Android 如何使用emulator测试媒体播放器并播放声音文件？

使用AndroidMediaPlayer并将歌曲管理器的

媒体路径设置为
“/sdcard/”
。
我正在使用emulator运行应用程序，但出现以下异常

08-17 05:54:00.618: E/AndroidRuntime(829): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.androidhive.musicplayer/com.androidhive.musicplayer.MusicPlayerActivity}: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0

启动emulator时，控制台中出现以下错误

[2013-08-17 11:49:06 - MusicPlayer] Failed to install MusicPlayer.apk on device 'emulator-5554!
[2013-08-17 11:49:06 - MusicPlayer] (null)
[2013-08-17 11:49:08 - MusicPlayer] Launch canceled!

以下是主要音乐播放器活动的代码

package com.androidhive.musicplayer;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Random;

import android.app.Activity;
import android.content.Intent;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.ImageButton;
import android.widget.SeekBar;
import android.widget.TextView;
import android.widget.Toast;

public class AndroidBuildingMusicPlayerActivity extends Activity implements OnCompletionListener, SeekBar.OnSeekBarChangeListener {

    private ImageButton btnPlay;
    private ImageButton btnForward;
    private ImageButton btnBackward;
    private ImageButton btnNext;
    private ImageButton btnPrevious;
    private ImageButton btnPlaylist;
    private ImageButton btnRepeat;
    private ImageButton btnShuffle;
    private SeekBar songProgressBar;
    private TextView songTitleLabel;
    private TextView songCurrentDurationLabel;
    private TextView songTotalDurationLabel;
    // Media Player
    private  MediaPlayer mp;
    // Handler to update UI timer, progress bar etc,.
    private Handler mHandler = new Handler();;
    private SongsManager songManager;
    private Utilities utils;
    private int seekForwardTime = 5000; // 5000 milliseconds
    private int seekBackwardTime = 5000; // 5000 milliseconds
    private int currentSongIndex = 0; 
    private boolean isShuffle = false;
    private boolean isRepeat = false;
    private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.player);

        // All player buttons
        btnPlay = (ImageButton) findViewById(R.id.btnPlay);
        btnForward = (ImageButton) findViewById(R.id.btnForward);
        btnBackward = (ImageButton) findViewById(R.id.btnBackward);
        btnNext = (ImageButton) findViewById(R.id.btnNext);
        btnPrevious = (ImageButton) findViewById(R.id.btnPrevious);
        btnPlaylist = (ImageButton) findViewById(R.id.btnPlaylist);
        btnRepeat = (ImageButton) findViewById(R.id.btnRepeat);
        btnShuffle = (ImageButton) findViewById(R.id.btnShuffle);
        songProgressBar = (SeekBar) findViewById(R.id.songProgressBar);
        songTitleLabel = (TextView) findViewById(R.id.songTitle);
        songCurrentDurationLabel = (TextView) findViewById(R.id.songCurrentDurationLabel);
        songTotalDurationLabel = (TextView) findViewById(R.id.songTotalDurationLabel);

        // Mediaplayer
        mp = new MediaPlayer();
        songManager = new SongsManager();
        utils = new Utilities();

        // Listeners
        songProgressBar.setOnSeekBarChangeListener(this); // Important
        mp.setOnCompletionListener(this); // Important

        // Getting all songs list
        songsList = songManager.getPlayList();

        // By default play first song
        playSong(0);

        /**
         * Play button click event
         * plays a song and changes button to pause image
         * pauses a song and changes button to play image
         * */
        btnPlay.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // check for already playing
                if(mp.isPlaying()){
                    if(mp!=null){
                        mp.pause();
                        // Changing button image to play button
                        btnPlay.setImageResource(R.drawable.btn_play);
                    }
                }else{
                    // Resume song
                    if(mp!=null){
                        mp.start();
                        // Changing button image to pause button
                        btnPlay.setImageResource(R.drawable.btn_pause);
                    }
                }

