注解实现AOP

AnnotationPointCut.java

package com.kuang.diy;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

/**
 * @author Administrator
 * 使用注解方式实现AOP
 * Aspect 标注这个类是切面
 */
@Aspect
public class AnnotationPointCut {

    @Before("execution(* com.kuang.service.UserServiceImpl.*(..))")
    public void before(){
        System.out.println(">>>>>方法执行前<<<<<<");
    }

    @After("execution(* com.kuang.service.UserServiceImpl.*(..))")
    public void after(){
        System.out.println(">>>>>方法执行后<<<<<<");
    }

    /**
     * 在环绕增强中,我们可以给定一个参数,代表我们要获取处理切入的点
     * 执行顺序:环绕前 => 方法执行前 => 环绕后 => 方法执行后
     */
    @Around("execution(* com.kuang.service.UserServiceImpl.*(..))")
    public void around(ProceedingJoinPoint jp) throws Throwable {
        System.out.println(">>>>>环绕前<<<<<<");

        //获得签名
        Signature signature = jp.getSignature();
        System.out.println("signature:" + signature);

        //执行方法
        Object proceed = jp.proceed();

        System.out.println(">>>>>环绕后<<<<<<");
        System.out.println(proceed);
    }

}

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd">
    
    <!--方式三、注解实现-->
    <bean id="annotationPointCut" class="com.kuang.diy.AnnotationPointCut"/>
    <!--开启注解支持-->
    <aop:aspectj-autoproxy/>

</beans>

测试类

import com.kuang.service.UserService;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MyTest {
    public static void main(String[] args) {

        ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
        /**
         * 动态代理，代理的是接口
         */
        UserService userService = context.getBean("userService", UserService.class);

        userService.add();

    }
}

结果

>>>>>环绕前<<<<<<
signature:void com.kuang.service.UserServiceImpl.add()
>>>>>方法执行前<<<<<<
增加了一个用户
>>>>>环绕后<<<<<<
null
>>>>>方法执行后<<<<<<