How to Produce ErrorMessage in JSON Response - json

Question

I have Implemented a Restful Webservice which produces JSON as my response by anotating #Produces("application/json")
Am Handling application errors with error codes. So i form an object with error code and error message. So when ever there is an application exception, it will produces in XML format. How can produce those in JSON format?

Answer 1

Yes You Can. Catch your Exception and handle it with your custom exception class and throw the exception class by setting response content type as application/json
try{
InitialContext ctx = new InitialContext();
TestIntf intf = (TestIntf)ctx.lookup("java:comp/env/ejb/TestImpl");
}catch(NamingException namingException) {
CustomException lookupException = new CustomException("SYSJNDIE001", namingException.getMessage());
throw lookupException;
}
And your Exception class would look like this
public class CustomException extends Exception {
private static final long serialVersionUID = -5358934896070563181L;
public CustomException(String errorCode, String message) {
super(errorCode, message);
}
}
Create a Provider class Mapper for Exception
#Provider
public class FaultResponseMapper implements ExceptionMapper<CustomException> {
#Context
private HttpHeaders headers;
#Override
public Response toResponse(CustomException customException) {
return Response.status(Response.Status.INTERNAL_SERVER_ERROR)
.entity(customException)
.type(MediaType.APPLICATION_JSON).build();
}
}