代理模式

public interface House {
    void buyHosue();
}

public class BuyHouse implements House {

    @Override
    public void buyHosue() {
        System.out.println("我要买房");
    }
}

public class BuyHouseProxy implements House {

    private House house;

    public BuyHouseProxy(final House house) {
        this.house = house;
    }

    @Override
    public void buyHosue() {
        System.out.println("买房前准备");
        house.buyHosue();
        System.out.println("买房后装修");

    }
}

public class ProxyTest {
    public static void main(String[] args) {
        House house = new BuyHouse();
        house.buyHosue();
        
        BuyHouseProxy buyHouseProxy = new BuyHouseProxy(house);
        buyHouseProxy.buyHosue();
    }
}

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

public class DynamicProxyHandler implements InvocationHandler {

    private Object object;

    public DynamicProxyHandler(final Object object) {
        this.object = object;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("买房前准备");
        Object result = method.invoke(object, args);
        System.out.println("买房后装修");
        return result;
    }
}

import java.lang.reflect.Proxy;

public class DynamicProxyTest {
    public static void main(String[] args) {
        House house = new BuyHouse();
        House proxyBuyHouse = (House) Proxy.newProxyInstance(House.class.getClassLoader(), new
                Class[]{House.class}, new DynamicProxyHandler(house));
        proxyBuyHouse.buyHosue();
    }
}