Spring启动创建keyManagementResource Bean失败缺失ELManager排查

项目启动时抛出上下文初始化监听器异常，对应子模块未成功加载，Postman调用接口返回404状态码，完整错误日志如下：

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'keyManagementResource': Unsatisfied dependency expressed through field 'keyValidatorFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'keyValidatorFactory' defined in class path resource [key-mgmt-context.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: javax/el/ELManager
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1257)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:551)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:481)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:756)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:443)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:325)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:107)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:750)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'keyValidatorFactory' defined in class path resource [key-mgmt-context.xml]: Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: javax/el/ELManager
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1619)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:481)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:312)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:308)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:211)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1134)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1062)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
    ... 24 more
Caused by: java.lang.NoClassDefFoundError: javax/el/ELManager
    at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.buildExpressionFactory(ResourceBundleMessageInterpolator.java:171)
    at org.hibernate.validator.messageinterpolation.ResourceBundleMessageInterpolator.<init>(ResourceBundleMessageInterpolator.java:94)
    at org.hibernate.validator.internal.engine.AbstractConfigurationImpl.getDefaultMessageInterpolator(AbstractConfigurationImpl.java:573)
    at org.springframework.validation.beanvalidation.LocalValidatorFactoryBean.afterPropertiesSet(LocalValidatorFactoryBean.java:271)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1677)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1615)
    ... 34 more
Caused by: java.lang.ClassNotFoundException: javax.el.ELManager
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    ... 40 more

Jul 06, 2022 4:48:22 PM org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart
Jul 06, 2022 4:48:22 PM org.apache.catalina.core.StandardContext startInternal

• 整体项目基于Vert.x框架开发
• 故障出现在单个子模块，启动时抛出上述错误
• 模块启动失败后所有接口无法访问，请求返回404

顺着错误栈逐层定位：

1. 最底层报错为java.lang.ClassNotFoundException: javax.el.ELManager，即类路径下找不到ELManager类
2. 该类是Hibernate Validator初始化消息插值器时必须依赖的类，缺失直接导致keyValidatorFactory Bean的初始化方法执行失败
3. keyValidatorFactory初始化失败进一步导致keyManagementResource的依赖注入失败，最终Spring Web上下文启动中断，整个Web模块未完成加载，这也是接口返回404的直接原因

本质是依赖版本不匹配：javax.el.ELManager是EL 3.0及以上版本才提供的类，当前运行环境的EL包版本低于3.0，或者类路径下缺失对应版本的EL依赖。从日志中的Tomcat类加载器路径判断，当前使用的是Tomcat 7，其默认自带的el-api版本为2.2，本身就不包含ELManager类，是最高发的触发场景。

• 当前使用的Tomcat具体版本，以及子模块的部署方式（war包部署到外部Tomcat/使用内嵌容器启动）
• 项目中Spring、Hibernate Validator的具体版本号
• 依赖配置文件（pom.xml/build.gradle）中和validation、javax.el相关的依赖片段
• 执行依赖树命令输出的javax.el相关依赖结果：
  • Maven项目执行：mvn dependency:tree -Dincludes=javax.el
  • Gradle项目执行：gradle dependencies | grep javax.el

场景1：使用外部Tomcat 7部署（匹配当前日志的类加载器特征） #

两种方案二选一即可：

• 方案1（推荐）：升级Tomcat版本到8.5及以上，Tomcat 8+默认集成EL 3.0+版本，自带javax.el.ELManager类，无需调整项目代码即可解决问题
• 方案2：不升级Tomcat，在项目依赖中引入EL 3.0的API和实现，注意设置scope为provided，避免和容器自带包冲突：

<!-- Maven依赖示例 -->
<dependency>
    <groupId>javax.el</groupId>
    <artifactId>javax.el-api</artifactId>
    <version>3.0.0</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.glassfish</groupId>
    <artifactId>javax.el</artifactId>
    <version>3.0.0</version>
    <scope>provided</scope>
</dependency>

场景2：存在依赖冲突 #

如果依赖树排查发现存在多个版本的javax.el依赖，低版本被优先级加载，直接在引入低版本EL的依赖项中添加exclusion排除低版本，统一引入3.0+版本即可。

额外注意 #

由于项目整体基于Vert.x开发，需要确认故障子模块是否不必要地引入了Spring Web的ContextLoaderListener配置，如果该子模块不需要启动Spring Web上下文，直接移除web.xml中对应的监听器配置和相关Spring依赖，也可以从根源避免该问题。

内容的提问来源于stack exchange，提问作者Sandeep Negi