Fetching protected URL in tomcat

[Per Steffensen]

Hi

Using (JBoss/)Tomcat.

I am using declarative protection to protect some of the pages on my
site. Like this in web.xml:
<security-constraint>
<web-resource-collection>
<web-resource-name>X users</web-resource-name>
<description>X users</description>
<url-pattern>*.do</url-pattern>
<http-method>GET</http-method>
<http-method>POST</http-method>
</web-resource-collection>
<auth-constraint>
<description>X users</description>
<role-name>user</role-name>
</auth-constraint>
</security-constraint>

I use a login.jsp to login. It is set up in web.xml:
<login-config>
<auth-method>FORM</auth-method>
<form-login-config>
<form-login-page>login.jsp</form-login-page>
<form-error-page>login.jsp</form-error-page>
</form-login-config>
</login-config>

It works fine. When I try to go to a *.do page without being locked
in, I am sent to login.jsp for login.

My problem is:
How do I, in login.jsp code, fetch information about the URL the user
was trying to go to, when we was sent to login.jsp.
Using WebLogic you can read the "j_target_url" attribute from session
scope, but how do you do it on (JBoss/)Tomcat??

Thanx