java.lang.IllegalArgumentException: Invalid <url-pattern> _Web前端

java.lang.IllegalArgumentException: Invalid <url-pattern>
Tomcat启动报错：

java.lang.IllegalArgumentException: Invalid <url-pattern>
严重: End event threw exception java.lang.reflect.InvocationTargetException 

at sun.reflect.GeneratedMethodAccessor18.invoke(Unknown Source)

……

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

 

严重: Parse error in application web.xml file at jndi:/localhost/drp3.6/WEB-INF/web.xml

java.lang.IllegalArgumentException: Invalid <url-pattern> servlet/item/ShowAddItemServlet in servlet mapping

at org.apache.tomcat.util.digester.Digester.createSAXException(Digester.java:2806)

……

错误原因：非法的<url-pattern>表达式

应将<url-pattern> servlet/item/ShowAddItemServlet

改为：<url-pattern> /servlet/item/ShowAddItemServlet

即如果有虚拟的文件夹，那么文件夹前要加斜杠“/”

<servlet-mapping>
  <servlet-name>spring</servlet-name>
  <url-pattern>*.do</url-pattern>//这里不要前面的 '/'
</servlet-mapping>