Consistent warn logging for handled exceptions [SPR-17178]

[spring-projects-issues]

Ran Cohen opened SPR-17178 and commented

I had a controller, and a field in the controller marked as Long. I tried using a url with the field being 0.88, and nothing happend.

After extensive debug, I found a Bind exception, and the reason I thought nothing happend is that the class RequestMappingHandlerAdapter in the method invokeHandlerMethod has a try... finally, no catch.

I wasted a few hours trying to figure out what happend.

Please fix it.

---

Affects: 4.3.14

Issue Links:

• ExceptionHandlerExceptionResolver started to log on WARN level [SPR-17383] #21916 ExceptionHandlerExceptionResolver started to log on WARN level
• AbstractHandlerExceptionResolver logs handled exceptions at WARN [SPR-17399] #21932 AbstractHandlerExceptionResolver logs handled exceptions at WARN

Referenced from: commits 8e980d9, 41e6aa6, a409233, bf7fa39, 04141de, 6ea3441, de453ac

Backported to: 4.3.19

[spring-projects-issues]

Juergen Hoeller commented

This is intentional: Exceptions are being propagated to the DispatcherServlet level from there, to be processed by a HandlerExceptionResolver or ultimately propagated to the Servlet container (similar to a regular servlet throwing an exception). I wonder why your bind exception didn't show up in those places?

[spring-projects-issues]

Ran Cohen commented

I don't know if that was the problem, but my log level was info, not debug, so I didn't see the exception. 

Exceptions like this should at least be in a warning log, not debug I think.

[spring-projects-issues]

Juergen Hoeller commented

Rossen Stoyanchev, what's your take on this? Some of the cases in DefaultHandlerExceptionResolver indeed only lead to a particular HTTP response but not easily noticeable logging on the server side... We have a few warn log cases there already, do we need to cover further ground with those?

[spring-projects-issues]

Rossen Stoyanchev commented

I'd expect a response with status 400? In other words the exception was probably handled. That said we do need to ensure consistent warn log messages in DefaultHandlerExceptionResolver..