What's the difference between two asterisks instead of one asterisk when we refer to paths?
Earlier I was debugging my Spring 3 project. I was trying to add a .swf using
<spring:url var="flashy" value="/resources/images/flash.swf"/>
With my web.xml's ResourceServlet looking like
<servlet-name>Resource Servlet </servlet-name>
<url-pattern>/resources/*</url-pattern>
But unfortunately I was getting this error:
WARN org.springframework.js.resources.ResourceServlet - An attempt to access a protected resource at /images/flash.swf was disallowed.
I found it really strange since all my images in the images folder were accessed but how come my .swf was "protected"?
Afterwards, I decided to change the /resources/* to /resources/** and it finally worked. My question is... why?
This is a path pattern that used in Apache ant, spring team implement it and use it throughout the framework.
For reference, see javadoc of AntPathMatcher (newest javadoc seems to have problem, so I link an old one).
Back to your problem, according to the document, it only have 3 rules:
?matches one character*matches zero or more characters**matches zero or more 'directories' in a path
来源：https://stackoverflow.com/questions/12569308/spring-difference-of-and-with-regards-to-paths