JavaEE tomcat10踩坑记录

1. 工具介绍

1. tomcat: stable 10.0.6
2. IDEA 2021.1.1
3. maven: stable 3.8.1

2. 过程描述

1. 使用idea直接创建项目选用java enterprise

2. 项目自动生成pom文件, 引入servlet-api的依赖

   1.  <dependency>
           <groupId>javax.servlet</groupId>
           <artifactId>javax.servlet-api</artifactId>
           <version>4.0.1</version>
           <scope>provided</scope>

3. 编写项目没有问题, 运行项目以后静态资源没问题,servlet报错

       HTTP状态 500 - 内部服务器错误
   
       ------
   
       **类型** 异常报告
   
       **消息** 实例化Servlet类[com.xrluo.ee.HelloServlet]异常
   
       **描述** 服务器遇到一个意外的情况，阻止它完成请求。
   
       **例外情况**
   
       jakarta.servlet.ServletException: 实例化Servlet类[com.xrluo.ee.HelloServlet]异常
           org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
           org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
           org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
           org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:353)
           org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
           org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
           org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870)
           org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1696)
           org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
           java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
           java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
           org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
           java.lang.Thread.run(Thread.java:748)
       **根本原因。**
       java.lang.NoClassDefFoundError: javax/servlet/http/HttpServlet
           java.lang.ClassLoader.defineClass1(Native Method)
           java.lang.ClassLoader.defineClass(ClassLoader.java:763)
           java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
           org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2470)
           org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:866)
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1370)
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1224)
           org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
           org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
           org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
           org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:353)
           org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
           org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
           org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870)
           org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1696)
           org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
           java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
           java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
           org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
           java.lang.Thread.run(Thread.java:748)
   
       **根本原因。**
       java.lang.ClassNotFoundException: javax.servlet.http.HttpServlet
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1401)
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1224)
           java.lang.ClassLoader.defineClass1(Native Method)
           java.lang.ClassLoader.defineClass(ClassLoader.java:763)
           java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
           org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2470)
           org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:866)
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1370)
           org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1224)
           org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:543)
           org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
           org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690)
           org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:353)
           org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374)
           org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
           org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:870)
           org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1696)
           org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
           java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
           java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
           org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
           java.lang.Thread.run(Thread.java:748)

3. 解决问题

目前迷茫中,理论来说maven会下载项目所需要的依赖, 为什么还会与tomcat里面的httpServlet有关系??

同样遇到坑的小伙伴的文章：
Tomcat10的坑

欢迎大佬解答