Spring中AOP：Proxy动态代理浅解析（被代理对象必须实现接口）

Posted 2020-11-10 呦，你是个老母猪呦！

小贴士：以下内容纯属个人观点，如有不当请指出并谅解

import java.lang.reflect.Proxy;

Proxy可以动态代理一个对象

写一个代理工厂类ProxyFactory：

package com.zhangpn.serviceImpl;

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

public class ProxyFactory implements InvocationHandler {
    private Object target;//这是被动态代理的对象
    
    public Object createProxyIntance(Object target) {//通过调用此方法,将被代理目标传入并且返回代理对象,在此invoke方法会被回调
        this.target = target;
        return Proxy.newProxyInstance(this.target.getClass().getClassLoader(), this.target.getClass().getInterfaces(), this);
    }
    
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("******调用动态被代理对象之前做相关处理******");
        method.invoke(target, args);
        System.out.println("------调用动态被代理对象之后做相关处理------\\n");
        return null;
    }

}

写两个被代理类：

第一个User：

package com.zhangpn.daoImpl;

import com.zhangpn.dao.UserDao;

public class UserDaoImpl implements UserDao {
	
	public void save() {
		System.out.println("UserDaoImpl save success!");
	}

}

其实现的接口：

package com.zhangpn.dao;

public interface UserDao {
	public void save();
}

第二个Student：

package com.zhangpn.daoImpl;

import com.zhangpn.dao.StudentDao;

public class StudentDaoImpl implements StudentDao {
	
	public void save() {
		System.out.println("StrudentDaoImpl save success!");
	}

}

其实现的接口：

package com.zhangpn.dao;

public interface StudentDao {
	public void save();
}

　　测试运行：

package com.zhangpn.Test;

import com.zhangpn.dao.StudentDao;
import com.zhangpn.dao.UserDao;
import com.zhangpn.daoImpl.StudentDaoImpl;
import com.zhangpn.daoImpl.UserDaoImpl;
import com.zhangpn.serviceImpl.ProxyFactory;

public class Test {

	public static void main(String[] args) {
		ProxyFactory factory = new ProxyFactory();
		UserDao userDao = (UserDao) factory.createProxyIntance(new UserDaoImpl());
		userDao.save();
		StudentDao studentDao = (StudentDao) factory.createProxyIntance(new StudentDaoImpl());
		studentDao.save();
	}

}

　　

---