How to bypass defaultAuthenticationMethod

[Peter Schober]

* Vishvjit Khalipe <vishvjit at gmail.com> [2014-02-02 18:48]:
> For all the relying parties we have Kerberos Login Handler as the Default
> Login Handler (defaultAuthenticationMethod). If kerberos authentication
> fails the user is redirected to user password login handler.

Out of curiosity, how do you do this? I thought once a login handler
was chosen you can't just invoke another one (e.g. from a JSP)?
-peter