Spring 3.1.RC1 and PATH_WITHIN_HANDLER_MAPPING_ATT

问题:

Posted in spring forum with no response.

I have the following code snippet (from here), which is part of my pet project.

@Controller
@RequestMapping("/browse")
public class MediaBrowser {
   ...

    @RequestMapping("/**")
    public final ModelAndView listContents(final HttpServletRequest request) {

        String folder = (String) request.getAttribute(
                HandlerMapping.PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE);
                ...
    }

I access the following url:

http://localhost:8080/myapp/browse

• In spring 3.0.6.RELEASE, I got the folder variable as null, which is the expected value.
• In spring 3.1.RC1, the folder variable is /browse.

Is this a bug or has something changed in spring-3.1?

回答1:

As skaffman said, you probably shouldn't use PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE. Take a look at How to match a Spring @RequestMapping having a @pathVariable containing "/"? for an example of using AntPathMatcher to accomplish what you are trying

回答2:

This looks very much like an internal implementation detail of the framework, one that you should not be relying on.

The javadoc for PATH_WITHIN_HANDLER_MAPPING_ATTRIBUTE says:

Note: This attribute is not required to be supported by all HandlerMapping implementations. URL-based HandlerMappings will typically support it, but handlers should not necessarily expect this request attribute to be present in all scenarios.

I wouldn't be surprised if the behaviour changed slightly between 3.0 and 3.1.