Cglib动态代理

矫情吗；* 2022-06-06 03:41 293阅读 0赞

package cn.itcast.proxy.cglib;
    
    //只有实现类,没有接口
    public class UserDaoImpl {
    
        public void save(){
            System.out.println("保存用户");
        }
    }

package cn.itcast.proxy.cglib;
    
    import java.lang.reflect.Method;
    
    import org.springframework.cglib.proxy.Enhancer;
    import org.springframework.cglib.proxy.MethodInterceptor;
    import org.springframework.cglib.proxy.MethodProxy;
    
    //使用Cglib实现动态代理,适合目标类没有实现接口,代理类是目标类的子类,生成的代理对象是目标类子类的对象
    //使用Cglib必须要导入cglib包,Spring中已集成
    public class UserDaoImplProxyUtils {
    
        public static UserDaoImpl getProxy(){
            //Ehancer是Cglib的核心类
            Enhancer enhancer = new Enhancer();
    
            //要代理哪个目标类
            enhancer.setSuperclass(UserDaoImpl.class);
    
            //设置回调函数,代理对象的方法一执行,就会调用回调函数
            enhancer.setCallback(new MethodInterceptor() {
    
                @Override
                public Object intercept(Object obj, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
                    if("save".equals(method.getName())){
                        System.out.println("开启事务");
                    }
                    Object invoke = methodProxy.invokeSuper(obj, args);
                    if("save".equals(method.getName())){
                        System.out.println("关闭事务");
                    }
                    return invoke;
                }
            });
    
            //返回代理对象
            UserDaoImpl proxy = (UserDaoImpl) enhancer.create();
            return proxy;
        }
    }

package cn.itcast.proxy.cglib;
    
    public class UserDaoImplProxyTest {
    
        public static void main(String[] args) {
            UserDaoImpl user = new UserDaoImpl();
            user.save();
    
            System.out.println("...................");
    
            UserDaoImpl proxy = UserDaoImplProxyUtils.getProxy();
            proxy.save();
        }
    
    }

![这里写图片描述][SouthEast]

[SouthEast]: /images/20220606/90daf631f160423fa833ef2097f1bd1d.png