3.0
<?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/javaee" xsi:schemalocation= "Http://java.sun.com/xml/ns/javaee/http Java.sun.com/xml/ns/javaee/web-app_3_0.xsd "id=" webapp_id "version=" 3.0 "></web-app>
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>
2.4
<?xml version= "1.0" encoding= "UTF-8"? ><web-app xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance" xmln s= "Http://java.sun.com/xml/ns/j2ee" xmlns:web= "Http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" Xsi:schemalo cation= "Http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version= "2.4" ></ Web-app>
2.3
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>
Web. XML 2.3/2.4/2.5/3.0 Head