Error Page Recipe

Serving Tapestry Pages as Servlet Error Pages

Do you want to dress up your site and use a snazzy Tapestry page instead of the default 404 error page? Using modern servlet containers, this is a snap!

Simply upgrade your application web.xml to the 2.4 version, and make a couple of changes:

web.xml

Tapestry's filter must be marked as a handler for both standard requests and errors. That's accomplished with the <dispatcher> elements inside the <filter-mapping> section.

You must then map error codes to Tapestry URLs. In this case, the 404 error is send to the /error404 resource, which is really the "Error404" Tapestry page.

We'll create a simple Error404 page, one that displays a message and (in development mode) displays the details about the incoming request.

Error404.tml

The page simply makes the request and productionMode properties available:

Error404.java

The end-result, in when not in production mode, looks like this:

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An issue with an application that has a root Index page is that any invalid path, which would normally generate a 404 error, is instead routed to the Index page (because the invalid path looks like page's activation context). See Issue TAP5-2070.