Why my app can't read Internal storage

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    package="com.playmusic.ghufron"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk>
        android:minSdkVersion="9"
        android:targetSdkVersion="19" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    
    

    <application>
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity>
            android:name="com.playmusic.ghufron.MainActivity"
            android:label="@string/app_name" 
            android:launchMode="singleTop"
            android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <service android:name="com.playmusic.ghufron.MusicService" />
            
       
    </application>

</uses-sdk></manifest>

package com.playmusic.ghufron;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;

import com.playmusic.ghufron.MusicService.MusicBinder;



import android.net.Uri;
import android.os.Bundle;
import android.os.IBinder;
import android.app.Activity;
import android.content.ComponentName;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.database.Cursor;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.MediaController.MediaPlayerControl;



public class MainActivity extends Activity implements MediaPlayerControl {

	//song list variables
	private ArrayList<song> songList;
	private ListView songView;

	//service
	private MusicService musicSrv;
	private Intent playIntent;
	//binding
	private boolean musicBound=false;

	//controller
	private MusicController controller;

	//activity and playback pause flags
	private boolean paused=false, playbackPaused=false;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		//retrieve list view
		songView = (ListView)findViewById(R.id.song_list);
		//instantiate list
		songList = new ArrayList<song>();
		//get songs from device
		getSongList();
		//sort alphabetically by title
		Collections.sort(songList, new Comparator<song>(){
			public int compare(Song a, Song b){
				return a.getTitle().compareTo(b.getTitle());
			}
		});
		//create and set adapter
		SongAdapter songAdt = new SongAdapter(this, songList);
		songView.setAdapter(songAdt);

		//setup controller
		setController();
	}

	//connect to the service
	private ServiceConnection musicConnection = new ServiceConnection(){

		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			MusicBinder binder = (MusicBinder)service;
			//get service
			musicSrv = binder.getService();
			//pass list
			musicSrv.setList(songList);
			musicBound = true;
		}

		@Override
		public void onServiceDisconnected(ComponentName name) {
			musicBound = false;
		}
	};

	//start and bind the service when the activity starts
	@Override
	protected void onStart() {
		super.onStart();
		if(playIntent==null){
			playIntent = new Intent(this, MusicService.class);
			bindService(playIntent, musicConnection, Context.BIND_AUTO_CREATE);
			startService(playIntent);
		}
	}

	//user song select
	public void songPicked(View view){
		musicSrv.setSong(Integer.parseInt(view.getTag().toString()));
		musicSrv.playSong();
		if(playbackPaused){
			setController();
			playbackPaused=false;
		}
		controller.show(0);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		//menu item selected
		switch (item.getItemId()) {
		case R.id.action_shuffle:
			musicSrv.setShuffle();
			break;
		case R.id.action_end:
			stopService(playIntent);
			musicSrv=null;
			System.exit(0);
			break;
		}
		return super.onOptionsItemSelected(item);
	}

	//method to retrieve song info from device
	public void getSongList(){
		//query external audio
		ContentResolver musicResolver = getContentResolver();
		Uri musicUri = android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
		Uri musicUri2= android.provider.MediaStore.Audio.Media.INTERNAL_CONTENT_URI;
	
		Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);
		Cursor musicCursor2 = musicResolver.query(musicUri, null, null, null, null);
		//iterate over results if valid
		if(musicCursor2!=null && musicCursor2.moveToFirst()){
			//get columns
			int titleColumn2 = musicCursor2.getColumnIndex
					(android.provider.MediaStore.Audio.Media.TITLE);
			int idColumn2 = musicCursor2.getColumnIndex
					(android.provider.MediaStore.Audio.Media._ID);
			int artistColumn2 = musicCursor2.getColumnIndex
					(android.provider.MediaStore.Audio.Media.ARTIST);
			//add songs to list
			do {
				long thisId = musicCursor2.getLong(idColumn2);
				String thisTitle = musicCursor2.getString(titleColumn2);
				String thisArtist = musicCursor2.getString(artistColumn2);
				songList.add(new Song(thisId, thisTitle, thisArtist));
			} 
			while (musicCursor.moveToNext());
		
		if(musicCursor!=null && musicCursor.moveToFirst()){
			//get columns
			int titleColumn = musicCursor.getColumnIndex
					(android.provider.MediaStore.Audio.Media.TITLE);
			int idColumn = musicCursor.getColumnIndex
					(android.provider.MediaStore.Audio.Media._ID);
			int artistColumn = musicCursor.getColumnIndex
					(android.provider.MediaStore.Audio.Media.ARTIST);
			//add songs to list
			do {
				long thisId = musicCursor.getLong(idColumn);
				String thisTitle = musicCursor.getString(titleColumn);
				String thisArtist = musicCursor.getString(artistColumn);
				songList.add(new Song(thisId, thisTitle, thisArtist));
			} 
			while (musicCursor.moveToNext());
		}}
	}

