Character sprite rotation

So I’m new to coding in Java.

I’m making an endless runner, so the character never stops, only jumps. I have 8 sprites for running animation, and one for jumping.
Currently I’ve been using just a single image with a simple line of code assinging a .png to a BufferedImage, and then return it to my level class, where I use Graphics2D to draw it. I haven’t gotten to jumping part yet but the idea was something in the lines of checking if the character is jumping and if he is not then the rotation presumes.

How should I go about to make the sprites rotate? I tried a couple of simple ways, like doing a for loop with thread sleep but the image didn’t update.