注：Intellij idea使用Maven搭建web專案啟動報找不到類，而maven的pom.xml都已引用，問題就是在於沒在WEB-INF下新建lib資料夾

在IDEA開發23體驗網的SpringMVC專案時，會出現一些錯誤，其中比較典型之一的就是除錯SpringMvc中，出現：java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener錯誤的解決辦法：

有時，那麼使用idea開發SpringMvc發現除錯時，在Console面板中就會報紅色的錯誤，出現以下錯誤：

12-Mar-2018 12:08:02.345 嚴重 [RMI TCP Connection(2)-127.0.0.1] org.apache.catalina.core.StandardContext.listenerStart 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:1285) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119) at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:520) at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:501) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:118) at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4649) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5189) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:724) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:700) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:734) at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1702) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:482) at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:431) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:300) at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819) at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801) at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468) at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76) at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309) at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1401) at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:324) at sun.rmi.transport.Transport$1.run(Transport.java:200) at sun.rmi.transport.Transport$1.run(Transport.java:197) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.Transport.serviceCall(Transport.java:196) at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683) at java.security.AccessController.doPrivileged(Native Method) at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at java.lang.Thread.run(Thread.java:745)

那麼這個時候我們就可以在IDEA中這樣設定，就可以解決java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener錯誤的解決辦法​。

在IDEA中點選File > Project Structure > Artifacts > 在右側Output Layout右擊專案名，選擇Put into Output Root。

​執行後，在WEB-INF在增加了lib目錄，裡面是專案引用的jar包，點選OK。​

要想到能夠完全的消除SpringMvc的錯誤，千萬別忘了要重啟那隻貓咪——Tomcat，就可以解決SpringMvc的這個錯誤了。

--------------------- 本文來自 du_23tiyanwang 的CSDN 部落格 ，全文地址請點選：https://blog.csdn.net/du_23tiyanwang/article/details/80654313?utm_source=copy