原创:idea启动项目的是否报错：java.lang.ClassNotFoundException: javax.servlet.ServletContext

Posted 2021-03-04 张氏码农之旅

在Intellij IDEA中默认所有 scope 为 provided 的依赖不会被加入到 classpath；

想想配置正确，怎么不能创建窗容器呢

ava.lang.ClassNotFoundException: javax.servlet.ServletContext

2020-03-21 17:33:17,156 WARN [org.springframework.context.support.ClassPathXmlApplicationContext] - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘mvcContentNegotiationManager‘: Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.web.accept.ContentNegotiationManagerFactoryBean] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘mvcContentNegotiationManager‘: Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.web.accept.ContentNegotiationManagerFactoryBean] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:262)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineConstructorsFromBeanPostProcessors(AbstractAutowireCapableBeanFactory.java:1198)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1123)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:545)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:742)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:868)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:144)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:85)
    at com.ibaiqi.spider.service.TestDeplication.listRecruits(TestDeplication.java:14)
    at com.ibaiqi.spider.service.TestDeplicationAAA.main(TestDeplicationAAA.java:31)
Caused by: java.lang.IllegalStateException: Failed to introspect Class [org.springframework.web.accept.ContentNegotiationManagerFactoryBean] from ClassLoader [sun.misc.Launcher$AppClassLoader@18b4aac2]
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:659)
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:556)
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:541)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.determineCandidateConstructors(AutowiredAnnotationBeanPostProcessor.java:245)
    ... 15 more
Caused by: java.lang.NoClassDefFoundError: javax/servlet/ServletContext
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.getDeclaredMethods(Class.java:1975)
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:641)
    ... 18 more
Caused by: java.lang.ClassNotFoundException: javax.servlet.ServletContext
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:338)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 22 more
Disconnected from the target VM, address: ‘127.0.0.1:52084‘, transport: ‘socket‘

Process finished with exit code 1

 

异常详情：

这是我遇到的异常控制台截图，如下：

异常解释：

在Intellij IDEA中默认所有 scope 为 provided 的依赖不会被加入到 classpath；

所以在编译器启动 spring boot 项目时，会由于某些依赖加载不到而报 javax.servlet.ServletContext 异常。
解决办法：

方法一、 修改【IDEA】- Edit Configurations 的配置项：

步骤1：菜单栏 -> Run -> Edit Configurations

步骤2：Run/Debug Configurations -> Application -> Configuration -> 勾选：include dependencies with "Provided" scope

 

方法二、修改【pom.xml 】文件中的配置：

步骤1：找到图片中的 “spring-boot-starter-tomcat” 标签，有三种方式可以尝试；

    将 <scope>provided</scope> 注释掉 ；
    <scope> 标签内容provided改成compile：<scope>compile</scope> ；
    <scope>标签内写明具体版本，如：<version>1.5.2.RELEASE</version>；

步骤2：这是关于容器的配置，需要把容器tomcat重新加载一下。
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原文链接：https://blog.csdn.net/weixin_44259720/article/details/94602764