One way would be to keep track yourself of what keys are currently down.
When you get a keyPressed event, add the new key to the list; when you get a keyReleased event, remove the key from the list.
Then in your game loop, you can do actions based on what's in the list of keys.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…