[jetty-users] Custom error handler & use with Proxy Servlet

[Mark Payne <mark.payne@xxxxxxxxxxx>]

I have been using Jetty 7.1.6 embedded to host a couple of servlets I 
have written myself, as well as a servlet that I extended from the jetty 
ProxyServlet. I use the extended ProxyServlet so that I can call some 
custom code when the HttpExchange onExpire() or onException() methods 
get called. The general arrangement of things is as follows:

...

server = new Server(port);

ServletContextHandler context = new ServletContextHandler(
	ServletContextHandler.SESSIONS);
context.setErrorHandler(new CustomErrorHandler(this));
context.setContextPath("/");
server.setHandler(context);

// First servlet
context.addServlet(new ServletHolder(new CustomServlet1(), "/context1/*");

// Second servlet
context.addServlet(new ServletHolder(new CustomServlet2(), "/context2/*");

// Forward any requests that can't be handled by CustomServlet1
//  or CustomServlet2 to another server that can handle them
context.addServlet(new ServletHolder(new CustomProxy.Transparent(
               "/", backEndServerHost, backEndServerPort)), "/");

...

The class that creates & starts the Jetty server needs to keep track of 
whether there are any problems with the servlets i.e. if for some reason 
they respond with status 500 (Internal server error). To do this I 
create a custom error handler that I add to the ServletContextHandler 
using setErrorHandler() as shown above.

Now, when I do response.sendError() in my custom servlets this gets 
picked up by the custom error handler which checks the status code and 
acts as I want. But when I call response.sendError() as a result of 
onExpire() or onException() in the proxy servlet the custom error 
handler isn't called. I still get a formatted HTML page with some 
information about the exception, so SOME error handling code gets 
called, but not mine. Can anyone explain why not?

Thanks,

Mark