Our standard REST services come with standard exception handling. This means that all server-side exceptions will send the http status code 400 (Bad Request) to the client. The implementation already checks some exception types and returns custom http status codes:

If you want custom status codes, it's possible to throw RestServiceException. This exception class supports custom status codes and error details.

if (!isBookingAvailable())
{
    IBean details = new Bean();
    details.put("id", errorId);
    details.put("message", "The booking feature isn't yet implemented!");
 
    throw new RestServiceException(501, details);
}
 
...