JAVA中的代理代码示例

import org.springframework.cglib.proxy.Enhancer;
import org.springframework.cglib.proxy.MethodInterceptor;
import org.springframework.cglib.proxy.MethodProxy;

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

public class ProxyTest {
    public static void main(String[] args) {
        //静态代理
        Speaker speakerStaic = new Lawyer(new ZhangSan());
        speakerStaic.speak();

        //JDK动态代理  解决每个类都必须有代理类的问题，依旧需要实现统一的接口  通过反射
        LaywerProxy laywerProxy  = new LaywerProxy(new Lisi());
        Speaker speakerJDK = (Speaker) Proxy.newProxyInstance(ProxyTest.class.getClassLoader(), new Class[]{Speaker.class},laywerProxy);
        speakerJDK.speak();

        //cglib 动态代理  第三方类生成器，不用再实现统一的接口，作为JDK动态代理的补充
        LawyerInteceptor lawyerInteceptor = new LawyerInteceptor(new WangWu());
        WangWu wangWu = (WangWu) Enhancer.create(WangWu.class,lawyerInteceptor);
        wangWu.speak();
        //JDK动态代理和CGLIB字节码生成的区别？
 		//（1）JDK动态代理只能对实现了接口的类生成代理，而不能针对类
 		//（2）CGLIB是针对类实现代理，主要是对指定的类生成一个子类，覆盖其中的方法
   		//因为是继承，所以该类或方法最好不要声明成final 
    }

}


interface Speaker{
    void speak();
}

class Lawyer implements Speaker{
    ZhangSan zhangSan ;
    Lawyer(ZhangSan zhangSan){
        this.zhangSan = zhangSan;
    }
    @Override
    public void speak() {
        System.out.println("引用法律条文");
        zhangSan.speak();
        System.out.println("总结陈述");
    }
}

class ZhangSan implements Speaker{
    @Override
    public void speak(){
        System.out.println("我是张三，我老婆打我");
    }
}


class LaywerProxy implements InvocationHandler{
    Object obj;
    LaywerProxy(Object obj){
        this.obj = obj;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        if(method.getName().equals("speak")){
            System.out.println("引用法律条文");
            method.invoke(obj,args);
            System.out.println("总结陈述");
        }
        return null;
    }
}

class Lisi implements Speaker{
    @Override
    public void speak(){
        System.out.println("我是李四，我老婆打我");
    }
}




class LawyerInteceptor implements MethodInterceptor{

    private Object obj;
    LawyerInteceptor(Object obj){
        this.obj = obj;
    }
    @Override
    public Object intercept(Object o, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        if(method.getName().equals("speak")){
            System.out.println("引用法律条文");
            method.invoke(obj,args);
            System.out.println("总结陈述");
        }
        return null;
    }
}

class WangWu implements Speaker{
    @Override
    public void speak(){
        System.out.println("我是王五，我老婆打我");
    }
}