@ExceptionHandler(GemfireRestException.class)
  @ResponseBody
  @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
  public String handleException(final GemfireRestException ge) {
    return convertErrorAsJson(ge);
  }
Handles any GemfireRestException thrown by a REST API web service endpoint, HTTP request
handler method.
<p>

@param ge the GemfireRestException thrown when it found problem processing REST request.
@return the String message from the RuntimeException.
geode-web-api/src/main/java/org/apache/geode/rest/internal/web/controllers/BaseControllerAdvice.java