web.xml不同的头文件

《转自：http://blog.csdn.net/qq_16313365/article/details/53783288》

1. Servlet 3.1

Java EE 7 XML schema，命名空间是 http://xmlns.jcp.org/xml/ns/javaee/

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
5. http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
6. version="3.1">
7. </web-app>

2. Servlet 3.0

JavaEE 6 XML schema，命名空间是 http://Java.sun.com/xml/ns/javaee

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app xmlns="http://java.sun.com/xml/ns/javaee"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
5. http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
6. version="3.0">
7. </web-app>

3. Servlet 2.5

Java EE 5 XML schema，命名空间是 http://java.sun.com/xml/ns/javaee

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app xmlns="http://java.sun.com/xml/ns/javaee"
3. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4. xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
5. http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
6. version="2.5">
7. </web-app>

4. Servlet 2.4

Java EE 1.4 XML schema, 命名空间是 http://java.sun.com/xml/ns/j2ee

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app 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
5. http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
6. version="2.4">
7. </web-app>

5. Servlet 2.3

Java EE 1.3 DTDs schema，这个版本的web.xml文件太老了，强烈建议升级

1. <!DOCTYPE web-app PUBLIC
2. "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
3. "http://java.sun.com/dtd/web-app_2_3.dtd" >
4. <web-app>
5. <display-name>Servlet 2.3 Web Application</display-name>
6. </web-app>