通知advice

基于注解的Spring AOP开发，来自https://www.cnblogs.com/junzi2099/p/8274813.html

1.定义目标类接口和实现类

2.编写Spring AOP的aspect 类

@Aspect
public class MyAspect {

    /**
     * 前置通知
     */
    @Before("execution(* com.zejian.spring.springAop.dao.UserDao.addUser(..))")
    public void before(){
        System.out.println("前置通知....");
    }

    /**
     * 后置通知
     * returnVal,切点方法执行后的返回值
     */
    @AfterReturning(value="execution(* com.zejian.spring.springAop.dao.UserDao.addUser(..))",returning = "returnVal")
    public void AfterReturning(Object returnVal){
        System.out.println("后置通知...."+returnVal);
    }


    /**
     * 环绕通知
     * @param joinPoint 可用于执行切点的类
     * @return
     * @throws Throwable
     */
    @Around("execution(* com.zejian.spring.springAop.dao.UserDao.addUser(..))")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        System.out.println("环绕通知前....");
        Object obj= (Object) joinPoint.proceed();
        System.out.println("环绕通知后....");
        return obj;
    }

    /**
     * 抛出通知
     * @param e
     */
    @AfterThrowing(value="execution(* com.zejian.spring.springAop.dao.UserDao.addUser(..))",throwing = "e")
    public void afterThrowable(Throwable e){
        System.out.println("出现异常:msg="+e.getMessage());
    }

    /**
     * 无论什么情况下都会执行的方法
     */
    @After(value="execution(* com.zejian.spring.springAop.dao.UserDao.addUser(..))")
    public void after(){
        System.out.println("最终通知....");
    }
}

3.编写配置文件交由Spring IOC容器管理

<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"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 启动@aspectj的自动代理支持-->
    <aop:aspectj-autoproxy />

    <!-- 定义目标对象 -->
    <bean id="userDaos" class="com.zejian.spring.springAop.dao.daoimp.UserDaoImp" />
    <!-- 定义aspect类 -->
    <bean name="myAspectJ" class="com.zejian.spring.springAop.AspectJ.MyAspect"/>
</beans>

4.编写测试类

/**
 * Created by zejian on 2017/2/19.*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations= "classpath:spring/spring-aspectj.xml")
public class UserDaoAspectJ {
    @Autowired
    UserDao userDao;

    @Test
    public void aspectJTest(){
        userDao.addUser();
    }
}

5.结果

　　

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