In my applications I prefer to use Wicket to render all error pages, including my 404 "not found" page. This allows me to reuse a shared page template afforded by Wicket to create my error pages (i.e. by extending a BasePage), rather than using copy and paste to maintain static error page HTML files.
I have been doing this as follows:
Now, so long as I have an appropriate bookmarkable page mounted on the "/error/404" path, the servlet container will render my page whenever a 404 "not found" scenario is encountered.
This works great in Wicket 1.4.x.
However in Wicket 1.5 (RC2 and the latest SNAPSHOT as of this writing), two problems occur:
1. By default, Wicket 1.5 automatically performs a 302 redirect before rendering the error page. This changes the URL from the invalid one (i.e. the one that generated the 404) to the mounted path (/error/404 in this example). This is not the desired behavior for a 404 error page; the original URL requested by the user should be maintained.
2. If I attempt to work around the issue by overriding WebPageRenderer.enableRedirectForStatelessPage() to return false, the problem gets worse. Now the URL doesn't change, which is good. But Wicket gets confused about the depth of the request URL path: it seems to calculate relative URLs based on the mounted path rather than the URL that was requested. This causes all relative resources on the page (e.g. stylesheet references) to be miscalculated and break.
I will attach two quickstarts: one showing this configuration working in 1.4, and another showing the same setup failing as described above in 1.5-RC2.