初始的web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"version="2.5"><display-name>projectname</display-name><!-- 欢迎页 --><welcome-file-list><welcome-file>index.html</welcome-file><welcome-file>index.jsp</welcome-file></welcome-file-list></web-app>