web.xml部署描述文件定义

Servlet 2.3之前的版本使用DTD作为部署描述文件的定义，其web.xml的格式为如下所示：

 

  <?xml version="1.0" encoding="IS0-8859-1"?>
　　<!DOCTYPE web-app
　　PUBLIC "-//sunMicrosystems,Inc.//DTD WebApplication 2.3f//EN"
　　"http://java.sun.com/j2ee/dtds/web-app_2.3.dtd">
　　<web-app>
　　.......
　　</web-app>

 

 

Servlet 2.4版首次使用XML Schema定义作为部署描述文件，这样Web容器更容易校验web.xml语法。同时XML Schema提供了更好的扩充性，其web.xml中的格式如下所示：

 

　　<?xml version="1.0" encoding="UTF-8"?>
　　<web-app version="2.4" xmlns=http://java.sun.com/xml/ns/j2ee
　　xmlns:workflow=http://www.workflow.com
　　xmins: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">
　　.........
　　</web-app>

 

 

XML Schema Definition: tomcat6.0\lib\servlet-api.jar javax\servlet\resources\web-app_2_4.xsd

部分说明:

    <xsd:annotation>
    <xsd:documentation>
      <![CDATA[

	This is the XML Schema for the Servlet 2.4 deployment descriptor.
	The deployment descriptor must be named "WEB-INF/web.xml" in the
	web application's war file.  All Servlet deployment descriptors
	must indicate the web application schema by using the J2EE
	namespace:

	http://java.sun.com/xml/ns/j2ee

	and by indicating the version of the schema by
	using the version element as shown below:

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

	The instance documents may indicate the published version of
	the schema using the xsi:schemaLocation attribute for J2EE
	namespace with the following location:

	http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd

	]]>
    </xsd:documentation>
  </xsd:annotation>

   

 

最新的Servlet 2.5版XML Schema web.xml中的格式:

    <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/j2ee
　　http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd" 
      version="2.5"> 
      ... 
    </web-app>