Solve the problem that android 6.0 or above cannot read external storage permissions

When the local video of mobile phone sdcard is obtained through the content provider,

/**
  *  From local sdcard Get data 
  * //1. Traversal sdcard, Suffix name 
  * //2. Get video from content provider 
  * //3. If it is 6.0 The system of dynamic acquisition and reading sdcard Permissions of 
  */
 private void getDataFromLocal() {

  new Thread(){
   @Override
   public void run() {
    super.run();

//    isGrantExternalRW((Activity) context);
//    SystemClock.sleep(2000);
    mediaItems = new ArrayList<>();
    ContentResolver resolver = context.getContentResolver();
    Uri uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
    String[] objs = {
      MediaStore.Video.Media.DISPLAY_NAME,// Video files are stored in the sdcard Name of 
      MediaStore.Video.Media.DURATION,// Total video duration 
      MediaStore.Video.Media.SIZE,// File size of video 
      MediaStore.Video.Media.DATA,// Absolute address of video 
      MediaStore.Video.Media.ARTIST,// A singer of a song 

    };
    Cursor cursor = resolver.query(uri, objs, null, null, null);
    if(cursor != null){
     while (cursor.moveToNext()){

      MediaItem mediaItem = new MediaItem();

      mediaItems.add(mediaItem);// Write it on it 

      String name = cursor.getString(0);// Name of video 
      mediaItem.setName(name);

      long duration = cursor.getLong(1);// Duration of video 
      mediaItem.setDuration(duration);

      long size = cursor.getLong(2);// File size of video 
      mediaItem.setSize(size);

      String data = cursor.getString(3);// Play address of video 
      mediaItem.setData(data);

      String artist = cursor.getString(4);// Artist 
      mediaItem.setArtist(artist);



     }

     cursor.close();


    }


    //Handler Send a message 
    handler.sendEmptyMessage(10);


   }
  }.start();

 }

 /**
  *  Solve Android 6.0 The above version cannot read the external storage permissions 
  * @param activity
  * @return
  */
 public static boolean isGrantExternalRW(Activity activity) {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && activity.checkSelfPermission(
    Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

   activity.requestPermissions(new String[]{
     Manifest.permission.READ_EXTERNAL_STORAGE,
     Manifest.permission.WRITE_EXTERNAL_STORAGE
   }, 1);

   return false;
  }

  return true;
 }