Spring Aop实例

在上篇博文中，我向大家介绍了Aop重要概念和教程，这回给出代码示例。

一、XML方式

1. TestAspect：切面类

package com.spring.aop;import org.aspectj.lang.JoinPoint;import org.aspectj.lang.ProceedingJoinPoint;public class TestAspect {public void doAfter(JoinPoint jp) {System.out.println("log Ending method: " + jp.getTarget().getClass().getName() + "." + jp.getSignature().getName());}public Object doAround(ProceedingJoinPoint pjp) throws Throwable {long time = System.currentTimeMillis();Object retVal = pjp.proceed();time = System.currentTimeMillis() - time;System.out.println("process time: " + time + " ms");return retVal;}public void doBefore(JoinPoint jp) {System.out.println("log Begining method: " + jp.getTarget().getClass().getName() + "." + jp.getSignature().getName());}public void doThrowing(JoinPoint jp, Throwable ex) {System.out.println("method " + jp.getTarget().getClass().getName() + "." + jp.getSignature().getName() + " throw exception");System.out.println(ex.getMessage());}}

2. AServiceImpl：目标对象

package com.spring.service;// 使用jdk动态代理public class AServiceImpl implements AService {public void barA() {System.out.println("AServiceImpl.barA()");}public void fooA(String _msg) {System.out.println("AServiceImpl.fooA(msg:" + _msg + ")");}}

3. BServiceImpl：目标对象

package com.spring.service;// 使用cglibpublic class BServiceImpl {public void barB(String _msg, int _type) {System.out.println("BServiceImpl.barB(msg:" + _msg + " type:" + _type + ")");if (_type == 1)throw new IllegalArgumentException("测试异常");}public void fooB() {System.out.println("BServiceImpl.fooB()");}}

4. ApplicationContext：Spring配置文件

<?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"xmlns:context="http://www.springframework.org/schema/context"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">    <aop:config>        <aop:aspect id="TestAspect" ref="aspectBean">            <!--配置com.spring.service包下所有类或接口的所有方法-->            <aop:pointcut id="businessService" expression="execution(* com.spring.service.*.*(..))" />            <aop:before pointcut-ref="businessService" method="doBefore"/>            <aop:after pointcut-ref="businessService" method="doAfter"/>            <aop:around pointcut-ref="businessService" method="doAround"/>            <aop:after-throwing pointcut-ref="businessService" method="doThrowing" throwing="ex"/>        </aop:aspect>    </aop:config>        <bean id="aspectBean" class="com.spring.aop.TestAspect" />    <bean id="aService" class="com.spring.service.AServiceImpl"></bean>    <bean id="bService" class="com.spring.service.BServiceImpl"></bean></beans>

二、注解（Annotation）方式

1. TestAnnotationAspect

package com.spring.aop;import org.aspectj.lang.ProceedingJoinPoint;import org.aspectj.lang.annotation.After;import org.aspectj.lang.annotation.AfterReturning;import org.aspectj.lang.annotation.AfterThrowing;import org.aspectj.lang.annotation.Around;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.aspectj.lang.annotation.Pointcut;@Aspectpublic class TestAnnotationAspect {@Pointcut("execution(* com.spring.service.*.*(..))")private void pointCutMethod() {}//声明前置通知@Before("pointCutMethod()")public void doBefore() {System.out.println("前置通知");}//声明后置通知@AfterReturning(pointcut = "pointCutMethod()", returning = "result")public void doAfterReturning(String result) {System.out.println("后置通知");System.out.println("---" + result + "---");}//声明例外通知@AfterThrowing(pointcut = "pointCutMethod()", throwing = "e")public void doAfterThrowing(Exception e) {System.out.println("例外通知");System.out.println(e.getMessage());}//声明最终通知@After("pointCutMethod()")public void doAfter() {System.out.println("最终通知");}//声明环绕通知@Around("pointCutMethod()")public Object doAround(ProceedingJoinPoint pjp) throws Throwable {System.out.println("进入方法---环绕通知");Object o = pjp.proceed();System.out.println("退出方法---环绕通知");return o;}}

2. ApplicationContext：Spring配置文件

<?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"xmlns:context="http://www.springframework.org/schema/context"xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsdhttp://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsdhttp://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">    <aop:aspectj-autoproxy></aop:aspectj-autoproxy>    <bean class="org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator" />    <bean id="aspectBean" class="com.spring.aop.TestAnnotationAspect" />    <bean id="aService" class="com.spring.service.AServiceImpl"></bean>    <bean id="bService" class="com.spring.service.BServiceImpl"></bean></beans>

关于切入点表达式，大家需要好好练习才能深入理解其中含义。即使看的懂，但是写起来却非常麻烦，并没有想象中那么简单。

最后，再告诉大家：

任何通知（Advice）方法可以将第一个参数定义为 org.aspectj.lang.JoinPoint类型。JoinPoint接口提供了一系列有用的方法， 比如 getArgs() （返回方法参数）、getThis() （返回代理对象）、getTarget() （返回目标）、getSignature() （返回正在被通知的方法相关信息）和 toString() （打印出正在被通知的方法的有用信息。

其中getSignature()返回的Signature对象可强制转换为MethodSignature，其功能非常强大，能获取包括参数名称在内的一切方法信息。

============友情链接============

Spring Aop详尽教程 http://blog.csdn.net/wangpeng047/article/details/8556800