//扫描本地音乐
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
  new Thread()
  {
    @Override
    public void run()
    {
      try
      {
      String[] ext = { ".mp3" };
      File file = new File(Environment.getExternalStorageDirectory()+"/Android/data/com.tencent.qqmusic/files/qqmusic/song");//可以把"//////"这一串都去掉，扫面范围是整个SD卡，我嫌慢，而且扫出来很多...不是我想要的歌曲，最后还是直接写成QQ音乐的下载目录了，其实自己的APP支持下载的话，可以把歌曲下载的指定目录，然后扫描这个指定目录就行了~全局扫描的确不太合适，又不是杀毒..
      localMusicList = Common.searchMp3Infos(file,ext);
      hander.sendEmptyMessage(SEARCH_MUSIC_SUCCESS);
      }catch (Exception e){}
      }
    }.start();
}

//扫描实现
  static List<String> list = new ArrayList<>();
  public static List<String> searchMp3Infos(File file, String[] ext) {
    if (file != null) {
      if (file.isDirectory()) {
        File[] listFile = file.listFiles();
        if (listFile != null) {
          for (int i = 0; i < listFile.length; i++) {
            searchMp3Infos(listFile[i], ext);
          }
        }
      } else {
        String filename = file.getAbsolutePath();
        for (int i = 0; i < ext.length; i++) {
          if (filename.endsWith(ext[i])) {
            list.add(filename);
            break;
          }
        }
      }
    }
    return list;
  }

public static List<HashMap<String, Object>> getMp3Infos(Context context)
  {
    Cursor cursor = context.getContentResolver().query(
        MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null,
        null, null, null);
    ArrayList mp3Infos = new ArrayList();
    for (int i = 0; i < cursor.getCount(); i++) {
      cursor.moveToNext();
      HashMap<String, Object> musicMap = new HashMap<>();
      long id = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media._ID));//音乐id
      String title = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));//音乐标题
      String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));//艺术家
      String album = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));//专辑
      long albumid = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));//专辑id
      long duration = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));//时长
      long size = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.SIZE));//文件大小
      String url = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));//文件路径
      int isMusic = cursor.getInt(cursor.getColumnIndex(MediaStore.Audio.Media.IS_MUSIC));//是否为音乐
      if (isMusic != 0) {
        musicMap.put("id",id);
        musicMap.put("title",title);
        musicMap.put("artist",artist);
        musicMap.put("album",album);
        musicMap.put("albumid",albumid);
        musicMap.put("duration",duration);
        musicMap.put("size",size);
        musicMap.put("url",url);
        musicMap.put("isMusic",isMusic);
        mp3Infos.add(musicMap);
      }
    }
    cursor.close();
    return mp3Infos;
  }