code: public void setVideoURI(Uri uri) throws IOException, IllegalStateException, SecurityException, IllegalArgumentException, RuntimeException {
          Log.d(TAG, "setVideoURI");
          if (mediaPlayer != null) {
              if (currentState != State.IDLE)
                  throw new IllegalStateException("FullscreenVideoView Invalid State: " + currentState);
  
              this.videoUri = uri;
              this.videoPath = null;
              this.mediaPlayer.setDataSource(context, uri);
  
              this.currentState = State.INITIALIZED;
              prepare();
          } else throw new RuntimeException("Media Player is not initialized");
      }
docs: VideoView method (setVideoURI)