If I have the following entry in struts-config.xml:
...what page will be displayed when the url is "login_page.do"?
I can see what would happen if someone were to submit a form to this URL how it would react (code would be processed and if there was a "failure" it would display the "Failure" case - same with the success case).
But what about just displaying the url which maps to the action (without a post to the action)?
An action will behave the same way regardless of whether it's called from a form submission or as a URL. The execute method will be called and the logic there will determine whether the "success" or "failure" forward is returned.
It's customary to have two different actions for each form: One to prepare for its display and another to process the results of the form submission.