public void getAlldata() {
        ContentResolver cr = getApplication().getContentResolver();
        if (cr == null) {
            return;
        }
        // 获取所有歌曲
        Cursor cursor = cr.query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                null, null, null, MediaStore.Audio.Media.DEFAULT_SORT_ORDER);
        if (null == cursor) {
            return;
        }
        Music music;
        List<Music> list = new ArrayList<MainActivity.Music>();
        if (cursor.moveToFirst()) {
            do {

                //歌曲名
                String title = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.TITLE));

                //歌手
                String singer = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ARTIST));

                //专辑
                String album = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ALBUM));

                //长度
                long size = cursor.getLong(cursor
                        .getColumnIndex(MediaStore.Audio.Media.SIZE));

                //时长
                int duration = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media.DURATION));

                //路径
                String url = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.DATA));

                //显示的文件名
                String _display_name = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));

                //类型
                String mime_type = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.MIME_TYPE));
                music = new Music();
                music.setAlbum(album);
                music.setDuration(duration);
                music.setSinger(singer);
                music.setSize(size);
                music.setTitle(title);
                music.setUrl(url);
                music.set_display_name(_display_name);
                music.setMime_type(mime_type);
                list.add(music);
            } while (cursor.moveToNext());
        }
        System.out.println(list.size());
    }
    class Music
    {
        private  String title;
        private  String singer;
        private  String album;
        private  long size;
        private  int duration;
        private  String url;
        private  String _display_name;
        private String mime_type;

        public String get_display_name() {
            return _display_name;
        }
        public void set_display_name(String _display_name) {
            this._display_name = _display_name;
        }
        public String getMime_type() {
            return mime_type;
        }
        public void setMime_type(String mime_type) {
            this.mime_type = mime_type;
        }
        public String getTitle() {
            return title;
        }
        public void setTitle(String title) {
            this.title = title;
        }
        public String getSinger() {
            return singer;
        }
        public void setSinger(String singer) {
            this.singer = singer;
        }
        public String getAlbum() {
            return album;
        }
        public void setAlbum(String album) {
            this.album = album;
        }
        public long getSize() {
            return size;
        }
        public void setSize(long size) {
            this.size = size;
        }
        public int getDuration() {
            return duration;
        }
        public void setDuration(int duration) {
            this.duration = duration;
        }
        public String getUrl() {
            return url;
        }
        public void setUrl(String url) {
            this.url = url;
        }
        @Override
        public String toString() {
            return "Music [title=" + title + ", singer=" + singer + ", album="
                    + album + ", size=" + size + ", duration=" + duration
                    + ", url=" + url + ", _display_name=" + _display_name
                    + ", mime_type=" + mime_type + "]";
        }

    }