JDK的動態代理是基於介面的

 package  com.open.aop;
 public   interface  BusinessInterface  {
     public   void  processBusiness();
}

package com.open.aop;
public class BusinessObject implements BusinessInterface {
    public void processBusiness() {
        System.out.println("action");
    }
}

package com.open.aop;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
public class LogHandler implements InvocationHandler {
    private Object delegate;
    public Object binder(Object delegate) {
        this.delegate=delegate;
        return Proxy.newProxyInstance(delegate.getClass().getClassLoader(),
                delegate.getClass().getInterfaces(),this);
    }
    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        Object obj = null;
        System.out.println("物件方法呼叫前");
        try {
            obj = method.invoke(delegate, args);
        } catch (Exception e) {
        }
        System.out.println("物件方法呼叫後"); 
        return obj;
    }
}
 

package com.open.aop;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
public class Test {
    public static void main(String[] args) {
        BusinessInterface bi = (BusinessInterface) new LogHandler()
                .binder(new BusinessObject());
        bi.processBusiness();
    }
}