Spring MVC (3.0) considers URLs with and without trailing slashes as the same URL.
For example:
http://www.example.org/data/something = http:
Not sure if spring 3.0 had this, but spring 3.1 RequestMappingHandlerMapping allows you to set a "useTrailingSlashMatch" property. By default it is true.
I think switching it to false would solve your issue, however it would affect ALL mappings handled by RequestMappingHandlerMapping across your application... so you may have a fair amount of regression to do.