Caused by: java.lang.NoClassDefFoundError: javax/servlet/GenericFilter
这个类没被发现的问题
1、如果用了maven管理jar，到仓库查看对应的路劲下面是否正确打包成功
2、如果打包成功了对应的jar到对应仓库项目还是报这样错误，解压jar包查看目录结构是否正确
3、如何检查jar包的目录结构是否正确？如熟悉jar包的一个应用过程可以通过经验判断，如经验不足可以通过解压正常使用jar对比
4、maven的打包成功了还有可能是多出一部分文件，关于项目配置maven的一些属性，决定项目寻找jar是先本地-私服-远程第三方这么一个先后关系
以上是排查的一个总体过程
还可能有其他比较生僻的现象，下面就是其中一种
如有以下这种错误，其他办法都试过没用，那么可能是你用了springboot 部署在tomcat7 不兼容，换成tomcat 8试试
这个问题既是说可能是一些版本间的兼容问题，可以多搜寻相关问题答案，同时也希望大家能无私分享
ction 10.7.2. Offending class: javax/el/Expression.class
十二月 10, 2020 10:47:28 下午 org.apache.catalina.loader.WebappClassLoaderBase validateJarFile
信息: validateJarFile(/home/app/kuaiyueboche-service/webapps/web-1.0.0.0-SNAPSHOT/WEB-INF/lib/tomcat-embed-core-9.0.35.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
十二月 10, 2020 10:47:28 下午 org.apache.catalina.core.ContainerBase addChildInternal
严重: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: 无法启动组件[StandardEngine[Catalina].StandardHost[localhost].StandardContext[/web-1.0.0.0-SNAPSHOT]]
at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1007)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:983)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:639)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1127)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:2019)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
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:748)
Caused by: java.lang.NoClassDefFoundError: javax/servlet/GenericFilter
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:3258)
at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:1416)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1920)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1795)
at org.apache.tomcat.websocket.server.WsServerContainer.
at org.apache.tomcat.websocket.server.WsSci.init(WsSci.java:137)
at org.apache.tomcat.websocket.server.WsSci.onStartup(WsSci.java:49)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5642)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
... 10 more
Caused by: java.lang.ClassNotFoundException: javax.servlet.GenericFilter
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1951)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1795)
... 22 more
信息: Server startup in 841 ms
信息: validateJarFile(/home/app/kuaiyueboche-service/webapps/ROOT/WEB-INF/lib/tomcat-embed-core-9.0.35.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
十二月 10, 2020 11:30:41 下午 org.apache.catalina.core.ContainerBase addChildInternal
严重: ContainerBase.addChild: start:
org.apache.catalina.LifecycleException: 无法启动组件[StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
at org.apache.catalina.util.LifecycleBase.handleSubClassException(LifecycleBase.java:440)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:198)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1007)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:983)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:639)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1127)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:2019)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NoClassDefFoundError: javax/servlet/GenericFilter
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:756)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:3258)
at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:1416)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1920)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1795)
at org.apache.tomcat.websocket.server.WsServerContainer.
at org.apache.tomcat.websocket.server.WsSci.init(WsSci.java:137)
at org.apache.tomcat.websocket.server.WsSci.onStartup(WsSci.java:49)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5642)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
... 10 more
Caused by: java.lang.ClassNotFoundException: javax.servlet.GenericFilter
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1951)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1795)
... 22 more
十二月 10, 2020 11:30:41 下午 org.apache.catalina.startup.HostConfig deployWAR
严重: 部署 Web 应用程序 archive [/home/app/kuaiyueboche-service/webapps/ROOT.war] 时出错
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: 无法启动组件[StandardEngine[Catalina].StandardHost[localhost].StandardContext[]]
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:1011)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:983)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:639)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:1127)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:2019)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
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:748)