	@Override
	public boolean canPause() {
		return true;
	}

	@Override
	public boolean canSeekBackward() {
		return true;
	}

	@Override
	public boolean canSeekForward() {
		return true;
	}

	@Override
	public int getAudioSessionId() {
		return 0;
	}

	@Override
	public int getBufferPercentage() {
		return 0;
	}

	@Override
	public int getCurrentPosition() {
		if(musicSrv!=null && musicBound && musicSrv.isPng())
			return musicSrv.getPosn();
		else return 0;
	}

	@Override
	public int getDuration() {
		if(musicSrv!=null && musicBound && musicSrv.isPng())
			return musicSrv.getDur();
		else return 0;
	}

	@Override
	public boolean isPlaying() {
		if(musicSrv!=null && musicBound)
			return musicSrv.isPng();
		return false;
	}

	@Override
	public void pause() {
		playbackPaused=true;
		musicSrv.pausePlayer();
	}

	@Override
	public void seekTo(int pos) {
		musicSrv.seek(pos);
	}

	@Override
	public void start() {
		musicSrv.go();
	}

	//set the controller up
	private void setController(){
		controller = new MusicController(this);
		//set previous and next button listeners
		controller.setPrevNextListeners(new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				playNext();
			}
		}, new View.OnClickListener() {
			@Override
			public void onClick(View v) {
				playPrev();
			}
		});
		//set and show
		controller.setMediaPlayer(this);
		controller.setAnchorView(findViewById(R.id.song_list));
		controller.setEnabled(true);
	}

	private void playNext(){
		musicSrv.playNext();
		if(playbackPaused){ 
			setController();
			playbackPaused=false;
		}
		controller.show(0);
	}

	private void playPrev(){
		musicSrv.playPrev();
		if(playbackPaused){
			setController();
			playbackPaused=false;
		}
		controller.show(0);
	}

	@Override
	protected void onPause(){
		super.onPause();
		paused=true;
	}

	@Override
	protected void onResume(){
		super.onResume();
		if(paused){
			setController();
			paused=false;
		}
	}

	@Override
	protected void onStop() {
		controller.hide();
		super.onStop();
	}

	@Override
	protected void onDestroy() {
		stopService(playIntent);
		musicSrv=null;
		super.onDestroy();
	}

