Dropwizard custom exception mapper not working

Question

I have some strange problem with dropwizard exception handling. I wrote custom exception mapper very similar to this http://gary-rowe.com/agilestack/2012/10/23/how-to-implement-a-runtimeexceptionmapper-for-dropwizard/ . For status 400 my code is

   if (webAppException.getResponse().getStatus() == 400) {  
              return Response
                .status(Response.Status.BAD_REQUEST)
                .entity("Request sent to server is bad.")
                .build();
            }

In code when i use throw new WebApplicationException(400) it works great, mapper catches exception and return response with a message but when i modify code to look like this

String msg=webAppException.getResponse().getEntity().toString();
              return Response
                .status(Response.Status.BAD_REQUEST)
                .entity("Request sent to server is bad."+msg)
                .build();

and in code use something like thisthrow new WebApplicationException(Response.status(400).entity("hello!").build()) it returns just "hello!". Mapper does not catch this exception at all. It only catch when i provide just status code. I removed all dropwizard mappers using instructions from this link http://thoughtspark.org/2013/02/25/dropwizard-and-jersey-exceptionmappers/ but it still does not catch this exception. It is not because of above modification in mapper because it does not call "toResponse" method at all. So, my question is why it behave like this. I could leave like this it is "good enough", but i want to know why it wont work and it would be better if it works with mapper so i can handle exceptions easier. Thanks in advance

same problem for me as of the current date... documentation and github code samples show nothing useful for me — dtc
This post is quite old but we're experiencing the same issue now. We're using Dropwizard 1.0.9. Anyone knows a solution or why this happens? Actually, we've seen that the WebApplicationException is intercepted by the ExceptionMapper if the Response entity is null, e.g. throw new WebApplicationException(Response.status(400).entity(null).build()); — Ferran Maylinch

Ferran Maylinch Ferran Maylinch · Accepted Answer · 2019-04-16T10:57:07

By debugging we found that this behaviour is done in org.glassfish.jersey.server.ServerRuntime (mapException method).

This method checks if (throwable instanceof WebApplicationException) and then if (waeResponse.hasEntity()), and in that case it just returns the waeResponse without calling any exception mapper.

So, when you throw a WebApplicationException with a response that contains an entity, it won't reach your exception mapper.

Dropwizard custom exception mapper not working

1 Answers