峰Spring4学习（6）spring AOP的应用例子

一、AOP简介：

二、AOP实例：

三、使用的例子

需求：在student添加的前后，打印日志信息；

0）spring AOP需要引用的jar包：

1）StudentService.java接口：

package com.cy.service;

public interface StudentService {

    public void addStudent(String name);

}

2）StudentServiceImpl.java实现类：

package com.cy.service.impl;

import com.cy.service.StudentService;

public class StudentServiceImpl implements StudentService {

    @Override

    public void addStudent(String name) {

        System.out.println("添加学生"+name);

    }

}

3）StudentServiceAspect.java切面类：

package com.cy.advice;

import org.aspectj.lang.JoinPoint;

import org.aspectj.lang.ProceedingJoinPoint;

public class StudentServiceAspect {

    //前置通知，方法执行之前

    public void doBefore(JoinPoint jp){

        System.out.println("类名：" + jp.getTarget().getClass().getName());

        System.out.println("方法名：" + jp.getSignature().getName());

        System.out.println("开始添加学生：" + jp.getArgs()[0]);

    }

    //后置通知 方法完成之后

    public void doAfter(JoinPoint jp){

        System.out.println("类名：" + jp.getTarget().getClass().getName());

        System.out.println("方法名：" + jp.getSignature().getName());

        System.out.println("完成添加学生：" + jp.getArgs()[0]);

    }

    //环绕通知  可以在业务方法的前后添加逻辑

    public Object doAround(ProceedingJoinPoint pjp) throws Throwable{

        System.out.println("添加学生前");

        Object retVal = pjp.proceed();    //retVal为StudentServiceImpl.addStudent(String name)方法的返回值

                                          //因为返回值为void，所以console打印null

        System.out.println("添加学生后");

        System.out.println(retVal);

        return retVal;

    }

    //返回通知

    public void doAfterReturning(JoinPoint jp){

        System.out.println("返回通知");

    }

    //异常通知

    public void doAfterThrowing(JoinPoint jp, Throwable ex){

        System.out.println("异常通知");

        System.out.println("异常信息：" + ex.getMessage());

    }

}

4）beans.xml配置：

<?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

                  http://www.springframework.org/schema/beans/spring-beans.xsd

                  http://www.springframework.org/schema/aop

                   http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

     <bean id="studentService" class="com.cy.service.impl.StudentServiceImpl"></bean>

     <bean id="studentServiceAspect" class="com.cy.advice.StudentServiceAspect"></bean>

     <aop:config>

         <aop:aspect id="studentServiceAspect" ref="studentServiceAspect">

             <aop:pointcut expression="execution(* com.cy.service..*.*(..))" id="businessService"/>

             <aop:before method="doBefore" pointcut-ref="businessService"/>

             <aop:after method="doAfter" pointcut-ref="businessService"/>

             <aop:around method="doAround" pointcut-ref="businessService"/>

             <aop:after-returning method="doAfterReturning" pointcut-ref="businessService"/>

             <aop:after-throwing method="doAfterThrowing" pointcut-ref="businessService" throwing="ex"/>

         </aop:aspect>

     </aop:config>

</beans>

5）测试代码：

public class T {

    public static void main(String[] args) {

        ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");

        StudentService studentService = (StudentService) ac.getBean("studentService");

        studentService.addStudent("张三");

    }

}

1）没有异常抛出时，没有异常通知；console打印：

2）addStudent方法中构造异常，有异常通知，console打印：

StudentServiceImpl.java:

package com.cy.service.impl;

import com.cy.service.StudentService;

public class StudentServiceImpl implements StudentService {

    @Override

    public void addStudent(String name) {

        System.out.println("添加学生"+name);

        System.out.println(1/0);

    }

}

doAround方法中抛出异常是这句话：

-- Object retVal = pjp.proceed();

巴特西

峰Spring4学习（6）spring AOP的应用例子

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