鲨鱼攻击猎物游戏 是一个Applet程序

				package shark;
				
				import java.awt.*;
				
				/**
				 * 猎物类，实现猎物的显示、移动、以及判断是否被鲨鱼吃掉等功能
				 */
				public class SharkPrey {
				    private SharkAttack applet = null;
				
				    private Image animal = null; //猎物的图片
				
				    private Rectangle bounds = new Rectangle();
				
				    private int deltaX, amp; //位移和振幅
				
				    public SharkPrey(Image _animal, SharkAttack _applet) {
				        animal = _animal;
				        applet = _applet;
				        deltaX = (int) (2 * Math.random()) + 1;
				        amp = (int) (55 * Math.random()) + 10;
				        bounds.x = (int) (applet.getSize().width * Math.random());
				        bounds.y = 120 + (int) (amp * Math.sin(bounds.x / 20.0));
				        bounds.height = animal.getHeight(null);
				        bounds.width = animal.getWidth(null);
				    }
				
				    /**
				     * 猎物的移动路线是简单的正弦曲线(振幅是随机的)，初始位置随机产生。
				     */
				    public void move() {
				        if ((bounds.x > applet.getSize().width) || (bounds.x < 0)) {
				            deltaX *= (-1);
				        }
				        bounds.x += deltaX;
				        bounds.y = 120 + (int) (amp * Math.sin(bounds.x / 20.0));
				    }
				
				    /**
				     * @param shark
				     * @return 如果获得的鲨鱼鱼鳍顶点坐标值在猎物所在的矩形区域内，则猎物被吃掉，返回值为true，否则为false
				     */
				    public boolean isEatenBy(Shark shark) {
				        return bounds.contains(shark.getTip());
				    }
				
				    public void paintComponent(Graphics g) {
				        g.drawImage(animal, bounds.x, bounds.y, null);
				    }
				}