一、Tomcat启动报错：
有时候我们会避免项目重名，在导入项目时会修改项目名称。修改项目名称后启动该项目至tomcat，报错：java.lang.IllegalArgumentException: Can't convert argument: null二、问题分析：因为MyEclipse在修改项目名时候，自动更新部署了web.xml文件并且重新生成了xml文件的头部声明. 会将标签修改为 <javaee:param-name>这样的类型。三、解决问题：修改项目的web.xml，将其中带有javaee:的标签中的javaee:删掉即可，也可以直接Ctrl+F将javaee:直接全部替换为空。四、报错信息如下：java.lang.IllegalArgumentException: Can't convert argument: nullat org.apache.tomcat.util.IntrospectionUtils.convert(IntrospectionUtils.java:999)at org.apache.tomcat.util.digester.CallMethodRule.end(CallMethodRule.java:523)at org.apache.tomcat.util.digester.Rule.end(Rule.java:229)at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1140)at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(Unknown Source)at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1644)at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:365)at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1066)at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:261)at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)at org.apache.catalina.core.StandardContext.start(StandardContext.java:4252)at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:627)at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:553)at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:488)at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1149)at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)at org.apache.catalina.core.StandardService.start(StandardService.java:516)at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)at org.apache.catalina.startup.Catalina.start(Catalina.java:578)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)at java.lang.reflect.Method.invoke(Unknown Source)at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)问题是由于在Eclipse下重构JEE项目名时，Eclipse自动更新了部署文件web.xml,重新生成了xml文件的头部声明，新增加了javaee的命名空间：如下<servlet> <javaee:display-name>MessageBrokerServlet</javaee:display-name> <servlet-name>MessageBrokerServlet</servlet-name> <servlet-class>flex.messaging.MessageBrokerServlet</servlet-class> <init-param> <javaee:param-name>services.configuration.file</javaee:param-name> <javaee:param-value>/WEB-INF/flex/services-config.xml</javaee:param-value> </init-param> <load-on-startup>1</load-on-startup></servlet>将标签 <javaee:param-name> 中的javaee:删掉就完美解决问题，直接Ctrl+F将javaee:直接全部替换为空。 --------------------- 本文来自 Lemyou 的CSDN 博客 ，全文地址请点击：https://blog.csdn.net/Lemyou/article/details/80373024?utm_source=copy