spring aop的五大通知类

大家好，又见面了，我是你们的朋友全栈君。

spring aop通知(advice)分成五类：

• 前置通知[Before advice]@Before：在连接点前面执行，前置通知不会影响连接点的执行，除非此处抛出异常。
• 后置通知、正常返回通知[After returning advice]@AfterReturning：在连接点正常执行完成后执行，如果连接点抛出异常，则不会执行；与环绕通知同时使用时，会受环绕通知的影响。
• 异常通知、异常返回通知[After throwing advice]@AfterThrowing：在连接点抛出异常后执行。
• 最终通知、返回通知[After (finally) advice]@After：在连接点执行完成后执行，不管是正常执行完成，还是抛出异常，都会执行返回通知中的内容。
• 环绕通知[Around advice]@Around：环绕通知围绕在连接点前后，比如一个方法调用的前后。这是最强大的通知类型，能在方法调用前后自定义一些操作。环绕通知还需要负责决定是继续处理join point(调用ProceedingJoinPoint的proceed方法)还是中断执行。
  
  pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>groupId</groupId>
<artifactId>dome03</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.1.5.RELEASE</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.1.5.RELEASE</version>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>3.1</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.2</version>
</dependency>
</dependencies>
</project>

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:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xsi:schemaLocation=" http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
<context:component-scan base-package="com.xbj"/>
<aop:config proxy-target-class="true">
<aop:aspect ref="myAdvices">
<aop:pointcut id="pc" expression="execution(* com.xbj.service.impl.*.*(..))"/>
<aop:before method="before" pointcut-ref="pc" />
<aop:after-returning method="afterRunturn" pointcut-ref="pc" />
<aop:after method="afterfinally" pointcut-ref="pc" />
<aop:around method="around" pointcut-ref="pc" />
<!--ex 要和 切面的 参数签名一致-->
<aop:after-throwing method="afterThorw" pointcut-ref="pc" throwing="ex" />
</aop:aspect>
</aop:config>
</beans>

UserController.java

package com.xbj.controller;
import com.xbj.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
/* @Controller @Repository @Component @Service 都是将bean放入Ioc容器中，只是为了代码的可读性而去区别开 * @Autowired 是从Ioc容器拿对象 * */
@Controller
public class UserController { 

@Autowired
private UserService userService;
public void addUser(){ 

userService.addUser();
}
}

UserDao.java

package com.xbj.dao;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
public interface UserDao { 

void addUser();
void delUser();
}

UserDaoImpl.java

package com.xbj.dao.impl;
import com.xbj.dao.UserDao;
import org.junit.runner.RunWith;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
@Repository
public class UserDaoImpl implements UserDao { 

public void addUser() { 

System.out.println("addUser");
}
public void delUser() { 

System.out.println("delUser");
}
//定义初始化方法
public void myInit(){ 

System.out.println("init...");
}
//定义销毁方法
public void dest(){ 

System.out.println("dest...");
}
}

UserService.java

package com.xbj.service;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
public interface UserService { 

void addUser();
void delUser();
}

UserServiceImpl.java

package com.xbj.service.impl;
import com.xbj.dao.UserDao;
import com.xbj.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
@Service
public class UserServiceImpl implements UserService { 

@Autowired
private UserDao userDao;
public void addUser() { 

userDao.addUser();
}
public void delUser() { 

userDao.delUser();
}
}

MyAdvices.java

package com.xbj;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.springframework.stereotype.Component;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
/* * 注意类的包名 * */
@Component
public class MyAdvices { 

//前置通知
public void before(JoinPoint joinpoint){ 

System.out.println("前置通知");
}
//正常放回通知
public void afterRunturn(JoinPoint joinpoint){ 

System.out.println("afterRunturn");
}
//最终返回通知
public void afterfinally(JoinPoint joinpoint){ 

System.out.println("afterfinally");
}
//环绕通知
public void around(ProceedingJoinPoint proceedingJoinPoint){ 

System.out.println("around-before");
try { 

proceedingJoinPoint.proceed();
} catch (Throwable throwable) { 

throwable.printStackTrace();
}
System.out.println("around-after");
}
//异常通知
public void afterThorw(Throwable ex){ 

System.out.println("afterThorw"+ex);
}
}

test.java

import com.xbj.controller.UserController;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
/** * @Author:晓宇码匠 * @Date：2019/6/15 0015 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { 
"classpath:applicationContext.xml"})
public class test { 

@Autowired
private UserController controller;
@Test
public void t1() { 

controller.addUser();
}
}

控制台输出：

前置通知
around-before
addUser
around-after
afterfinally
afterRunturn