}

W/dalvikvm(22608): VFY: unable to resolve virtual method 163: Landroid/app/Notification$Builder;.build ()Landroid/app/Notification;<br />
I/Adreno200-EGLSUB(22608): <configwindowmatch:2081 xmlns:configwindowmatch="#unknown">: Format RGBA_8888.<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x51e75000 size:3702784 offset:3088384 fd:69<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x52356000 size:614400 offset:0 fd:74<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x52516000 size:1228800 offset:614400 fd:77<br />
E/MediaPlayer(22608): Uri is  content://media/external/audio/media/45<br />
D/MediaPlayer(22608): http youtube = false, scheme = content<br />
E/MediaPlayer(22608): Uri is  content://media/internal/audio/media/45<br />
D/MediaPlayer(22608): http youtube = false, scheme = content<br />
E/MediaPlayer(22608): attachNewPlayer called in state 2<br />
E/MUSIC SERVICE(22608): Error setting data source<br />
E/MUSIC SERVICE(22608): java.lang.IllegalStateException<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(Native Method)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:1000)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:863)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:812)<br />
E/MUSIC SERVICE(22608): 	at com.playmusic.ghufron.MusicService.playSong(MusicService.java:109)<br />
E/MUSIC SERVICE(22608): 	at com.playmusic.ghufron.MainActivity.songPicked(MainActivity.java:105)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invokeNative(Native Method)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invoke(Method.java:511)<br />
E/MUSIC SERVICE(22608): 	at android.view.View$1.onClick(View.java:3052)<br />
E/MUSIC SERVICE(22608): 	at android.view.View.performClick(View.java:3528)<br />
E/MUSIC SERVICE(22608): 	at android.view.View$PerformClick.run(View.java:14235)<br />
E/MUSIC SERVICE(22608): 	at android.os.Handler.handleCallback(Handler.java:605)<br />
E/MUSIC SERVICE(22608): 	at android.os.Handler.dispatchMessage(Handler.java:92)<br />
E/MUSIC SERVICE(22608): 	at android.os.Looper.loop(Looper.java:137)<br />
E/MUSIC SERVICE(22608): 	at android.app.ActivityThread.main(ActivityThread.java:4424)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invokeNative(Native Method)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invoke(Method.java:511)<br />
E/MUSIC SERVICE(22608): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:817)<br />
E/MUSIC SERVICE(22608): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)<br />
E/MUSIC SERVICE(22608): 	at dalvik.system.NativeStart.main(Native Method)<br />
D/MediaPlayer(22608): start() mUri is content://media/internal/audio/media/45<br />
I/Adreno200-EGLSUB(22608): <configwindowmatch:2081>: Format RGBA_8888.<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x52742000 size:2670592 offset:2547712 fd:80<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x52a0e000 size:2904064 offset:2781184 fd:86<br />
D/memalloc(22608): /dev/pmem: Mapped buffer base:0x52cd3000 size:3026944 offset:2904064 fd:89<br />
E/MediaPlayer(22608): Uri is  content://media/external/audio/media/45<br />
D/MediaPlayer(22608): http youtube = false, scheme = content<br />
E/MediaPlayer(22608): Uri is  content://media/internal/audio/media/45<br />
D/MediaPlayer(22608): http youtube = false, scheme = content<br />
E/MediaPlayer(22608): attachNewPlayer called in state 2<br />
E/MUSIC SERVICE(22608): Error setting data source<br />
E/MUSIC SERVICE(22608): java.lang.IllegalStateException<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(Native Method)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:1000)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:863)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer.setDataSource(MediaPlayer.java:812)<br />
E/MUSIC SERVICE(22608): 	at com.playmusic.ghufron.MusicService.playSong(MusicService.java:109)<br />
E/MUSIC SERVICE(22608): 	at com.playmusic.ghufron.MusicService.playNext(MusicService.java:209)<br />
E/MUSIC SERVICE(22608): 	at com.playmusic.ghufron.MusicService.onCompletion(MusicService.java:127)<br />
E/MUSIC SERVICE(22608): 	at android.media.MediaPlayer$EventHandler.handleMessage(MediaPlayer.java:1763)<br />
E/MUSIC SERVICE(22608): 	at android.os.Handler.dispatchMessage(Handler.java:99)<br />
E/MUSIC SERVICE(22608): 	at android.os.Looper.loop(Looper.java:137)<br />
E/MUSIC SERVICE(22608): 	at android.app.ActivityThread.main(ActivityThread.java:4424)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invokeNative(Native Method)<br />
E/MUSIC SERVICE(22608): 	at java.lang.reflect.Method.invoke(Method.java:511)<br />
E/MUSIC SERVICE(22608): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:817)<br />
E/MUSIC SERVICE(22608): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)<br />
E/MUSIC SERVICE(22608): 	at dalvik.system.NativeStart.main(Native Method)<br />
D/MediaPlayer(22608): start() mUri is content://media/internal/audio/media/45<br />
D/MediaPlayer(22608): pause() mUri is content://media/internal/audio/media/45<br />
<br />

package com.playmusic.ghufron;

import java.util.ArrayList;
import java.util.Random;

import android.app.Notification;
import android.app.PendingIntent;
import android.app.Service;
import android.content.ContentUris;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Binder;
import android.os.IBinder;
import android.os.PowerManager;
import android.util.Log;



public class MusicService extends Service implements 
MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener,
MediaPlayer.OnCompletionListener {

