I don't feel like I need to apologize after hitting someone with the door
Why did you hit him?
It was an accident. I wanted to kick him out of my room so I opened the door without looking.
Even if it is not intentional, it is not good to hurt someone and not apologize. They  still feel the pain and deserve to be acknowledge.
I don't think that I should apologize. He should've gotten worse for what he was doing in the first place.
You can still apologize for hitting them with the door, and explain why you were frustrated with them. That way there are no hard feelings between the two of you.