不同版本(2.3,2.4,2.5)的Servlet web.xml 头信息

源网页：http://www.cnblogs.com/modou/articles/1517233.html

Servlet 2.3

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE web-app    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"    "http://java.sun.com/dtd/web-app_2_3.dtd"><web-app>  ...</web-app>

Servlet 2.4

<?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/j2ee"        xmlns:web="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"        xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"        version="2.4">  ...</web-app>

Servlet 2.5

<?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">  ...</web-app>