java - JAX-RS (Jersey) custom exception with XML or JSON

Question

I have a REST service built using Jersey.

I want to be able to set the MIME of my custom exception writers depending on the MIME that was sent to the server. application/json is returned when json is received, and application/xml when xml is received.

Now I hard code application/json, but that's making the XML clients left in the dark.

public class MyCustomException extends WebApplicationException {
     public MyCustomException(Status status, String message, String reason, int errorCode) {
         super(Response.status(status).
           entity(new ErrorResponseConverter(message, reason, errorCode)).
           type("application/json").build());
     }
}

What context can I tap into to get the current requests Content-Type?

Thanks!

---

Update based on answer

For anyone else interested in the complete solution:

public class MyCustomException extends RuntimeException {

    private String reason;
    private Status status;
    private int errorCode;

    public MyCustomException(String message, String reason, Status status, int errorCode) {
        super(message);
        this.reason = reason;
        this.status = status;
        this.errorCode = errorCode;
    }

    //Getters and setters
}

Together with an ExceptionMapper

@Provider
public class MyCustomExceptionMapper implements ExceptionMapper<MyCustomException> {

    @Context
    private HttpHeaders headers;

    public Response toResponse(MyCustomException e) {
        return Response.status(e.getStatus()).
                entity(new ErrorResponseConverter(e.getMessage(), e.getReason(), e.getErrorCode())).
                type(headers.getMediaType()).
                build();
    }
}

Where ErrorResponseConverter is a custom JAXB POJO

Answer 1

You can try adding a @javax.ws.rs.core.Context javax.ws.rs.core.HttpHeaders field/property to your root resource class, resource method parameter, or to a custom javax.ws.rs.ext.ExceptionMapper and calling HttpHeaders.getMediaType().