Cglib动态代理

<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>3.2.5</version>
</dependency>

public class UserDao{

    public void save() {
        System.out.println("保存数据");
    }
}

package com.cglib;

import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class ProxyFactory implements MethodInterceptor{

    private Object target;//维护一个目标对象
    public ProxyFactory(Object target) {
        this.target = target;
    }
    
    //为目标对象生成代理对象
    public Object getProxyInstance() {
        //工具类
        Enhancer en = new Enhancer();
        //设置父类
        en.setSuperclass(target.getClass());
        //设置回调函数
        en.setCallback(this);
        //创建子类对象代理
        return en.create();
    }

    @Override
    public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
        System.out.println("开启事务");
        // 执行目标对象的方法
        Object returnValue = method.invoke(target, args);
        System.out.println("关闭事务");
        return null;
    }
}

package com.cglib;

import org.junit.Test;

public class TestProxy {

    @Test
    public void testCglibProxy(){
        //目标对象
        UserDao target = new UserDao();
        System.out.println(target.getClass());
        //代理对象
        UserDao proxy = (UserDao) new ProxyFactory(target).getProxyInstance();
        System.out.println(proxy.getClass());
        //执行代理对象方法
        proxy.save();
    }
}

结果

class com.cglib.UserDao
class com.cglib.UserDao$$EnhancerByCGLIB$$552188b6
开启事务
保存数据
关闭事务