54_55总结分析动态代理类的设计原理与结构

final ArrayList target=new ArrayList();
Collection proxy3 = (Collection) getProxy(target,new MyAdvice());

public static Object getProxy(final Object target,final Advice advice) {
    Object proxy3 = Proxy.newProxyInstance(
            Collection.class.getClassLoader(), 
            new Class[]{Collection.class}, 
            new InvocationHandler(){
                @Override
                public Object invoke(Object proxy, Method method,
                        Object[] args) throws Throwable {
                    advice.beforeMethod(method);
                    Object reVal=method.invoke(target, args);
                    advice.afterMethod(method);
                    return reVal;
                }
            }
        );
    return proxy3;
}

package com.itcast.day3;

import java.lang.reflect.Method;

public interface Advice {
    public void beforeMethod(Method method);
    public void afterMethod(Method method);
}

package com.itcast.day3;

import java.lang.reflect.Method;

public class MyAdvice implements Advice {
    long beginTime=0;
    @Override
    public void beforeMethod(Method method) {
        beginTime=System.currentTimeMillis();
    }

    @Override
    public void afterMethod(Method method) {
        long endTime=System.currentTimeMillis();
        System.out.println(method.getName()+" running "+(endTime-beginTime));
    }
}