web.xml v2.3
- <?xml version="1.0" encoding="ISO-8859-1"?>  
- <!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 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"   
-     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>  
 
 
web.xml v2.5
 
- <?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>  
 
 
web.xml v3.0
 
- <?xml version="1.0" encoding="UTF-8"?>  
-    
- <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">  
-    
- </web-app>  
 
 
 
web-fragment.xml
 
- <web-fragment 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-fragment_3_0.xsd" version="3.0">  
-    
- </web-fragment>  
 
 
Appweb写法
原文:http://www.cnblogs.com/flycatnet/p/5917427.html