How to resume MediaPlayer in Android after pressing the home button and reopen the app

I tried a lot of methods, I made a lot of changes on my code, I read Android MediaPlayer document, I tried StackOverflow examples but none of them could solve my problem.

My problem: When I press the home button of emulator or phone then reopen the app it is starting from the beginning.

Hope you can help me. Thanks in advance.

Here is my code :

public class Mediaplayer extends Activity implements OnCompletionListener,
    OnErrorListener, OnInfoListener, OnPreparedListener,
    OnSeekCompleteListener, OnVideoSizeChangedListener,
    SurfaceHolder.Callback, MediaController.MediaPlayerControl {
Display currentDisplay;
SurfaceView surfaceView;
SurfaceHolder surfaceHolder;
MediaPlayer mediaPlayer;
MediaController controller;
int videoWidth = 0;
int videoHeight = 0;
boolean readyToPlay = false;
public final static String LOGTAG = "CUSTOM_VIDEO_PLAYER";

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.video);

    surfaceView = (SurfaceView) this.findViewById(R.id.SurfaceView);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    mediaPlayer = new MediaPlayer();
    mediaPlayer.setOnCompletionListener(this);
    mediaPlayer.setOnErrorListener(this);
    mediaPlayer.setOnInfoListener(this);
    mediaPlayer.setOnPreparedListener(this);
    mediaPlayer.setOnSeekCompleteListener(this);
    mediaPlayer.setOnVideoSizeChangedListener(this);
    mediaPlayer.setWakeMode(getApplicationContext(),
            PowerManager.PARTIAL_WAKE_LOCK);
    String filePath = "http://cdn.example.com/wp-content/uploads/Almost.Human-S01E10.mp4";

    try {
        mediaPlayer.setDataSource(filePath);
    } catch (IllegalArgumentException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IllegalStateException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IOException e) {
        Log.v(LOGTAG, e.getMessage());
        finish();
    }

    controller = new MediaController(this);
    currentDisplay = getWindowManager().getDefaultDisplay();

}

public void surfaceCreated(SurfaceHolder holder) {
    // Log.v(LOGTAG, "surfaceCreated Called");

    mediaPlayer.setDisplay(holder);

    try {
        mediaPlayer.prepare();
    } catch (IllegalStateException e) {
        // Log.v(LOGTAG, e.getMessage());
        finish();
    } catch (IOException e) {
        // Log.v(LOGTAG, e.getMessage());
        finish();
    }
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    Log.v(LOGTAG, "surfaceChanged Called");
}

public void surfaceDestroyed(SurfaceHolder holder) {
    Log.v(LOGTAG, "surfaceDestroyed Called");
}

public void onCompletion(MediaPlayer mp) {
    Log.v(LOGTAG, "onCompletion Called");
    finish();
}

public boolean onError(MediaPlayer mp, int whatError, int extra) {
    Log.v(LOGTAG, "onError Called");

    if (whatError == MediaPlayer.MEDIA_ERROR_SERVER_DIED) {
        Log.v(LOGTAG, "Media Error, Server Died " + extra);
    } else if (whatError == MediaPlayer.MEDIA_ERROR_UNKNOWN) {
        Log.v(LOGTAG, "Media Error, Error Unknown " + extra);
    }

    return false;
}

public boolean onInfo(MediaPlayer mp, int whatInfo, int extra) {
    if (whatInfo == MediaPlayer.MEDIA_INFO_BAD_INTERLEAVING) {
        Log.v(LOGTAG, "Media Info, Media Info Bad Interleaving " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_NOT_SEEKABLE) {
        Log.v(LOGTAG, "Media Info, Media Info Not Seekable " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_UNKNOWN) {
        Log.v(LOGTAG, "Media Info, Media Info Unknown " + extra);
    } else if (whatInfo == MediaPlayer.MEDIA_INFO_VIDEO_TRACK_LAGGING) {
        Log.v(LOGTAG, "MediaInfo, Media Info Video Track Lagging " + extra);
        /*
         * Android Version 2.0 and Higher } else if (whatInfo ==
         * MediaPlayer.MEDIA_INFO_METADATA_UPDATE) {
         * Log.v(LOGTAG,"MediaInfo, Media Info Metadata Update " + extra);
         */
    }
    return false;
}

public void onPrepared(MediaPlayer mp) {
    Log.v(LOGTAG, "onPrepared Called");
    videoWidth = mp.getVideoWidth();
    videoHeight = mp.getVideoHeight();

    if (videoWidth > currentDisplay.getWidth()
            || videoHeight > currentDisplay.getHeight()) {
        float heightRatio = (float) videoHeight
                / (float) currentDisplay.getHeight();
        float widthRatio = (float) videoWidth
                / (float) currentDisplay.getWidth();

        if (heightRatio > 1 || widthRatio > 1) {
            if (heightRatio > widthRatio) {
                videoHeight = (int) Math.ceil((float) videoHeight
                        / (float) heightRatio);
                videoWidth = (int) Math.ceil((float) videoWidth
                        / (float) heightRatio);
            } else {
                videoHeight = (int) Math.ceil((float) videoHeight
                        / (float) widthRatio);
                videoWidth = (int) Math.ceil((float) videoWidth
                        / (float) widthRatio);
            }
        }
    }

    surfaceView.setLayoutParams(new LinearLayout.LayoutParams(videoWidth,
            videoHeight));
    mp.start();

    controller.setMediaPlayer(this);
    controller.setAnchorView(this.findViewById(R.id.MainView));
    controller.setEnabled(true);
    controller.show();
}

@Override
protected void onPause() {
    super.onPause();
    if (mediaPlayer.isPlaying()) {
        mediaPlayer.pause();
    } else {
        return;
    }
}

public void onSeekComplete(MediaPlayer mp) {
    Log.v(LOGTAG, "onSeekComplete Called");
}

public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
    Log.v(LOGTAG, "onVideoSizeChanged Called");
}

public boolean canPause() {
    return true;
}

public boolean canSeekBackward() {
    return true;
}

public boolean canSeekForward() {
    return true;
}

public int getBufferPercentage() {
    return 0;
}

public int getCurrentPosition() {
    return mediaPlayer.getCurrentPosition();
}

public int getDuration() {
    return mediaPlayer.getDuration();
}

public boolean isPlaying() {
    return mediaPlayer.isPlaying();
}

public void pause() {

    mediaPlayer.pause();

}

public void seekTo(int pos) {
    mediaPlayer.seekTo(pos);
}

public void start() {
    mediaPlayer.start();
}

@Override
public boolean onTouchEvent(MotionEvent ev) {

    controller.show();

    return false;
}

@Override
public int getAudioSessionId() {
    // TODO Auto-generated method stub
    return 0;
}

 }