设计模式之代理模式 Proxy

public interface Star {

    /**
     * 面谈
     */
    void confer();
    /**
     * 签合同
     */
    void signContract();
    /**
     * 订票
     */
    void bookTicket();
    /**
     * 唱歌
     */
    void sing();
    /**
     * 收钱
     */
    void collectMoney();
    
}

public class RealStar implements Star{
    

    @Override
    public void confer() {
        System.out.println("真实角色面谈");
    }

    @Override
    public void signContract() {
        System.out.println("真实角色签合同");
    }

    @Override
    public void bookTicket() {
        System.out.println("真实角色订票");
    }

    @Override
    public void sing() {
        System.out.println("真实角色唱歌");
    }

    @Override
    public void collectMoney() {
        System.out.println("真实角色收钱");
    }

}

public class ProxyStar implements Star{

    private Star star;
        
    public ProxyStar(Star star) {
        super();
        this.star = star;
    }

    @Override
    public void confer() {
        System.out.println("代理角色面谈");
    }

    @Override
    public void signContract() {
        System.out.println("代理角色签合同");
    }

    @Override
    public void bookTicket() {
        System.out.println("代理角色订票");
    }

    @Override
    public void sing() {
        star.sing(); //代理角色不能唱歌
    }

    @Override
    public void collectMoney() {
        System.out.println("代理角色收钱");
    }

}

public class Client {

    public static void main(String[] args) {
        Star real = new RealStar();
        Star proxy = new ProxyStar(real);
        
        proxy.confer();
        proxy.signContract();
        proxy.bookTicket();
        proxy.sing();
        
        proxy.collectMoney();
    }
}

public interface Star {

    /**
     * 面谈
     */
    void confer();
    /**
     * 签合同
     */
    void signContract();
    /**
     * 订票
     */
    void bookTicket();
    /**
     * 唱歌
     */
    void sing();
    /**
     * 收钱
     */
    void collectMoney();
    
}

public class RealStar implements Star{
    

    @Override
    public void confer() {
        System.out.println("真实角色面谈");
    }

    @Override
    public void signContract() {
        System.out.println("真实角色签合同");
    }

    @Override
    public void bookTicket() {
        System.out.println("真实角色订票");
    }

    @Override
    public void sing() {
        System.out.println("真实角色唱歌");
    }

    @Override
    public void collectMoney() {
        System.out.println("真实角色收钱");
    }

}

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

public class StarHandler implements InvocationHandler{

    Star realStar;
    
    public StarHandler(Star realStar) {
        super();
        this.realStar = realStar;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        //System.out.println("****查看调用过程*****"); //Client调用的时候经过这里
        
        Object object = null;
        
        System.out.println("真正的方法执行前，面谈，签合同，订票");
        if(method.getName().equals("sing")){
            object = method.invoke(realStar, args);
        }
        System.out.println("真正的方法执行后，收钱");
        return object;
    }

}

public class Client {

    public static void main(String[] args) {
        Star realStar = new RealStar();
        StarHandler handler = new StarHandler(realStar);
        
        Star proxy = (Star) Proxy.newProxyInstance(ClassLoader.getSystemClassLoader(), new Class[]{Star.class}, handler);
        
        proxy.bookTicket();
        proxy.sing();

    }

}