            }
        });

        /**
         * Forward button click event
         * Forwards song specified seconds
         * */
        btnForward.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // get current song position                
                int currentPosition = mp.getCurrentPosition();
                // check if seekForward time is lesser than song duration
                if(currentPosition + seekForwardTime <= mp.getDuration()){
                    // forward song
                    mp.seekTo(currentPosition + seekForwardTime);
                }else{
                    // forward to end position
                    mp.seekTo(mp.getDuration());
                }
            }
        });

        /**
         * Backward button click event
         * Backward song to specified seconds
         * */
        btnBackward.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // get current song position                
                int currentPosition = mp.getCurrentPosition();
                // check if seekBackward time is greater than 0 sec
                if(currentPosition - seekBackwardTime >= 0){
                    // forward song
                    mp.seekTo(currentPosition - seekBackwardTime);
                }else{
                    // backward to starting position
                    mp.seekTo(0);
                }

            }
        });

        /**
         * Next button click event
         * Plays next song by taking currentSongIndex + 1
         * */
        btnNext.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // check if next song is there or not
                if(currentSongIndex < (songsList.size() - 1)){
                    playSong(currentSongIndex + 1);
                    currentSongIndex = currentSongIndex + 1;
                }else{
                    // play first song
                    playSong(0);
                    currentSongIndex = 0;
                }

            }
        });

        /**
         * Back button click event
         * Plays previous song by currentSongIndex - 1
         * */
        btnPrevious.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if(currentSongIndex > 0){
                    playSong(currentSongIndex - 1);
                    currentSongIndex = currentSongIndex - 1;
                }else{
                    // play last song
                    playSong(songsList.size() - 1);
                    currentSongIndex = songsList.size() - 1;
                }

            }
        });

        /**
         * Button Click event for Repeat button
         * Enables repeat flag to true
         * */
        btnRepeat.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if(isRepeat){
                    isRepeat = false;
                    Toast.makeText(getApplicationContext(), "Repeat is OFF", Toast.LENGTH_SHORT).show();
                    btnRepeat.setImageResource(R.drawable.btn_repeat);
                }else{
                    // make repeat to true
                    isRepeat = true;
                    Toast.makeText(getApplicationContext(), "Repeat is ON", Toast.LENGTH_SHORT).show();
                    // make shuffle to false
                    isShuffle = false;
                    btnRepeat.setImageResource(R.drawable.btn_repeat_focused);
                    btnShuffle.setImageResource(R.drawable.btn_shuffle);
                }   
            }
        });

        /**
         * Button Click event for Shuffle button
         * Enables shuffle flag to true
         * */
        btnShuffle.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                if(isShuffle){
                    isShuffle = false;
                    Toast.makeText(getApplicationContext(), "Shuffle is OFF", Toast.LENGTH_SHORT).show();
                    btnShuffle.setImageResource(R.drawable.btn_shuffle);
                }else{
                    // make repeat to true
                    isShuffle= true;
                    Toast.makeText(getApplicationContext(), "Shuffle is ON", Toast.LENGTH_SHORT).show();
                    // make shuffle to false
                    isRepeat = false;
                    btnShuffle.setImageResource(R.drawable.btn_shuffle_focused);
                    btnRepeat.setImageResource(R.drawable.btn_repeat);
                }   
            }
        });

        /**
         * Button Click event for Play list click event
         * Launches list activity which displays list of songs
         * */
        btnPlaylist.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                Intent i = new Intent(getApplicationContext(), PlayListActivity.class);
                startActivityForResult(i, 100);         
            }
        });

    }

    /**
     * Receiving song index from playlist view
     * and play the song
     * */
    @Override
    protected void onActivityResult(int requestCode,
                                     int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(resultCode == 100){
             currentSongIndex = data.getExtras().getInt("songIndex");
             // play selected song
             playSong(currentSongIndex);
        }

