servlet-mapping的三种通用路径配置方式（Filter-mapping也一样）

在配置web.xml的servlet-mapping 的 url-pattern 碰到问题, 上网查, 查到servelt2_2-spec.pdf才得到答案. 

结论: 
•  '/XXX/*' 
•  '*.html' 
•  '/' 
•  其他都是精确映射 
      例: '/XXX/Y*.html' 只能映射/XXX/Y*.html 的URL请求. 
      例: '/XXX' 只可以映射/XXX的URL请求. 

引用

10.2 Specification of Mappings 
In the web application deployment descriptor, the following syntax is used to define mappings: 
• A string beginning with a '/' character and ending with a '/*' postfix is used as a path 
mapping. 
• A string beginning with a '*.' prefix is used as an extension mapping. 
• All other strings are used as exact matches only 
• A string containing only the '/' character indicates that servlet specified by the mapping becomes the "default" servlet of the application. 

翻译如下: 
10.2 映射规则说明 
在web应用的部署描述中(web.xml)中, 以下语法结构用于定义映射: 
• 以'/'开头 并以'/*'结尾的字符串用于做路径的映射. 
• 以'*.'开头 用于做扩展的映射. 
• 其他的所有字符串都是只做精确映射. 
• 一个只是'/'的字符串 将当前这个servlet明确为应用的默认servlet. 


参考: 
可以下载servelt2_2-spec.pdf 
http://java.sun.com/products/servlet/2.2/ 

对于web.xml 元素的具体描述 
http://e-docs.bea.com/wls/docs61/webapp/web_xml.html#1017231

 

servlet-mapping Element

The servlet-mapping element defines a mapping between a servlet and a URL pattern.

The following table describes the elements you can define within a servlet-mapping element.

Element	Required/ Optional	Description
	Required	The name of the servlet to which you are mapping a URL pattern. This name corresponds to the name you assigned a servlet in a  declaration tag.
	Required	Describes a pattern used to resolve URLs. The portion of the URL after the http://host:port + WebAppName is compared to the  by WebLogic Server. If the patterns match, the servlet mapped in this element will be called. Example patterns: /soda/grape/* /foo/*  /contents *.foo The URL must follow the rules specified in Section 10 of the Servlet 2.2 Specification. For additional examples of servlet mapping, see Servlet Mapping.