web.xml文件中的url-pattern是如何进行的？

在上一片blog中最后留下了这么一个问题。下面开始来解决。参考：

http://www2.roguewave.com/support/docs/leif/leif/html/bobcatug/7-3.html

http://foxty.javaeye.com/blog/39332

http://blog.chinaunix.net/u2/86974/showart_1776019.html

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.

For example, a web.xml file for the examples context on the server at example.com matches the pattern in <url-pattern>/status/*</url-pattern> as follows:

http://example.com/examples/status/synopsis	Matches
http://example.com/examples/status/complete?date=today	Matches
http://example.com/examples/status	Matches
http://example.com/examples/server/status	Does not match

A context located at the path /examples on the server at example.com matches the pattern in <url-pattern>*.map</url-pattern>

as follows:

http://example.com/examples/US/Oregon/Portland.map	Matches
http://example.com/examples/US/Washington/Seattle.map	Matches
http://example.com/examples/Paris.France.map	Matches
http://example.com/examples/US/Oregon/Portland.MAP	Does not match, the extension is uppercase
http://example.com/examples/interface/description/mail.mapi	Does not match, the extension is mapi rather than map