Spring Security 3 with a login form for some URLs and an error page for others

I'm using Spring Security 3 to protect access to a Spring-based Java Web application. The security mechanism is all configured through a standard Spring Security bean definition file, using the "security" schema. By default the user can access any URL and those that require a login are listed in the “http” element of the Spring configuration file. The system is configured so that a user who has not performed a login will 开发者_运维百科be redirected to a login form before they can access such a URL.

The problem that I have is that certain URLs in the system are intended for programmatic access and return XML rather than HTML. For such URLs I need to be able to return a “user not logged in” XML instead of forcing a redirect to a login form. How can I reconfigure my “http” element (and its associated elements in the configuration file) to allow me to have one set of controlled URLs that will redirect to a login form when the user isn't logged in and another set that will return an error?

Cheers, Adam.

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Maybe an authentication filter helps you. Inside the doFilter() method of Spring's AbstractAuthenticationProcessingFilter you could check whether a XML file is requested. If yes, you interrupt the chain and return an error XML file if there's no active user session. See here for more details:

http://mark.koli.ch/2010/07/spring-3-and-spring-security-setting-your-own-custom-j-spring-security-check-filter-processes-url.html