spring 面向切口编程出现的一个bug折磨了我好久啊！！



java.lang.ExceptionInInitializerError

	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)

	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)

	at java.lang.reflect.Constructor.newInstance(Unknown Source)

	at org.junit.internal.runners.TestClassMethodsRunner.createTest(TestClassMethodsRunner.java:52)

	at org.junit.internal.runners.TestClassMethodsRunner.invokeTestMethod(TestClassMethodsRunner.java:58)

	at org.junit.internal.runners.TestClassMethodsRunner.run(TestClassMethodsRunner.java:35)

	at org.junit.internal.runners.TestClassRunner$1.runUnprotected(TestClassRunner.java:42)

	at org.junit.internal.runners.BeforeAndAfterRunner.runProtected(BeforeAndAfterRunner.java:34)

	at org.junit.internal.runners.TestClassRunner.run(TestClassRunner.java:52)

	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)

	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)

	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)

	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)

	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDAOImpl' defined in file [D:\spingWorkSpace\Spring_08_annotation_component\bin\com\huanghui\daoImpl\UserDAOImpl.class]: BeanPostProcessor before instantiation of bean failed; nested exception is java.lang.NullPointerException

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:405)

	at java.security.AccessController.doPrivileged(Native Method)

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)

	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)

	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)

	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)

	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)

	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)

	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429)

	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728)

	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:380)

	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)

	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)

	at com.huanghui.service.UserServiceTest.<clinit>(UserServiceTest.java:12)

	... 16 more

Caused by: java.lang.NullPointerException

	at org.aspectj.weaver.WeakClassLoaderReference.<init>(WeakClassLoaderReference.java:45)

	at org.aspectj.weaver.tools.PointcutParser.setClassLoader(PointcutParser.java:228)

	at org.aspectj.weaver.tools.PointcutParser.<init>(PointcutParser.java:215)

	at org.aspectj.weaver.tools.PointcutParser.getPointcutParserSupportingSpecifiedPrimitivesAndUsingContextClassloaderForResolution(PointcutParser.java:130)

	at org.springframework.aop.aspectj.AspectJExpressionPointcut.<init>(AspectJExpressionPointcut.java:123)

	at org.springframework.aop.aspectj.AspectJExpressionPointcut.<init>(AspectJExpressionPointcut.java:136)

	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.getPointcut(ReflectiveAspectJAdvisorFactory.java:144)

	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.getAdvisor(ReflectiveAspectJAdvisorFactory.java:129)

	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory$1.doWith(ReflectiveAspectJAdvisorFactory.java:74)

	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:466)

	at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:443)

	at org.springframework.aop.aspectj.annotation.ReflectiveAspectJAdvisorFactory.getAdvisors(ReflectiveAspectJAdvisorFactory.java:70)

	at org.springframework.aop.aspectj.annotation.BeanFactoryAspectJAdvisorsBuilder.buildAspectJAdvisors(BeanFactoryAspectJAdvisorsBuilder.java:110)

	at org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator.findCandidateAdvisors(AnnotationAwareAspectJAutoProxyCreator.java:85)

	at org.springframework.aop.aspectj.autoproxy.AspectJAwareAdvisorAutoProxyCreator.shouldSkip(AspectJAwareAdvisorAutoProxyCreator.java:105)

	at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessBeforeInstantiation(AbstractAutoProxyCreator.java:281)

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:791)

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.resolveBeforeInstantiation(AbstractAutowireCapableBeanFactory.java:762)

	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:399)

	... 29 more

bug --------------------编程问答-------------------- UserDAOImpl 找找看是否创建成功 --------------------编程问答-------------------- 您好，类创建好了，就是不能引进AOP，如果不用@aspect这个注解就能运行，可是加上这个注解，就报上面的错误，我估计可能是环境问题引起的，可是无法解决！ --------------------编程问答-------------------- LZ,你是用标记去创建自己的AOP切割类吧,那检查下有没有这些:

spring.xml
(1)增加<aop:aspectj-autoproxy/>
(2)增加<context:component-scan base-package="切割类包名" />

XXX.java
(3)在头顶上@Aspect的下面增加一下@Component(spring扫描标记)
然后再试试
--------------------编程问答-------------------- 这个有小demo
http://download.csdn.net/detail/zuxianghuang/4138590 --------------------编程问答-------------------- 还要是pointcut吧 --------------------编程问答--------------------



<!-- 参与缓存的切入点对象 (切入点对象，确定何时何地调用拦截器) -->

	<bean class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">

		<!-- 配置缓存切面 -->

		<property name="advice" ref="cacheMethodInterceptor" />

		<!--

			配置哪些方法参与缓存策略 .表示符合任何单一字元 ### +表示符合前一个字元一次或多次 ### *表示符合前一个字元零次或多次 ###

			\Escape任何Regular expression使用到的符号

		-->

		<!-- .*表示前面的前缀(包括包名) 表示print方法-->

		<property name="patterns">

			<list>

				<value>

					<!-- com.shadow.mvc.service\..Service.*\.find.*   -->

					com.shadow.mvc.service.impl.BrandService.*\.find.*

				</value>

			</list>

		</property>

	</bean>



	<aop:config></aop:config>



	<!-- 配置一个缓存拦截器对象，处理具体的同步缓存业务 -->

	<bean id="cacheMethodAfterAdvice" class="com.shadow.extras.cache.CacheMethodAfterAdvice">

		<property name="memCachedClient" ref="memCachedClient" />

	</bean>

	<aop:config>

		<aop:aspect id="methodCachePointCutAdviceAspect" ref="cacheMethodAfterAdvice">

			<aop:after method="afterReturning"

				pointcut="execution(* com.shadow.mvc.service.*Service.modify*(..))" />

			<aop:after method="afterReturning"

				pointcut="execution(* com.shadow.mvc.service.*Service.save*(..))" />

			<aop:after method="afterReturning"

				pointcut="execution(* com.shadow.mvc.service.*Service.remove*(..))" />

		</aop:aspect>

	</aop:config>



<!-- 开启代理模式 -->

	<!-- <aop:aspectj-autoproxy proxy-target-class="true"/>  -->

	<aop:aspectj-autoproxy />



	<!--

		enable component scanning (beware that this does not enable mapper

		scanning!)

	-->

	<context:component-scan base-package="com.shadow" />

要开启模式 --------------------编程问答-------------------- 问题找到了，原来是我的扎包user liblary设置成了System扎了！蛋疼啊！

补充：Java ,  Java EE