JAVA课程设计(打砖块)

import java.awt.*; import javax.swing.*; import java.awt.event.*; import javax.swing.event.*; public class HitBrick extends JFrame implements KeyListener{ private BallThread greenBallThread;//控制小球的线程 private boolean xUp,yUp,bouncing; private int x,y,xDx,yDy;//小球坐标,增量 private final int MAX_