title: Mediaplayer NullPointerException?
body: <p>I use mediaplayer at my ringtones application (mp3 sounds). It is working correctly but I see error report on google play developer console (for some users),I couldn't find the bug on my device,thank you</p>
  
  <pre><code>public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
  
      soundname= new String[]  {"Sound1","Sound2","Sound3","Sound4","Sound5","Sound6"}; 
      soundfile= new int[] {R.raw.sound1,R.raw.sound2,R.raw.sound3,R.raw.sound4,R.raw.sound5,R.raw.sound6};
  
      this.setContentView(R.layout.single_list_item_view);
  
      TextView txtProduct = (TextView) findViewById(R.id.product_label);
      Intent intent = getIntent();
      int position = intent.getExtras().getInt("position");
  
      txtProduct.setText(soundname[position]);
      stopPlaying();  
      mediaPlayer = MediaPlayer.create(this, soundfile[position]); 
  
      Button btnplay= (Button) findViewById(R.id.btnoynat);
      btnplay.setOnClickListener(new View.OnClickListener(){
  
          public void onClick(View arg0) { 
                  mediaPlayer.start();         
          }
          });
  }
  
  private void stopPlaying() {
      if (mediaPlayer != null) {
          mediaPlayer.stop();
          mediaPlayer.release();
          mediaPlayer = null;
    }}
  </code></pre>
  
  <p>Error log; (mediaPlayer.start();-->SingleListItem.java:60)</p>
  
  <pre><code>java.lang.NullPointerException
  at com.zilsesleri.SingleListItem$1.onClick(SingleListItem.java:60)  
  at android.view.View.performClick(View.java:2538)
  at android.view.View$PerformClick.run(View.java:9152)
  at android.os.Handler.handleCallback(Handler.java:587)
  at android.os.Handler.dispatchMessage(Handler.java:92)
  at android.os.Looper.loop(Looper.java:130)
  at android.app.ActivityThread.main(ActivityThread.java:3693)
  at java.lang.reflect.Method.invokeNative(Native Method)
  at java.lang.reflect.Method.invoke(Method.java:507)
  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
  at dalvik.system.NativeStart.main(Native Method)
  </code></pre>