关于web.xml不同版本之间的区别

WEB.XML的标签配置与serlet版本有关

一、Servlet 2.3 

 <!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 >
      < display-name >Servlet 2.3 Web Application</ display-name >
</ web-app >

二、Servlet 2.4 

  <web-app xmlns="http://java.sun.com/xml/ns/j2ee"

          xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
          http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
          version = "2.4" >

              < display-name >Servlet 2.4 Web Application</ display-name >
</ web-app >

三、Servlet 2.5

< 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 >Servlet 2.5 Web Application</ display-name >
</ web-app >

四、Servlet 3.0 

 <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_3_0.xsd"
          version = "3.0" >

              < display-name >Servlet 3.0 Web Application</ display-name >
</ web-app >

五、Servlet 3.1

 <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"

         xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation = "http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/java          ee/web-app_3_1.xsd"
         version = "3.1" >

         < display-name >Servlet 3.1 Web Application</ display-name >
</ web-app >