使用MeidaStore.Audio获得手机中的音频文件

public class Music {
    private String filename;
    private String title;
    private int during;
    private String singer;
    private String type;
    private String size;
    private String fileUrl;
    public Music(String filename,String title,int during,String singer,String type,String size,String fileUrl){
        this.filename = filename;
        this.title = title;
        this.during = during;
        this.singer = singer;
        this.type = type;
        this.size = size;
        this.fileUrl = fileUrl;
    }
    public String toString(){
        return "song[filename="+filename+", title="+title+", during="+during+", singer="+singer+", type="+type+", size="+size+", fileUrl="+fileUrl+"]";
    }
    public String getFilename() {
        return filename;
    }
    public void setFilename(String filename) {
        this.filename = filename;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public int getDuring() {
        return during;
    }
    public void setDuring(int during) {
        this.during = during;
    }
    public String getSinger() {
        return singer;
    }
    public void setSinger(String singer) {
        this.singer = singer;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getSize() {
        return size;
    }
    public void setSize(String size) {
        this.size = size;
    }
    public String getFileUrl() {
        return fileUrl;
    }
    public void setFileUrl(String fileUrl) {
        this.fileUrl = fileUrl;
    }
    
}

public class MusicHelper{
    public static List<Music> songs = new ArrayList<Music>();
    public static List<Music> getAllsongs(Context context){
            Cursor cursor1 = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,null,null,null,null);
            getcorrSongs(cursor1);
            Cursor cursor2 = context.getContentResolver().query(MediaStore.Audio.Media.INTERNAL_CONTENT_URI,null,null,null,null);
            getcorrSongs(cursor2);
        return songs;
    }
    public static void getcorrSongs(Cursor cursor){
        Music song = null;
        if(cursor != null){
            while(cursor.moveToNext()){
                String filename = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME));
                String title = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.TITLE));
                int during = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));
                String singer = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST));
                String type = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.MIME_TYPE));
                String size = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE));
                String date = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));
                song = new Music(filename,title,during,singer,type,size,date);
                songs.add(song);
            }    
            cursor.close();
        }
    }
}

allsongs = MusicHelper.getAllsongs(this);