How to log exception of Unable to process JSON in dropwizard

[Rohit Verma]

Hi All,

Is there a way to find out which field of my pojo object caused Unable to process JSON error, or is there a way to log jackson exception which cause this error 

[Steve Kradel]

Yes: suppress the default exception mapper, and provide one like this (in this case we tell the client what it did wrong, but you could log instead or in addition to):

import java.util.LinkedHashMap;

 

import java.util.Map;


 

import javax.ws.rs.core.MediaType;

import javax.ws.rs.core.Response;

import javax.ws.rs.core.Response.Status;

import javax.ws.rs.ext.ExceptionMapper;

import javax.ws.rs.ext.Provider;


 

import com.fasterxml.jackson.core.JsonProcessingException;


 

@Provider

public class JsonInformativeExceptionMapper implements ExceptionMapper<JsonProcessingException> {


 

 @Override

 public Response toResponse(JsonProcessingException exception) {

 

 Map<String,Object> entity = new LinkedHashMap<>();

 entity.put("code", 400);

 

 {

 String message = exception.getOriginalMessage();

 if (message != null) {

 int pos = message.indexOf('\n');

 if (pos == -1) {

 pos = message.indexOf(" at [Source");

 }

 if (pos > 0) {

 message = message.substring(0, pos);

 }

 entity.put("message", message);

 }

 }

 

 if (exception.getLocation() != null) {

 entity.put("location", String.format("line %d, column %d",  

 exception.getLocation().getLineNr(),  

 exception.getLocation().getColumnNr()));

 }

 

 return Response.status(Status.BAD_REQUEST)

 .type(MediaType.APPLICATION_JSON_TYPE)

 .entity(entity)

 .build();

 }

}

[Chris Stromberger]

I added this in the Application class to override the existing JsonProcessingExceptionMapper, did the trick for my application. The true parameter is for "showDetails".

jersey.register(new JsonProcessingExceptionMapper(true));