观察者模式

public class Car {
	private String name ;
	private int x ;
	private int y ;
	
	private HashSet<CarListener> listeners = new HashSet<CarListener>();
	
	
	public Car(String name, int x, int y) {
		super();
		this.name = name;
		this.x = x;
		this.y = y;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getX() {
		return x;
	}

	public void setX(int x) {
		this.x = x;
	}

	public int getY() {
		return y;
	}

	public void setY(int y) {
		this.y = y;
	}

	public void drawMe(Graphics g){
		g.drawRect(x, y, 50, 50);
	}
	
	
	
	public void driver(){
		for(CarListener l:listeners){
			l.move(this);
		}
		System.out.println("开始驾驶");
	}
	
	public void stop(){
		for(CarListener l:listeners){
			l.move(this);
		}
		System.out.println("停车");
	}
	
	public void addListener(CarListener l){
		this.listeners.add(l);
	}
	
	
}

　　

public interface CarListener {
		
	public void move(Car car);
}

　　

public class Controller extends KeyAdapter implements CarListener{

	private Car car ;
	
	@Override
	public void keyPressed(KeyEvent e) {
		super.keyPressed(e);
		System.out.println("处理按键事件");
		int x = car.getX();
		int y = car.getY();
		switch (e.getKeyCode()) {
		case KeyEvent.VK_W:
			y-=10;
			car.setY(y);
			move(car);
			break;
		case KeyEvent.VK_S:
			y+=10;
			car.setY(y);
			move(car);
			break;


		default:
			break;
		}
		
		
	}
	
	public Controller(Car car) {
		super();
		this.car = car;
	}


	@Override
	public void move(Car car) {
		System.out.println("control move方法"+car);
		System.out.println("控制器的move方法");
	}

}

　　

public class GameFrame extends JFrame implements Runnable{
	private Car car ;

	public GameFrame(Car c){
		this.car = c ;
		this.setLocation(400, 50);
		this.setSize(500, 500);
		this.setDefaultCloseOperation(3);
		this.setVisible(true);
	}
	
	@Override
	public void paint(Graphics g) {
		super.paint(g);
		car.drawMe(g);
	}

	@Override
	public void run() {
		while(true){
			try {
				Thread.sleep(500);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			int x = car.getX();
			car.setX(++x);
			repaint();
		}
		
	}
	
	
}