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我正在尝试在我的应用程序中实现日志记录方面。这是我第一次尝试 AOP，所以如果我遗漏了一些明显的东西，请告诉我。为了实现编织外部罐子，我正在尝试实现加载时间编织器。我确实在我的应用程序上下文中指定了加载时间编织器，并在我的 context.xml 文件中提到了 TomcatInstrumentableClassLoader 以及 aop.xml。我的应用程序是一个 Spring MVC REST 应用程序，并且也使用了 JAXB 内容协商。在应用程序启动期间，从我提到的类构建 JAXBContext 时，JAXB 出错并出现空指针异常。但是，如果没有 TomcatInstrumentableClassLoader，JAXBContext 会正常初始化，一切正常。但是，没有 TomcatInstrumentableClassLoader 加载时间编织将无法工作。我能做些什么来解决这个问题吗？任何帮助是极大的赞赏。

我的应用上下文：

    ....
    <aop:aspectj-autoproxy/>
    <context:load-time-weaver aspectj-weaving="on" />
    .....
    <oxm:jaxb2-marshaller id="jaxb2Marshaller">
    <oxm:class-to-be-bound name="core.jaxb.DocPackage"/>
    <oxm:class-to-be-bound name="core.jaxb.life.Life"/>
    <oxm:class-to-be-bound name="core.jaxb.corr.Corr"/>
    <oxm:class-to-be-bound name="core.jaxb.ps.PS"/>
</oxm:jaxb2-marshaller>

这是我的 context.xml：

    <?xml version="1.0" encoding="UTF-8"?>
    <Context>
<Loader loaderClass="org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader" useSystemClassLoaderAsParent="false"/>
</Context>

我的 aop.xml：

     <!DOCTYPE aspectj PUBLIC
    "-//AspectJ//DTD//EN" "http://www.eclipse.org/aspectj/dtd/aspectj.dtd">
    <aspectj>
<weaver>
    <!-- only weave classes in our application-specific packages -->
    <include within="core.aspects.*"/>
</weaver>
<aspects>
    <!-- weave in just this aspect -->        
    <aspect name="core.aspects.LoggerAspect"/>
</aspects>

这是堆栈跟踪：

    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jaxb2Marshaller': Invocation of init method failed; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1420)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:844)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:786)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:703)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:478)
... 23 more
     Caused by: java.lang.NullPointerException
at java.util.EnumMap.<init>(EnumMap.java:113)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeEnumLeafInfoImpl.<init>(RuntimeEnumLeafInfoImpl.java:72)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.createEnumLeafInfo(RuntimeModelBuilder.java:94)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.createEnumLeafInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:213)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:89)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:198)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:84)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:304)
at com.sun.xml.internal.bind.v2.model.impl.SingleTypePropertyInfoImpl.getTarget(SingleTypePropertyInfoImpl.java:79)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeValuePropertyInfoImpl.getTarget(RuntimeValuePropertyInfoImpl.java:55)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeValuePropertyInfoImpl.getTarget(RuntimeValuePropertyInfoImpl.java:39)
at com.sun.xml.internal.bind.v2.model.impl.SingleTypePropertyInfoImpl.ref(SingleTypePropertyInfoImpl.java:73)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeValuePropertyInfoImpl.ref(RuntimeValuePropertyInfoImpl.java:59)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeValuePropertyInfoImpl.ref(RuntimeValuePropertyInfoImpl.java:39)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:244)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:89)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:198)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:84)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:304)
at com.sun.xml.internal.bind.v2.model.impl.TypeRefImpl.calcRef(TypeRefImpl.java:81)
at com.sun.xml.internal.bind.v2.model.impl.TypeRefImpl.getTarget(TypeRefImpl.java:58)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeTypeRefImpl.getTarget(RuntimeTypeRefImpl.java:47)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeTypeRefImpl.getTarget(RuntimeTypeRefImpl.java:40)
at com.sun.xml.internal.bind.v2.model.impl.ElementPropertyInfoImpl$1.get(ElementPropertyInfoImpl.java:63)
at com.sun.xml.internal.bind.v2.model.impl.ElementPropertyInfoImpl$1.get(ElementPropertyInfoImpl.java:61)
at java.util.AbstractList$Itr.next(AbstractList.java:345)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:244)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:89)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getClassInfo(ModelBuilder.java:198)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:84)
at com.sun.xml.internal.bind.v2.model.impl.RuntimeModelBuilder.getClassInfo(RuntimeModelBuilder.java:70)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:304)
at com.sun.xml.internal.bind.v2.model.impl.ModelBuilder.getTypeInfo(ModelBuilder.java:319)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:430)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:277)
at com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1100)
at com.sun.xml.internal.bind.v2.ContextFactory.createContext(ContextFactory.java:143)
at com.sun.xml.internal.bind.v2.ContextFactory.createContext(ContextFactory.java:110)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at javax.xml.bind.ContextFinder.newInstance(ContextFinder.java:202)
at javax.xml.bind.ContextFinder.find(ContextFinder.java:376)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:574)
at javax.xml.bind.JAXBContext.newInstance(JAXBContext.java:522)
at org.springframework.oxm.jaxb.Jaxb2Marshaller.createJaxbContextFromClasses(Jaxb2Marshaller.java:372)
at org.springframework.oxm.jaxb.Jaxb2Marshaller.getJaxbContext(Jaxb2Marshaller.java:331)
at org.springframework.oxm.jaxb.Jaxb2Marshaller.afterPropertiesSet(Jaxb2Marshaller.java:317)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1477)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1417)
... 33 more
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1 回答 1

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哇 - 大量的日志记录实现！这是我用来取得巨大成功的策略：

  1. 创建一个用 AspectJ@Aspect注释和 Spring@Component注释注释的方面，因为一个使它成为一个方面，后者使它成为一个 Spring bean
  2. 通过配置 Speing AOP 命名空间，在您的应用程序中启用方面，然后设置<aop:aspectj-autoproxy>
  3. 在切面中创建一个方法，使用 注释，@Around以便它在处理程序方法执行之前和之后运行。将方法配置为仅对 Controller 包中的类运行，如下所示：@Around("execution(* com.mycontrollerpackage.(.*(..))")

现在您有了一个在方法执行之前和之后运行的方面，允许您记录有关请求的信息，从传入的内容到花费的时间。你还可以执行安全检查，设置ThreadLocal变量来指导执行等等各种好东西。

于 2011-07-14T02:29:21.977 回答