package com.design.proxy;

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

public class ProxySourceTest {
    public static void main(String[] args) throws SecurityException,
            NoSuchMethodException, Throwable {
        ProxyTestInterface p = (ProxyTestInterface) MyInvocationHandler
                .newProxy(new ProxyTestImpl());
        /*
         * byte[] b =
         * ProxyGenerator.generateProxyClass("ProxyTestInterfaceProxy", new
         * Class[] { p.getClass() });
         * 
         * File file=newFile(
         * "D:\\workspace8.5\\MTSJMS\\bin\\com\\design\\proxy\\ProxyTestInterfaceProxy.class"
         * );
         * 
         * FileOutputStream fos=new FileOutputStream(file); fos.write(b);
         * fos.close();
         */
        System.out.println(p.hello("123"));
    }
}

class MyInvocationHandler implements InvocationHandler {
    private Object object;

    public MyInvocationHandler(Object object) {
        this.object = object;
    }

    public static Object newProxy(Object object) {
        return Proxy.newProxyInstance(object.getClass().getClassLoader(),
                object.getClass().getInterfaces(), new MyInvocationHandler(
                        object));
    }

    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
    
        System.out.println(method.invoke(object, args));

        return "error";
    }
}

------解决方案--------------------
spring aop使用了代理模式，当目标对象是接口时作用JDK动态代理，普通类时则使用CGLIB代理
下面是JDK动态代理一个示例

public interface UserDao {
	/**
	 * 切入点
	 */
	public void update();

	public void delete();
}


public class UserDaoImpl implements UserDao {

	public void delete(){
		System.out.println("UserDao delete函数");
	}

	public void update(){
		System.out.println("UserDao update函数");
		
	}

}

public class UserInvocationHandler implements InvocationHandler {
	private Object invocationObj;

	public UserInvocationHandler(Object invocationObj) {
		this.invocationObj = invocationObj;
	}

	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		// TODO Auto-generated method stub
		System.out.println("走JDK动态代理调用函数");// 此方法为:通知
		Object obj = method.invoke(invocationObj, args);
		return obj;
	}

}

/**
  * JDK 动态代理
  *  
  */
public class App {
	@Test
	/**
	 * Aspect-Oriented Programming
	 */
	public void jdkProxy() {
		UserDao dao = new UserDaoImpl();// dao为:目标对象
		Object obj = Proxy.newProxyInstance(dao.getClass().getClassLoader(),
				dao.getClass().getInterfaces(), new UserInvocationHandler(dao));
		UserDao userdao = (UserDao) obj;
		// 以下两个方法为:连接点
		userdao.delete();
		userdao.update();
	}
}

------解决方案--------------------
一般永不到的 只是让你更了解spring 的 AOP