Problems using collisions

For some collision aren’t working in my game. I’ve tried other ways and still could not get it to work. The player is suppose to stay on the floor and when a peice of the floor is gone the player can fall through it.

Main
http://pastebin.java-gaming.org/0c47d43634619
Game Screen
http://pastebin.java-gaming.org/f0c473d634316
Images