java动态代理的实现

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">java动态代理的实现：</span>

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">
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package com.test.interf;

public interface UserDao {

public int add(int x,int y);

}

package com.test.impli;

import com.test.interf.UserDao;

public class UserDaoImpl implements UserDao {

@Override
public int add(int x, int y) {

int sum = x + y;

return sum;

}

}

package com.test.proxy;

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

import com.test.interf.UserDao;

public class UserProxy {

private UserDao target;

public UserProxy(UserDao target) {
super();
this.target = target;
}

public UserDao getUserProxy() {

UserDao proxy = null;

ClassLoader loader = target.getClass().getClassLoader();

Class[] interfaces = new Class[]{UserDao.class};

InvocationHandler h = new InvocationHandler() {

@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
String methodName = method.getName();
System.out.println("start \\\\ methodName is:::::"+methodName + " args is::"+Arrays.toString(args));

Object result = null;

result = method.invoke(target, args);

System.out.println("end \\\\");

return result;
}
};

proxy = (UserDao) Proxy.newProxyInstance(loader, interfaces, h);

return proxy;
}

}

package com.test.test;

import com.test.impli.UserDaoImpl;
import com.test.interf.UserDao;
import com.test.proxy.UserProxy;

public class Main {

public static void main(String[] args) {

UserDao ud = new UserDaoImpl();

ud = new UserProxy(ud).getUserProxy();

ud.add(1, 2);

}

}