title: JsonParseExceptionMapper not called by Jersey
body: <p>I use Jersey and Jackson to implement RESTful services provided by my server. Data is exchanged between the client and server as JSON documents. Jackson does the mapping between the JSON documents and the POJOs. This works well. </p>
  
  <p>But I ran into one issue. When calling a service with a malformed JSON document, the server returns with an 500 error. I would expect a 400 BAD-Request error instead. Some searching in the Jersey docs showed me that ExceptionMappers can be used to archive this behavior. I also found out that Jackson already has a implementation a JsonParseExceptionMapper but it never gets called. </p>
  
  <p>Do I have to register the mapper and if so how can I do this outside of the source code.?</p>