ResponseBuilder is not working when used with entity object

Question

I am trying to create a response with responsebuilder. When I pass string in entity it works fine but when I pass some error class it doesnot works.

Here is code

1) Working fine

Response.status(400).entity("test").build();

2) Not working

Response.status(400).entity(new MyCustomExceptions(400,"My bad request")).build();

With above code I am getting error

org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor aroundWriteTo
SEVERE: MessageBodyWriter not found for media type=text/plain

when I call this service with above code I am getting 500 error instead of 400.But in 1st case I am getting proper 400 error.

• Just wanted to understand if I pass object to entity then do I need to override some methods in class MyCustomExceptions?
• How response is created from MyCustomExceptions object?
• If I pass string to entity it works fine.Why?

Answer 1

Mapping exceptions to HTTP error responses

JAX-RS allows you to define a direct mapping of Java exceptions to HTTP error responses.

By extending WebApplicationException, you can create application specific exceptions that build a HTTP response with the status code and an optional message as the body of the response.

With that in mind, instead of returning a Response, you could throw a BadRequestException which extends WebApplicationException and will be mapped to a HTTP response with the status code 400:

throw new BadRequestException("My bad request");

For more details regarding error handling in JAX-RS, refer to this answer.

Subclasses of WebApplicationException

For convenience, the WebApplicationException is currently extended by the following exceptions (and they can be extended to create your own exceptions):

• RedirectionException: 3xx status codes for Redirection errors
• ClientErrorException: 4xx status codes for Client errors
  • BadRequestException: 400 Bad Request
  • ForbiddenException: 403 Forbidden
  • NotAcceptableException: 406 Not Acceptable
  • NotAllowedException: 405 Method Not Allowed
  • NotAuthorizedException: 401 Unauthorized
  • NotFoundException: 404 Not Found
  • NotSupportedException: 415 Unsupported Media Type
• ServerErrorException: 5xx status codes for Server errors
  • InternalServerErrorException: 500 Internal Server Error
  • ServiceUnavailableException: 503 Service Unavailable

Answer 2

What is the value of accept parameter in HTTPHeader that you're passing? Looks like its text/plain and you're trying to return an Object.

1. Pass the accept value as application/json in the request. OR

2. Change your code in response to add type as Json/XML

   Response.status(400).type(MediaType.APPLICATION_JSON).entity(new MyCustomExceptions(400,"My bad request")).build();