One would think the answer to this question is all over the web. But honestly, I can't find any good answers.
I want to customize (or redirect) the 400-500 errors running on my apache tomcat server.
Oddly, the current 404 message is blank.. doesn't even say 404??
The source of the page is: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=windows-1252"></HEAD> <BODY></BODY></HTML>
I've edited the web.xml file here at the very bottom and restarted the server: C:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\web.xml
Tomcat has, in effect, a "shadow" webapp that lies underneath the actual webapps. It's where requests that cannot be processed using the logic that's in the webapp go.
The most obvious case is when you submit a URL that doesn't map to any of the servlets defined in a webapp's web.xml file. For example, a JSP or image request.
When the URL doesn't fit the app's URL pattern list, it gets sent to this "shadow" app's default servlet, which provides the default action - locating a compiled JSP (and, if necessary compiling it) and invoking its generated servlet code, or for non-code files and directories, copying/listing the contents of the file or directory whose resource location corresponds to the path provided in the URL.
If I tried, I could probably find a way to do what you're asking, but I don't recommend it. The default actions for Tomcat really shouldn't be customized, or the essential portability of web applications becomes compromised. Ideally, a J2EE/JEE web app is self-contained and will operate the same way on any copy of Tomcat in the world. And will require minimal changes to run on any other brand of J2EE/JEE-compliant web application server, such as JBoss.
An IDE is no substitute for an Intelligent Developer.