I have an bouncing ball game in java,but i need an solution for my question to add in my code:

The player changes the ball rotation direction by pressing the O key.

I upload the source code in google drive:

https://drive.google.com/open?id=1GZw4EE5Sv-2kizYV_0KTVpdbf576hHKi

Please help me with that question.

Thanks