    }

    /**
     * Function to play a song
     * @param songIndex - index of song
     * */
    public void  playSong(int songIndex){
        // Play song
        try {
            mp.reset();
            mp.setDataSource(songsList.get(songIndex).get("songPath"));
            mp.prepare();
            mp.start();
            // Displaying Song title
            String songTitle = songsList.get(songIndex).get("songTitle");
            songTitleLabel.setText(songTitle);

            // Changing Button Image to pause image
            btnPlay.setImageResource(R.drawable.btn_pause);

            // set Progress bar values
            songProgressBar.setProgress(0);
            songProgressBar.setMax(100);

            // Updating progress bar
            updateProgressBar();            
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Update timer on seekbar
     * */
    public void updateProgressBar() {
        mHandler.postDelayed(mUpdateTimeTask, 100);        
    }   

    /**
     * Background Runnable thread
     * */
    private Runnable mUpdateTimeTask = new Runnable() {
           @Override
        public void run() {
               long totalDuration = mp.getDuration();
               long currentDuration = mp.getCurrentPosition();

               // Displaying Total Duration time
               songTotalDurationLabel.setText(""+utils.milliSecondsToTimer(totalDuration));
               // Displaying time completed playing
               songCurrentDurationLabel.setText(""+utils.milliSecondsToTimer(currentDuration));

               // Updating progress bar
               int progress = (utils.getProgressPercentage(currentDuration, totalDuration));
               //Log.d("Progress", ""+progress);
               songProgressBar.setProgress(progress);

               // Running this thread after 100 milliseconds
               mHandler.postDelayed(this, 100);
           }
        };

    /**
     * 
     * */
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromTouch) {

    }

    /**
     * When user starts moving the progress handler
     * */
    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
        // remove message Handler from updating progress bar
        mHandler.removeCallbacks(mUpdateTimeTask);
    }

    /**
     * When user stops moving the progress hanlder
     * */
    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
        mHandler.removeCallbacks(mUpdateTimeTask);
        int totalDuration = mp.getDuration();
        int currentPosition = utils.progressToTimer(seekBar.getProgress(), totalDuration);

        // forward or backward to certain seconds
        mp.seekTo(currentPosition);

        // update timer progress again
        updateProgressBar();
    }

    /**
     * On Song Playing completed
     * if repeat is ON play same song again
     * if shuffle is ON play random song
     * */
    @Override
    public void onCompletion(MediaPlayer arg0) {

        // check for repeat is ON or OFF
        if(isRepeat){
            // repeat is on play same song again
            playSong(currentSongIndex);
        } else if(isShuffle){
            // shuffle is on - play a random song
            Random rand = new Random();
            currentSongIndex = rand.nextInt((songsList.size() - 1) - 0 + 1) + 0;
            playSong(currentSongIndex);
        } else{
            // no repeat or shuffle ON - play next song
            if(currentSongIndex < (songsList.size() - 1)){
                playSong(currentSongIndex + 1);
                currentSongIndex = currentSongIndex + 1;
            }else{
                // play first song
                playSong(0);
                currentSongIndex = 0;
            }
        }
    }

    @Override
     public void onDestroy(){
     super.onDestroy();
        mp.release();
     }

