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;
-
- 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;
-
- public 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.xsd
- http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
- http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
- http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">
- <aop:config>
- <aop:aspect id="TestAspect" ref="aspectBean">
-
- <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;
-
- @Aspect
- public class TestAnnotationAspect {
-
- @Pointcut("execution(* com.spring.service.*.*(..))")
- private void pointCutMethod() {
- }
-
-
- @Before("pointCutMethod()")
- public void doBefore() {
- System.out.println("前置通知");
- }
-
-
- @AfterReturning(pointcut = "pointCutMethod()", returning = "result")
- public void doAfterReturning(String result) {
- System.out.println("后置通知");
- System.out.println("---" + result + "---");
- }
-
-
- @AfterThrowing(pointcut = "pointCutMethod()", throwing = "e")
- public void doAfterThrowing(Exception e) {
- System.out.println("例外通知");
- System.out.println(e.getMessage());
- }
-
-
- @After("pointCutMethod()")
- public void doAfter() {
- System.out.println("最终通知");
- }
-
-
- @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:
- http:
- http:
- http:
- <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。
Spring Aop实例
原文：http://www.cnblogs.com/yepei/p/4735301.html
