java模拟实现spring的AOP

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核心提示：package com.s2sh.intercepetor; public interface IHello { public void sayHello(String name); public void sayGoogBye(String name); } package com.

package com.s2sh.intercepetor;
 
 
 public interface IHello {
     public void sayHello(String name);
     
     public void sayGoogBye(String name);
 }
 
 
 package com.s2sh.intercepetor;
 
 public class Hello implements IHello {
 
 
     public void sayGoogBye(String name) {
         // TODO Auto-generated method stub
         System.out.println(name+" GoodBye!");
     }
 
 
     public void sayHello(String name) {
         // TODO Auto-generated method stub
         System.out.println("Hello " + name);
     }
 
 }
 
 package com.s2sh.intercepetor;
 
 
 public class Logger {
     public static void before() {
         System.out.println("开始了");
     }
     
     public static void after() {
         System.out.println("结束了");
     }
 }
 
 
 
 package com.s2sh.intercepetor;
 
 import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 
 
 public class DynaProxyHello implements InvocationHandler {
     private Object delegate;//被代理的对象
 
     public DynaProxyHello(Object delegate) {
         this.delegate = delegate;
     }
     public Object invoke(Object proxy, Method method, Object[] args)
             throws Throwable {
         // TODO Auto-generated method stub
         Object result = null;
         try {
             // 执行原来的方法之前记录日志
             Logger.before();
             // JVM通过这条语句执行原来的方法(反射机制)
             result = method.invoke(this.delegate, args);
             // 执行原来的方法之后记录日志
             Logger.after();
         } catch (Exception e) {
             e.printStackTrace();
         }
         // 返回方法返回值给调用者
         return result;
     }
 
 
 }
 
 
 package com.s2sh.intercepetor;
 
 import java.lang.reflect.Proxy;
 
 public class Test {
     public static void main(String[] args) {
         // ①目标业务类
         IHello target = new Hello();
         // ② 将目标业务类和横切代码编织到一起
         DynaProxyHello handler = new DynaProxyHello(target);
         // 创建代理类
         IHello proxy = (IHello) Proxy.newProxyInstance(
                                            target.getClass().getClassLoader(), //返回目标类的类装载器，保持两个类的类装载器一样
                                            target.getClass().getInterfaces(), //返回目标类实现的接口，保证组合而成的代理类也实现这些接口
                                            handler//指派谁去处理方法的对象 
                                            );
         // ④ 操作代理实例
         proxy.sayHello("张三");
         proxy.sayGoogBye("李四");
     }
 }