}

package com.androidhive.musicplayer；
导入java.io.IOException；
导入java.util.ArrayList；
导入java.util.HashMap；
导入java.util.Random；
导入android.app.Activity；
导入android.content.Intent；
导入android.media.MediaPlayer；
导入android.media.MediaPlayer.OnCompletionListener；
导入android.os.Bundle；
导入android.os.Handler；
导入android.view.view；
导入android.widget.ImageButton；
导入android.widget.SeekBar；
导入android.widget.TextView；
导入android.widget.Toast；
公共类AndroidBuildingMusicLayerActivity扩展了CompletionListener上的活动实现，请参见kbar.OnSeekBarChangeListener{
私人图像按钮btnPlay；
专用图像按钮btnForward；
私人图像按钮btnBackward；
私有图像按钮btnNext；
私人图像按钮b先前；
私有图像按钮btnPlaylist；
私有图像按钮BTN重复；
私人图像按钮btnShuffle；
私人SeekBar Songbar；
私有文本视图歌曲标题标签；
私有文本视图songCurrentDurationLabel；
私有文本视图songTotalDurationLabel；
//媒体播放器
私人媒体播放器；
//用于更新UI计时器、进度条等的处理程序，。
私有处理程序mHandler=新处理程序（）；；
私人歌曲经理；
私人公用事业和公用事业；
private int seekForwardTime=5000；//5000毫秒
private int seekBackwardTime=5000；//5000毫秒
私有int currentSongIndex=0；
私有布尔值isShuffle=false；
私有布尔值isRepeat=false；
private ArrayList songsList=new ArrayList（）；
@凌驾
创建时的公共void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.player）；
//所有播放器按钮
btnPlay=（ImageButton）findViewById（R.id.btnPlay）；
btnForward=（ImageButton）findViewById（R.id.btnForward）；
btnBackward=（ImageButton）findViewById（R.id.btnBackward）；
btnNext=（ImageButton）findViewById（R.id.btnNext）；
btnPrevious=（ImageButton）findViewById（R.id.btnPrevious）；
btnPlaylist=（ImageButton）findViewById（R.id.btnPlaylist）；
btnRepeat=（ImageButton）findViewById（R.id.btnRepeat）；
btnShuffle=（ImageButton）findViewById（R.id.btnShuffle）；
songProgressBar=（SeekBar）findViewById（R.id.songProgressBar）；
songTitleLabel=（TextView）findViewById（R.id.songTitle）；
songCurrentDurationLabel=（TextView）findViewById（R.id.songCurrentDurationLabel）；
songTotalDurationLabel=（TextView）findViewById（R.id.songTotalDurationLabel）；
//媒体播放器
mp=新媒体播放器（）；
songManager=新的SongsManager（）；
utils=新的实用程序（）；
//听众
songProgressBar.setOnSeekBarChangeListener（此）；//重要
mp.setOnCompletionListener（this）；//重要
//获取所有歌曲列表
songsList=songManager.getPlayList（）；
//默认情况下播放第一首歌曲
播放歌曲（0）；
/**
*播放按钮点击事件
*播放歌曲并更改按钮以暂停图像
*暂停歌曲并更改按钮以播放图像
* */
btnPlay.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图arg0）{
//检查是否已播放
if（mp.isPlaying（））{
如果（mp！=null）{
mp.pause（）；
//将按钮图像更改为播放按钮
btnPlay.setImageResource（R.drawable.btn_play）；
}
}否则{
//简历歌
如果（mp！=null）{
mp.start（）；
//将按钮图像更改为暂停按钮
btnPlay.setImageResource（R.drawable.btn\u暂停）；
}
}
}
});
/**
*前进按钮点击事件
*转发指定的歌曲秒数
* */
btnForward.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图arg0）{
//获取当前歌曲位置
int currentPosition=mp.getCurrentPosition（）；
//检查seekForward时间是否小于歌曲持续时间
如果（当前位置+查看前进时间=0）{
//前进歌曲
mp.seekTo（当前位置-seekBackwardTime）；
}否则{
//回到起始位置
希克托议员（0）；
}
}
});
/**
*下一步按钮单击事件
*使用currentSongIndex+1播放下一首歌曲
* */
btnNext.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图arg0）{
//检查是否有下一首歌
如果（当前歌曲索引<（歌曲列表大小（）-1））{
播放歌曲（当前歌曲索引+1）；
currentSongIndex=currentSongIndex+1；
}否则{
//播放第一首歌
播放歌曲（0）；
当前指数=0；
}
}
});
/**
*后退按钮单击事件
*按currentSongIndex播放上一首歌曲-1
* */
btnPrevious.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共空间