Android查询系统的音频（音乐播放器的核心）

//查询系统的音频库
    public static List<MusicBean> getMusicInfo(Context context){
        List<MusicBean> musicList= new ArrayList<>();
        //查询音频数据库
        Cursor c = context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, MediaStore.Audio.Media.DURATION+">=?", new String[]{"20000"}, MediaStore.Audio.Media.DEFAULT_SORT_ORDER);

        while (c.moveToNext()){
           MusicBean musicBean=new MusicBean();
            musicBean.setTitle(c.getString(c.getColumnIndex(MediaStore.Audio.Media.TITLE)));
            musicBean.setName(c.getString(c.getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME)));
            //对未知艺术家进行判断
            String singer = c.getString(c.getColumnIndex(MediaStore.Audio.Media.ARTIST));
            if(singer==null || "".equals(singer) || "<unknown>".equals(singer)){
                singer = "未知艺术家";
            }
            musicBean.setSinger(singer);
            musicBean.setAlbum(c.getString(c.getColumnIndex(MediaStore.Audio.Media.ALBUM)));
            musicBean.setSize(c.getLong(c.getColumnIndex(MediaStore.Audio.Media.SIZE)));
            musicBean.setTime(c.getLong(c.getColumnIndex(MediaStore.Audio.Media.DURATION)));
            musicBean.setUrl(c.getString(c.getColumnIndex(MediaStore.Audio.Media.DATA)));
            musicList.add(musicBean);

        }
        //关闭游标，释放资源
        c.close();
        return musicList;
    }