java.lang.IllegalStateException what does it mean?

Question

I'm developing a video application. After 1st video playback done, in the "OnCopletion" I'm trying to start a new one. But it just stops (not crashes) and do nothing. In the log:

10-19 09:44:49.056: ERROR/MediaPlayer(4654): setDataSource called in state 128 10-19 09:44:49.056: WARN/System.err(4654): java.lang.IllegalStateException 10-19 09:44:49.056: WARN/System.err(4654):     at android.media.MediaPlayer.setDataSource(Native Method) 10-19 09:44:49.056: WARN/System.err(4654):     at ru.osiris.BusAdvertising.BusAdvertisingActivity.onCompletion(BusAdvertisingActivity.java:1255) 10-19 09:44:49.056: WARN/System.err(4654):     at android.media.MediaPlayer$EventHandler.handleMessage(MediaPlayer.java:1304) 10-19 09:44:49.056: WARN/System.err(4654):     at android.os.Handler.dispatchMessage(Handler.java:99) 10-19 09:44:49.056: WARN/System.err(4654):     at android.os.Looper.loop(Looper.java:123) 10-19 09:44:49.056: WARN/System.err(4654):     at android.app.ActivityThread.main(ActivityThread.java:4627) 10-19 09:44:49.056: WARN/System.err(4654):     at java.lang.reflect.Method.invokeNative(Native Method) 10-19 09:44:49.056: WARN/System.err(4654):     at java.lang.reflect.Method.invoke(Method.java:521) 10-19 09:44:49.056: WARN/System.err(4654):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 10-19 09:44:49.056: WARN/System.err(4654):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 10-19 09:44:49.056: WARN/System.err(4654):     at dalvik.system.NativeStart.main(Native Method) 

what does it mean? How can I fix it? there is my code:

public class BusAdvertisingActivity extends Activity implements LocationListener, OnBufferingUpdateListener, OnCompletionListener, OnPreparedListener, OnVideoSizeChangedListener, SurfaceHolder.Callback { ...     private MediaPlayer mMediaPlayer;     private SurfaceView mPreview;     private SurfaceHolder holder;     private String path;     private Bundle extras;       @Override     public void onCreate(Bundle icicle) {         mPreview = (SurfaceView) findViewById(R.id.surface);         holder = mPreview.getHolder();         holder.addCallback(this);         holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);         extras = getIntent().getExtras();     }  public void surfaceCreated(SurfaceHolder holder) {         Log.d(TAG, "surfaceCreated called");         playVideo(); } private void playVideo(Integer Media) {         Log.d(TAG, "playVideo called");         doCleanUp();         try {            File clip=new File(Environment.getExternalStorageDirectory(),                             playList[FLcurrentVideo].substring(2,            playList[FLcurrentVideo].length()-1)+".mp4");            path = clip.getAbsolutePath();            mMediaPlayer = new MediaPlayer();             mMediaPlayer.setDataSource(path);             mMediaPlayer.setDisplay(holder);             mMediaPlayer.prepare();             mMediaPlayer.setOnBufferingUpdateListener(this);             mMediaPlayer.setOnCompletionListener(this);             mMediaPlayer.setOnPreparedListener(this);             mMediaPlayer.setOnVideoSizeChangedListener(this);             mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);           } catch (Exception e) {             Log.e(TAG, "error: " + e.getMessage(), e);         }     }   public void onCompletion(MediaPlayer arg0) {          Log.d(TAG, "onCompletion called");         FLcurrentVideo++;          File clip=new File(Environment.getExternalStorageDirectory(),                 playList[FLcurrentVideo].substring(2, playList[FLcurrentVideo].length()-1)+".mp4");                 path = clip.getAbsolutePath();                      try {                         Log.d ("111", path);                         arg0.setDataSource(clip.getAbsolutePath());   //I got exception here                         arg0.setDisplay(holder);                         arg0.prepare();                         arg0.setOnBufferingUpdateListener(this);                         arg0.setOnCompletionListener(this);                         arg0.setOnPreparedListener(this);                         arg0.setOnVideoSizeChangedListener(this);                         arg0.setAudioStreamType(AudioManager.STREAM_MUSIC);                     } catch (IllegalArgumentException e) {                         // TODO Auto-generated catch block                         e.printStackTrace();                     } catch (IllegalStateException e) {                         // TODO Auto-generated catch block                         e.printStackTrace();                     } catch (IOException e) {                         // TODO Auto-generated catch block                         e.printStackTrace();                     }        } 

Please, help me.

Answer 1

If you see this state diagram (taken from https://developer.android.com/reference/android/media/MediaPlayer.html#StateDiagram):

You will realize that you should call reset() to get it back to the idle state. Only then can you call setDataSource()