spring aop（面向切面） 详解

一，xml 方式：

<?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" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd" default-autowire="default" default-lazy-init="false">

<context:annotation-config></context:annotation-config>
<context:component-scan base-package="spring"></context:component-scan>

<bean id="xmlAopTest" class="spring.aop.xml.XmlAopTest"></bean>

<aop:config>
<aop:aspect ref="xmlAopTest">
<aop:pointcut expression="execution(* spring.aop.target..*.*(..))" id="xmlAop"/>
<aop:before pointcut-ref="xmlAop" method="beforeMethod" />
<aop:after method="afterMethod" pointcut-ref="xmlAop"/>
<aop:after-returning method="afterReturnMethod" pointcut-ref="xmlAop" returning="resultVal"/>
<aop:after-throwing method="afterThrowingMethod" pointcut-ref="xmlAop" throwing="ex"/>
<aop:around method="aroundMethod" pointcut-ref="xmlAop"/>
</aop:aspect>
</aop:config>
</beans>

package spring.aop.xml;

import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;

/**
* xml形式 aop 配置
* @author wwp
*
*/
public class XmlAopTest {

private Logger log = Logger.getLogger(getClass());

/**
* 前置通知
*/
public void beforeMethod(JoinPoint jp){
System.out.println("这是前置通知");
}

/**
* 后置通知
*/
public void afterMethod(JoinPoint jp){
System.out.println("这是一个后置通知");
}

/**
* 返回后通知
*/
public void afterReturnMethod(JoinPoint jp, Object resultVal){
log.info("这是返回后通知, returning: " + resultVal);
}

/**
* 异常抛出后通知
*/
public void afterThrowingMethod(JoinPoint jp, Throwable ex){
log.info("异常抛出后通知");
}

/**
* 环绕通知
* @throws Throwable
*/
public void aroundMethod(ProceedingJoinPoint pjp) throws Throwable{
log.info("环绕通知前");
pjp.proceed();
log.info("环绕通知后");
}
}

package spring;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import spring.aop.target.Target;

public class Test {

public static void main(String[] args) {
ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
Target target = (Target) ac.getBean("target");
target.sum(3, 6);
}
}

2016-10-07 04:20:34,907 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - <Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@2bb57fd1: startup date [Fri Oct 07 04:20:34 CST 2016]; root of context hierarchy>
2016-10-07 04:20:34,982 INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - <Loading XML bean definitions from class path resource [applicationContext.xml]>
2016-10-07 04:20:35,796 INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - <Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@b10b9b2: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,target,springTestDao,springTestService,xmlAopTest,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.aop.aspectj.AspectJPointcutAdvisor#0,org.springframework.aop.aspectj.AspectJPointcutAdvisor#1,org.springframework.aop.aspectj.AspectJPointcutAdvisor#2,org.springframework.aop.aspectj.AspectJPointcutAdvisor#3,org.springframework.aop.aspectj.AspectJPointcutAdvisor#4,xmlAop,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy>
2016-10-07 04:20:36,126 INFO [spring.dao.impl.SpringTestDao] - <SpringTestDao constructor !!!>
这是前置通知
2016-10-07 04:20:36,156 INFO [spring.aop.xml.XmlAopTest] - <环绕通知前>
2016-10-07 04:20:36,185 INFO [spring.aop.xml.XmlAopTest] - <异常抛出后通知>
这是一个后置通知
Exception in thread "main" java.lang.RuntimeException: aop运行时异常
at spring.aop.target.Target.sum(Target.java:11)
at spring.aop.target.Target$$FastClassBySpringCGLIB$$d6d00021.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:700)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80)
at spring.aop.xml.XmlAopTest.aroundMethod(XmlAopTest.java:50)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMeth
10a97
odInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterThrowingAdvice.invoke(AspectJAfterThrowingAdvice.java:55)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.adapter.AfterReturningAdviceInterceptor.invoke(AfterReturningAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.aspectj.AspectJAfterAdvice.invoke(AspectJAfterAdvice.java:42)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:633)
at spring.aop.target.Target$$EnhancerBySpringCGLIB$$95845339.sum(<generated>)
at spring.Test.main(Test.java:12)

二， 注解的方式

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:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd" default-autowire="default" default-lazy-init="false">

<context:annotation-config></context:annotation-config>
<context:component-scan base-package="spring"></context:component-scan>
<aop:aspectj-autoproxy></aop:aspectj-autoproxy> <!-- 必须 -->

</beans>

package spring.aop.annotation;

import org.apache.log4j.Logger;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

/**
* aop使用注解方式
* @author wwp
*
*/
@Aspect
@Component
public class AnnotationAopTest {

private Logger log = Logger.getLogger(getClass());

/**
* 定义切入点（有异常）
*/
@Pointcut("execution(* spring.aop.target..*(..))")
public void pointcut(){};

/**
* 前置通知
*/
@Before("execution(* spring.aop.target..*(..))")
public void before(JoinPoint joinPoint){
System.out.println("前置通知");
}

}

2016-10-07 05:00:49,877 INFO [org.springframework.context.support.ClassPathXmlApplicationContext] - <Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@3348854d: startup date [Fri Oct 07 05:00:49 CST 2016]; root of context hierarchy>
2016-10-07 05:00:49,952 INFO [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - <Loading XML bean definitions from class path resource [applicationContext.xml]>
2016-10-07 05:00:50,789 INFO [org.springframework.beans.factory.support.DefaultListableBeanFactory] - <Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@136fdd2d: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.internalPersistenceAnnotationProcessor,annotationAopTest,target,springTestDao,springTestService,org.springframework.aop.config.internalAutoProxyCreator,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy>
2016-10-07 05:00:51,074 INFO [spring.dao.impl.SpringTestDao] - <SpringTestDao constructor !!!>
前置通知
Exception in thread "main" java.lang.RuntimeException: aop运行时异常
at spring.aop.target.Target.sum(Target.java:11)
at spring.aop.target.Target$$FastClassBySpringCGLIB$$d6d00021.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:700)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:51)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:633)
at spring.aop.target.Target$$EnhancerBySpringCGLIB$$2caebf5.sum(<generated>)
at spring.Test.main(Test.java:12)

三，待处理问题：

1，afterReturing 的具体使用
2，注解使用共用pointcut 报错
3，如果需要在controller 层使用aop ，必须在 servlet 配置文件中加上 <aop:aspectj-autoproxy/> <!-- 必须 -->