RestClientException 처리

public enum HttpStatus {
	
	...

	public Series series() {
		return Series.valueOf(this);
	}

	...

	public enum Series {

		INFORMATIONAL(1),
		SUCCESSFUL(2),
		REDIRECTION(3),
		CLIENT_ERROR(4),
		SERVER_ERROR(5);

		...

		public static Series valueOf(int status) {
			int seriesCode = status / 100;
			for (Series series : values()) {
				if (series.value == seriesCode) {
					return series;
				}
			}
			throw new IllegalArgumentException("No matching constant for [" + status + "]");
		}
	}
}	

try {
	ClientHttpRequest request = createRequest(url, method);
	if (requestCallback != null) {
		requestCallback.doWithRequest(request);
	}
	response = request.execute();
	handleResponse(url, method, response);
	if (responseExtractor != null) {
		return responseExtractor.extractData(response);
	}
	else {
		return null;
	}
}
catch (IOException ex) {

protected boolean hasError(HttpStatus statusCode) {
	return (statusCode.series() == HttpStatus.Series.CLIENT_ERROR || statusCode.series() == HttpStatus.Series.SERVER_ERROR);
}

try {
    responseBody = restTemplate.postForObject(url, httpEntity, byte[].class);
} catch (RestClientException e) { // 에러인 경우 RestClientException 을 내뱉는다.
    log.error("##### restTemplate error, url = {}", url, e);
}