org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[]

运行servlet程序报错：

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/WebTest]]

Caused by: java.lang.IllegalArgumentException: Invalid <url-pattern> in servlet mapping

原因：

web.xml里面的url-pattern配置不正确，可能是少了个斜杠  /

解决方案：

<url-pattern>redirect<url-pattern>

改为<url-pattern>/redirect<url-pattern>