新安装的Tomcat使用startup.bat报错,访问localhost 404

18-Jun-2020 22:09:16.247 信息 [localhost-startStop-1] org.apache.catalina.startup.HostConfig.deployDirectory 把web 应用程序部署到目录 [D:Tomcat8apache-tomcat-8.5.56webappsexamples] 18-Jun-2020 22:09:16.270 严重 [localhost-startStop-1] org.apache.catalina.core.ContainerBase.addChildInternal ContainerBase.addChild: start: org.apache.catalina.LifecycleException: 无法启动组件[StandardEngine[Catalina].StandardHost[localhost].StandardContext[/examples]] 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:743) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:719) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:705) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1125) at org.apache.catalina.startup.HostConfigDeployDirectory.run(HostConfig.java:1858) at java.util.concurrent.ExecutorsRunnableAdapter.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/ServletContainerInitializer at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:763) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:468) at java.net.URLClassLoader.access$100(URLClassLoader.java:74) at java.net.URLClassLoader$1.run(URLClassLoader.java:369) at java.net.URLClassLoader$1.run(URLClassLoader.java:363) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:362) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1277) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1180) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:348) at org.apache.catalina.startup.WebappServiceLoader.loadServices(WebappServiceLoader.java:232) at org.apache.catalina.startup.WebappServiceLoader.load(WebappServiceLoader.java:203) at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1635) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1136) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:776) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:299) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5053) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) … 10 more Caused by: java.lang.ClassNotFoundException: javax.servlet.ServletContainerInitializer at java.net.URLClassLoader.findClass(URLClassLoader.java:382) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) … 34 more

我们看到Cause by 就是servlet这个jar包的问题,在Tomcat的lib里找到servlet这个包,把他放到你JAVA_HOME的jdk -> lib -> ext里,然后重新启动就好了