在使用maven或者gradle进行构建项目的时候，有时会出现异常：ClassNotFoundException。具体异常如下：

严重: Error configuring application listener of class ch.qos.logback.ext.spring.web.LogbackConfigListener
java.lang.ClassNotFoundException: ch.qos.logback.ext.spring.web.LogbackConfigListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1858)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1701)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:504)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:486)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4984)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5584)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

org.apache.catalina.core.StandardContext listenerStart
严重: Error configuring application listener of class org.springframework.web.util.IntrospectorCleanupListener
java.lang.ClassNotFoundException: org.springframework.web.util.IntrospectorCleanupListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1858)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1701)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:504)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:486)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4984)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5584)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

下午 org.apache.catalina.core.StandardContext listenerStart
严重: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1858)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1701)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:504)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:486)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4984)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5584)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

org.apache.catalina.core.StandardContext listenerStart
严重: Error configuring application listener of class org.springframework.web.context.request.RequestContextListener
java.lang.ClassNotFoundException: org.springframework.web.context.request.RequestContextListener
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1858)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1701)
    at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:504)
    at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:486)
    at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4984)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5584)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:899)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:875)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1260)
    at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:2002)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:745)

以上异常所报缺失的class主要是你项目加载的时候没有jar包，大家应该先检查下自己项目中的gradle或者maven的jar包是否都齐了。

如果没有看到maven或者gradle导入的jar包，那就进行如下操作：

我这边是使用的gradle进行的，maven也是类似的，以上就能将jar包进行相关的添加，解决以上的异常。