转载 http://www.cnblogs.com/BuzyAlways/p/5690980.html
servlet版本与tomcat版本对应关系，各版本web.xml头信息写法
The mapping between the specifications and the respective Apache Tomcat versions is:
Servlet Spec JSP Spec EL Spec WebSocket Spec JASPIC Spec Apache Tomcat version Actual release revision Supported Java Versions 4.0 TBD (2.4?) TBD (3.1?) TBD (1.2?) 1.1 9.0.x 9.0.0.M9 (alpha) 8 and later 3.1 2.3 3.0 1.1 1.1 8.5.x 8.5.4 7 and later 3.1 2.3 3.0 1.1 N/A 8.0.x (superseded) 8.0.35 (superseded) 7 and later 3.0 2.2 2.2 1.1 N/A 7.0.x 7.0.70 6 and later (7 and later for WebSocket) 2.5 2.1 2.1 N/A N/A 6.0.x 6.0.45 5 and later 2.4 2.0 N/A N/A N/A 5.5.x (archived) 5.5.36 (archived) 1.4 and later 2.3 1.2 N/A N/A N/A 4.1.x (archived) 4.1.40 (archived) 1.3 and later 2.2 1.1 N/A N/A N/A 3.3.x (archived) 3.3.2 (archived) 1.1 and later web.xml v2.3
1 <?xml version="1.0" encoding="ISO-8859-1"?> 2 <!DOCTYPE web-app PUBLIC "-//Sun Microsystems,Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> 3 4 <web-app5 6 </>web.xml v2.4
xml version="1.0" encoding="UTF-8"web-app id="WebApp_9" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"web.xml v2.5
1 2 3 xmlns="http://java.sun.com/xml/ns/javaee" 4 5 xmlns:xsi 6 7 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 8 9 version="2.5"10 11web.xml v3.0
2 3 web-app 4 ="3.0" 5 xmlns6 xmlns:xsi7 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"8 9 >
