?概念解釋：（理解基本概念方可快速入手）

1. 連接點(diǎn)（joinpoint）

   被攔截到的點(diǎn)，因?yàn)镾pring只支持方法類型的連接點(diǎn)，所以在Spring中連接點(diǎn)指的就是被攔截到的方法。

2. 切入點(diǎn)（pointcut）

   切入點(diǎn)是指我們要對哪些連接點(diǎn)進(jìn)行攔截的定義

3. 通知（advice）

   所謂通知指的就是指攔截到連接點(diǎn)之后要執(zhí)行的代碼，通知分為前置、后置、異常、最終、環(huán)繞通知五類

4. 切面（aspect）

   是切入點(diǎn)和通知的結(jié)合

?通知順序：

前置通知：aop:before
??????????? 后置通知：aop:after-returning【try】
??????????? 最終通知：aop:after【finally】
??????????? 異常通知：aop:after-throwing【catch】
??????????? 環(huán)繞通知：aop:around

??????????? try{
??????????????? ...
??????????????? return aop:after-returning
??????????? }catch(Exception e){
??????????????? ...
??????????????? aop:after-throwing
??????????? }finally{
??????????????? ...
??????????????? aop:after
??????????? }

切點(diǎn)表達(dá)式：
??????? 格式：execution([修飾符] 返回值 報名.類名.方法名(參數(shù)))
??????? eg：execution(* com.by.service.*.*(..))

?實(shí)例演示：

pom.xml:

<dependencies><!--ioc--><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>6.0.12</version></dependency><!--支持切點(diǎn)表達(dá)式AOP --><dependency><groupId>org.springframework</groupId><artifactId>spring-aspects</artifactId><version>5.1.8.RELEASE</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.7.19</version></dependency></dependencies>

UserDaoImpl:

package com.by.dao;public class UserDaoImpl implements UserDao {@Overridepublic void addUser(){System.out.println("insert into tb_user......");}
}

UserServiceImpl:

package com.by.service;import com.by.dao.UserDao;public class UserServiceImpl implements UserService {private UserDao userDao;public void setUserDao(UserDao userDao) {this.userDao = userDao;}@Overridepublic void addUser(){userDao.addUser();System.out.println(8/0);}
}

MyLogActive:(增強(qiáng)類)

/** Copyright (c) 2020, 2024,  All rights reserved.**/
package com.by.advice;import org.aspectj.lang.ProceedingJoinPoint;/*** <p>Project: Spring - MyLogAdvice</p>* <p>Powered by scl On 2024-01-05 15:04:11</p>* <p>描述：<p>** @author 孫臣龍 [1846080280@qq.com]* @version 1.0* @since 17*/
public class MyLogAdvice {public void after() {System.out.println("最終通知、、、");}public void before() {System.out.println("前置通知、。、");}public void afterReturn(){System.out.println("后置通知");}public void afterThrowing(){System.out.println("異常通知");}public void around(ProceedingJoinPoint joinPoint) {try {System.out.println("前環(huán)繞通知。。。");joinPoint.proceed();System.out.println("后環(huán)繞通知。。。");} catch (Throwable e) {throw new RuntimeException(e);}}
}

?applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!--注意：添加約束-->
<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/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/aophttp://www.springframework.org/schema/aop/spring-aop.xsd"><bean id="userDao" class="com.by.dao.UserDaoImpl"></bean><bean id="userService" class="com.by.service.UserServiceImpl"><property name="userDao" ref="userDao"></property></bean><!--增強(qiáng)--><bean id="myLogAdvice" class="com.by.advice.MyLogAdvice"></bean><!--aop--><aop:config><!--切點(diǎn)--><aop:pointcut id="pointcut" expression="execution(* com.by.service.*.*(..))"/><!--切面--><aop:aspect ref="myLogAdvice"><aop:before method="before" pointcut-ref="pointcut"></aop:before><aop:after method="after" pointcut-ref="pointcut"></aop:after><aop:around method="around" pointcut-ref="pointcut"></aop:around><aop:after-returning method="afterReturn" pointcut-ref="pointcut"></aop:after-returning><aop:after-throwing method="afterThrowing" pointcut-ref="pointcut"></aop:after-throwing></aop:aspect></aop:config></beans>

沒增強(qiáng)前結(jié)果展示：

增強(qiáng)之后結(jié)果展示：