获取更详细的 Spring Bean 初始化异常答案

【问题标题】：Get more detailed Spring Bean Initialization Exceptions获取更详细的 Spring Bean 初始化异常
【发布时间】：2015-10-22 12:47:20
【问题描述】：

我在启动 Tomcat 时遇到这样的异常：

java.lang.NoClassDefFoundError: com/mycompany/mypackage/SomeClass
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getDeclaredMethods(Unknown Source)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.buildLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:194)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.findLifecycleMetadata(InitDestroyAnnotationBeanPostProcessor.java:176)
at org.springframework.beans.factory.annotation.InitDestroyAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(InitDestroyAnnotationBeanPostProcessor.java:122)
at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessMergedBeanDefinition(CommonAnnotationBeanPostProcessor.java:283)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyMergedBeanDefinitionPostProcessors(AbstractAutowireCapableBeanFactory.java:870)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:495)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:296)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:293)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:410)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:306)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:5003)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5517)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1263)
at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1948)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.mycompany.mypackage.SomeClass
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1858)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1709)
... 33 more

因此，这意味着，某些 bean 无法被 Spring 初始化，因为它直接（或更糟糕的是，间接）引用了 com.mycompany.mypackage.SomeClass 类

我发现这个 Stacktrace 很糟糕，因为它说明了症状，但不是根本原因。我需要知道哪个 bean 没有被初始化，所以我可以与负责该 bean 的人交谈，以便他决定“SomeClass”是否应该在类路径中。

有什么技巧可以找出没有初始化的bean吗？

【问题讨论】：

How to show detail of Exception causes in log files的可能重复
@WornOutSoles，其实不是重复的。我宁愿删除另一个问题，因为它不准确，我问错了问题。编辑另一个问题以使其像这样会使现有答案无效，因此我更愿意对坏问题进行近距离投票。
您可以在创建之前修改其他问题。无论如何，没关系;-)

标签： java spring classnotfoundexception spring-bean

【解决方案1】：

在org.springframework 上将日志记录级别设置为debug，您将获得有关此异常发生位置的更详细的日志。

【讨论】：

【解决方案2】：

我在识别失败的 bean 时从来没有遇到过任何问题，它们总是出现在您的 log4j 文件中。它显示了错误的确切原因，例如：

o.s.w.s.DispatcherServlet ERROR - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'homeController' defined in file [...\HomeController.class]: Instantiation of bean failed; nested exception is java.lang.ExceptionInInitializerError
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:1095)
    ...
    Caused by: java.lang.ClassNotFoundException: NonExistent
    at java.lang.Class.forName(Class.java:240)
    at .......HomeController.<clinit>(HomeController.java:17)

【讨论】：