Android development: how to play mp4 files under assets

1.

public class CustomVideoView extends VideoView {
    public CustomVideoView(Context context){
        super(context);
    }
    public CustomVideoView(Context context, AttributeSet attributeSet){
        super(context,attributeSet);
    }
    public CustomVideoView(Context context,AttributeSet attributeSet,int defStyle){
        super(context,attributeSet,defStyle);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width=getDefaultSize(0,widthMeasureSpec);
        int height=getDefaultSize(0,heightMeasureSpec);
        setMeasuredDimension(width,height);
    }

2.

<com.for3ms.et.widget.CustomVideoView
    android:id="@+id/videoView"
    android:layout_width="match_parent"
    android:layout_height="200dp" />

3.

 4.

String file_path=mActivity.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS).toString()+"/video"; 
//Use VideoView to play video 
VideoView videoView = mBind.videoView; 
String path=file_path+"/dota_montage_02.mp4"; 
Log.d(" Play address", path); 
videoView.setVideoPath(path); 
// Create MediaController object 
MediaController mediaController = new MediaController(mActivity); 
// Bind mediaController 
videoView.setMediaController(mediaController); 
videoView.requestFocus(); 
videoView.start( ); 
mBind.videoView.setOnCompletionListener(new MediaPlayer.OnCompletionListener() { 
    @Override 
    public void onCompletion(MediaPlayer mp) { 
        mBind.videoView.start();  
    }
});

ending~