try to initialize mplayer before invoking that method.

Comments

[Spidersaw]

Yes, I had to re-initialize it and now it works, thank you :)