tomcat部署时出错

Caused by: java.lang.IllegalArgumentException: Invalid <url-pattern> DownsetupServlet in servlet mapping
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3324)
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3299)
at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1438)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1357)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5416)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 10 more

此问题一般是由于web.xml出错

经过检查发现少写了斜杠/