	//media player
	private MediaPlayer player;
	//song list
	private ArrayList<song> songs;
	//current position
	private int songPosn;
	//binder
	private final IBinder musicBind = new MusicBinder();
	//title of current song
	private String songTitle="";
	//notification id
	private static final int NOTIFY_ID=1;
	//shuffle flag and random
	private boolean shuffle=false;
	private Random rand;

	public void onCreate(){
		//create the service
		super.onCreate();
		//initialize position
		songPosn=0;
		//random
		rand=new Random();
		//create player
		player = new MediaPlayer();
		//initialize
		initMusicPlayer();
	}

	public void initMusicPlayer(){
		//set player properties
		player.setWakeMode(getApplicationContext(), 
				PowerManager.PARTIAL_WAKE_LOCK);
		player.setAudioStreamType(AudioManager.STREAM_MUSIC);
		//set listeners
		player.setOnPreparedListener(this);
		player.setOnCompletionListener(this);
		player.setOnErrorListener(this);
	}

	//pass song list
	public void setList(ArrayList<song> theSongs){
		songs=theSongs;
	}

	//binder
	public class MusicBinder extends Binder {
		MusicService getService() { 
			return MusicService.this;
		}
	}

	//activity will bind to service
	@Override
	public IBinder onBind(Intent intent) {
		return musicBind;
	}

	//release resources when unbind
	@Override
	public boolean onUnbind(Intent intent){
		player.stop();
		player.release();
		return false;
	}

	//play a song
	public void playSong(){
		//play
		player.reset();
		//get song
		Song playSong = songs.get(songPosn);
		//get title
		songTitle=playSong.getTitle();
		//get id
		long currSong = playSong.getID();
		//set uri
		Uri trackUri = ContentUris.withAppendedId(
				android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
				currSong);
		Uri trackUri2 = ContentUris.withAppendedId(android.provider.MediaStore.Audio.Media.INTERNAL_CONTENT_URI,currSong);
		//set the data source
		try{ 
			player.setDataSource(getApplicationContext(), trackUri);
			player.setDataSource(getApplicationContext(),trackUri2);
		}
		catch(Exception e){
			Log.e("MUSIC SERVICE", "Error setting data source", e);
		}
		player.prepareAsync(); 
	}

	//set the song
	public void setSong(int songIndex){
		songPosn=songIndex;	
	}

	@Override
	public void onCompletion(MediaPlayer mp) {
		//check if playback has reached the end of a track
		if(player.getCurrentPosition()>0){
			mp.reset();
			playNext();
		}
	}

	@Override
	public boolean onError(MediaPlayer mp, int what, int extra) {
		Log.v("MUSIC PLAYER", "Playback Error");
		mp.reset();
		return false;
	}

	@SuppressWarnings("deprecation")
	@Override
	public void onPrepared(MediaPlayer mp) {
		//start playback
		mp.start();
		//notification
		Intent notIntent = new Intent(this, MainActivity.class);
		notIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
		PendingIntent pendInt = PendingIntent.getActivity(this, 0,
				notIntent, PendingIntent.FLAG_UPDATE_CURRENT);

		Notification.Builder builder = new Notification.Builder(this);

		builder.setContentIntent(pendInt)
		.setSmallIcon(R.drawable.play)
		.setTicker(songTitle)
		.setOngoing(true)
		.setContentTitle("Playing")
		.setContentText(songTitle);
		Notification ya =
			    (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN) ?
			        builder.build() : builder.getNotification();
		startForeground(NOTIFY_ID, ya);
		
	}

	//playback methods
	public int getPosn(){
		return player.getCurrentPosition();
	}

	public int getDur(){
		return player.getDuration();
	}

	public boolean isPng(){
		return player.isPlaying();
	}

	public void pausePlayer(){
		player.pause();
	}

	public void seek(int posn){
		player.seekTo(posn);
	}

	public void go(){
		player.start();
	}

	//skip to previous track
	public void playPrev(){
		songPosn--;
		if(songPosn<0) songPosn=songs.size()-1;
		playSong();
	}

	//skip to next
	public void playNext(){
		if(shuffle){
			int newSong = songPosn;
			while(newSong==songPosn){
				newSong=rand.nextInt(songs.size());
			}
			songPosn=newSong;
		}
		else{
			songPosn++;
			if(songPosn>=songs.size()) songPosn=0;
		}
		playSong();
	}

	@Override
	public void onDestroy() {
		stopForeground(true);
	}

	//toggle shuffle
	public void setShuffle(){
		if(shuffle) shuffle=false;
		else shuffle=true;
	}

}