Web-app 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 2.4<web-app id=" Webapp_9 "version=" 2.4 "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" > Web-app 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" > JDK version 1.5 + Web-app 3.0<web-app
version= "3.0"
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" > JDK version 1.6 and above, start support Jsp-config configuration Web-app 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/javaee/web-app_3_1.xsd"
version= "3.1" > JDK version 1.7 or above
Constraints for each version of Web. xml
