Seek to specified time position with MediaPlayer - seekTo()

The method seekTo(int msec) of MediaPlayer seeks to specified time position.

Modify AndroidPlayerActivity.java from last exercise "Display playing time for MediaPlayer", implement OnSeekBarChangeListener of the SeekBar timeLine, and cmdSeekTo() method to call mediaPlayer.seekTo()

package com.exercise.AndroidPlayer;

import java.io.IOException;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnErrorListener;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidPlayerActivity extends Activity {
 
 TextView info, state;
 Button buttonOpen;
 Button buttonPlay, buttonPause, buttonStop;
 SeekBar timeLine;
 LinearLayout timeFrame;
 TextView timePos, timeDur;
 
 final static int RQS_OPEN_AUDIO_MP3 = 1;
 
 MediaPlayer mediaPlayer;
 String srcPath = null;
 enum MP_State {
     Idle, Initialized, Prepared, Started, Paused, 
     Stopped, PlaybackCompleted, End, Error, Preparing}
     
 MP_State mediaPlayerState;
 
 //ScheduledExecutorService myScheduledExecutorService;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        buttonOpen = (Button)findViewById(R.id.open);
        buttonOpen.setOnClickListener(buttonOpenOnClickListener);
        
        info = (TextView)findViewById(R.id.info);
        state = (TextView)findViewById(R.id.state);
        
        buttonPlay = (Button)findViewById(R.id.play);
        buttonPlay.setOnClickListener(buttonPlayOnClickListener);
        buttonPause = (Button)findViewById(R.id.pause);
        buttonPause.setOnClickListener(buttonPauseOnClickListener);
        buttonStop = (Button)findViewById(R.id.stop);
        buttonStop.setOnClickListener(buttonStopOnClickListener);
        
        //
        timeLine = (SeekBar)findViewById(R.id.seekbartimeline);
        timeFrame = (LinearLayout)findViewById(R.id.timeframe);
     timePos = (TextView)findViewById(R.id.pos);
     timeDur = (TextView)findViewById(R.id.dur);
     
        ScheduledExecutorService myScheduledExecutorService = Executors.newScheduledThreadPool(1);
        
        myScheduledExecutorService.scheduleWithFixedDelay(
          new Runnable(){
     @Override
     public void run() {
      monitorHandler.sendMessage(monitorHandler.obtainMessage());
     }}, 
          200, //initialDelay
          200, //delay
          TimeUnit.MILLISECONDS);
        
        timeLine.setOnSeekBarChangeListener(timeLineChangeListener);
        
    }
    
    OnSeekBarChangeListener timeLineChangeListener
    = new OnSeekBarChangeListener(){

  @Override
  public void onProgressChanged(SeekBar seekbar, int progress, boolean fromUser) {
   if(fromUser){
    cmdSeekTo(progress);
   }
   
  }

  @Override
  public void onStartTrackingTouch(SeekBar seekBar) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onStopTrackingTouch(SeekBar seekBar) {
   // TODO Auto-generated method stub
   
  }};
    
    Handler monitorHandler = new Handler(){

  @Override
  public void handleMessage(Message msg) {
   mediaPlayerMonitor();
  }
     
    };
    
    private void mediaPlayerMonitor(){
     if (mediaPlayer == null){
      timeLine.setVisibility(View.INVISIBLE);
      timeFrame.setVisibility(View.INVISIBLE);
     }else{
      if(mediaPlayer.isPlaying()){
       timeLine.setVisibility(View.VISIBLE);
          timeFrame.setVisibility(View.VISIBLE);
          
       int mediaDuration = mediaPlayer.getDuration();
       int mediaPosition = mediaPlayer.getCurrentPosition();
       timeLine.setMax(mediaDuration);
       timeLine.setProgress(mediaPosition);
       timePos.setText(String.valueOf((float)mediaPosition/1000) + "s");
          timeDur.setText(String.valueOf((float)mediaDuration/1000) + "s");
      }else{
       timeLine.setVisibility(View.INVISIBLE);
          timeFrame.setVisibility(View.INVISIBLE);
      }
     }
    }
    
    OnErrorListener mediaPlayerOnErrorListener
    = new OnErrorListener(){

  @Override
  public boolean onError(MediaPlayer mp, int what, int extra) {
   // TODO Auto-generated method stub
   
   mediaPlayerState = MP_State.Error;
   showMediaPlayerState();
   
   return false;
  }};
    
    
    private void cmdReset(){
     if (mediaPlayer == null){
      mediaPlayer = new MediaPlayer();
      mediaPlayer.setOnErrorListener(mediaPlayerOnErrorListener);
     }
     mediaPlayer.reset();
        mediaPlayerState = MP_State.Idle;
        showMediaPlayerState();
    }
    
