JDK动态代理

UserDao接口

package com.student.jdk;

public interface UserDao {
	public void addUser();
	public void deleteUser();

}

UserDaoImpl实现接口：

package com.student.jdk;
//作为实体类
public class UserDaoImpl implements UserDao {

	@Override
	public void addUser() {
		System.out.println("添加用户！！");
	}

	@Override
	public void deleteUser() {
		System.out.println("删除用户！！");

	}

}

MyAspect ：切面类

package com.student.aspect;
//作为切面类
public class MyAspect {
	public void check_Permissions() {
		System.out.println("模拟检查权限！！！");
	}
	public void log() {
		System.out.println("模拟记录日志！！！");
	}

}

JDkProxy：代理类

package com.student.jdk;

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

import com.student.aspect.MyAspect;

public class JDKProxy implements InvocationHandler {
	private UserDao userDao;
	public Object createProxy(UserDao userDao) {
		this.userDao = userDao;
		ClassLoader classLoader = JDKProxy.class.getClassLoader();
		Class[] clazz = userDao.getClass().getInterfaces();
		return Proxy.newProxyInstance(classLoader,clazz,this);
	}

	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
		MyAspect myAspect =new MyAspect();
		myAspect.check_Permissions();
		Object obj = method.invoke(userDao, args);
		myAspect.log();
		return obj;
	}

}

JDKTest：测试类

package com.student.jdk;

public class JdkTest {

	public static void main(String[] args) {
		JDKProxy jdkProxy = new JDKProxy();
		UserDao userDao = new UserDaoImpl();
		UserDao userDao1 = (UserDao)jdkProxy.createProxy(userDao);
		userDao1.addUser();
		userDao1.deleteUser();
	}
}

运行结果：

模拟检查权限！！！
添加用户！！
模拟记录日志！！！
模拟检查权限！！！
删除用户！！
模拟记录日志！！！