*
参考地址
http://www.cnblogs.com/rollenholt/articles/2790173.html
我的问题与他一样,从旧项目中复制了一个web.xml到新项目,version都还是2.4,后来改为下面即可(tomcat7)
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>222</display-name>
*