    private void cmdSetDataSource(String path){
     if(mediaPlayerState == MP_State.Idle){
      try {
       mediaPlayer.setDataSource(path);
       mediaPlayerState = MP_State.Initialized;
      } catch (IllegalArgumentException e) {
       Toast.makeText(AndroidPlayerActivity.this, 
         e.toString(), Toast.LENGTH_LONG).show();
       e.printStackTrace();
      } catch (IllegalStateException e) {
       Toast.makeText(AndroidPlayerActivity.this, 
         e.toString(), Toast.LENGTH_LONG).show();
       e.printStackTrace();
      } catch (IOException e) {
       Toast.makeText(AndroidPlayerActivity.this, 
         e.toString(), Toast.LENGTH_LONG).show();
       e.printStackTrace();
      }
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdSetDataSource - skip", 
     Toast.LENGTH_LONG).show();
     }

     showMediaPlayerState();
    }
    
    private void cmdPrepare(){
     
     if(mediaPlayerState == MP_State.Initialized
      ||mediaPlayerState == MP_State.Stopped){
      try {
       mediaPlayer.prepare();
       mediaPlayerState = MP_State.Prepared;
      } catch (IllegalStateException e) {
       Toast.makeText(AndroidPlayerActivity.this, 
         e.toString(), Toast.LENGTH_LONG).show();
       e.printStackTrace();
      } catch (IOException e) {
       Toast.makeText(AndroidPlayerActivity.this, 
         e.toString(), Toast.LENGTH_LONG).show();
       e.printStackTrace();
      }
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdPrepare() - skip", 
     Toast.LENGTH_LONG).show();
     }

     showMediaPlayerState();
    }
    
    private void cmdStart(){
     if(mediaPlayerState == MP_State.Prepared
          ||mediaPlayerState == MP_State.Started
          ||mediaPlayerState == MP_State.Paused
          ||mediaPlayerState == MP_State.PlaybackCompleted){
      mediaPlayer.start();
      mediaPlayerState = MP_State.Started;
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdStart() - skip", 
     Toast.LENGTH_LONG).show();
     }

  showMediaPlayerState();
    }
    
    private void cmdPause(){
     if(mediaPlayerState == MP_State.Started
          ||mediaPlayerState == MP_State.Paused){
      mediaPlayer.pause();
      mediaPlayerState = MP_State.Paused;
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdPause() - skip", 
     Toast.LENGTH_LONG).show();
     }
  showMediaPlayerState();
    }
    
    private void cmdStop(){
  
  if(mediaPlayerState == MP_State.Prepared
    ||mediaPlayerState == MP_State.Started
    ||mediaPlayerState == MP_State.Stopped
          ||mediaPlayerState == MP_State.Paused
          ||mediaPlayerState == MP_State.PlaybackCompleted){
   mediaPlayer.stop();
   mediaPlayerState = MP_State.Stopped;
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdStop() - skip", 
     Toast.LENGTH_LONG).show();
     }
  showMediaPlayerState();

    }
    
    private void cmdSeekTo(int msec){
     if(mediaPlayerState == MP_State.Prepared
       ||mediaPlayerState == MP_State.Started
       ||mediaPlayerState == MP_State.Paused
       ||mediaPlayerState == MP_State.PlaybackCompleted){
      mediaPlayer.seekTo(msec);
     }else{
      Toast.makeText(AndroidPlayerActivity.this, 
     "Invalid State@cmdSeekTo() - skip", 
     Toast.LENGTH_LONG).show();
     }
     showMediaPlayerState();
    }
    
    private void showMediaPlayerState(){
     
     switch(mediaPlayerState){
     case Idle:
      state.setText("Idle");
      break;
     case Initialized:
      state.setText("Initialized");
      break;
     case Prepared:
      state.setText("Prepared");
      break;
     case Started:
      state.setText("Started");
      break;
     case Paused:
      state.setText("Paused");
      break;
     case Stopped:
      state.setText("Stopped");
      break;
     case PlaybackCompleted:
      state.setText("PlaybackCompleted");
      break;
     case End:
      state.setText("End");
      break;
     case Error:
      state.setText("Error");
      break;
     case Preparing:
      state.setText("Preparing");
      break;
     default:
      state.setText("Unknown!");
     }
    }
    
    OnClickListener buttonPlayOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View v) {
   
   if(srcPath == null){
    Toast.makeText(AndroidPlayerActivity.this, 
      "No file selected", 
      Toast.LENGTH_LONG).show();
   }else{
    cmdPrepare();
    cmdStart();
   }

  }
     
    };
    
    OnClickListener buttonPauseOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View v) {
   cmdPause();
  }
     
    };
    
    OnClickListener buttonStopOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View v) {
   
   cmdStop();
   
  }
     
    };
    
    OnClickListener buttonOpenOnClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View arg0) {
   Intent intent = new Intent();
   intent.setType("audio/mp3");
   intent.setAction(Intent.ACTION_GET_CONTENT);
   startActivityForResult(Intent.createChooser(
     intent, "Open Audio (mp3) file"), RQS_OPEN_AUDIO_MP3);

  } 
    };

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  if (resultCode == RESULT_OK) {
   if (requestCode == RQS_OPEN_AUDIO_MP3) {
    Uri audioFileUri = data.getData();
    
    srcPath = audioFileUri.getPath();
    info.setText(srcPath);
    
    cmdReset();
    cmdSetDataSource(srcPath);

   } 
  } 
 }

}

Download the files.