Is it possible to set RetryPolicy in spring-retry based on HttpStatus status code?

Question

Is it possible to set RetryPolicy in spring retry (https://github.com/spring-projects/spring-retry) based on error status code? e.g. I want to retry on HttpServerErrorException with HttpStatus.INTERNAL_SERVER_ERROR status code, which is 503. Therefore it should ignore all other error codes -- [500 - 502] and [504 - 511].

Answer 1

The RestTemplate has setErrorHandler option and DefaultResponseErrorHandler is the default one.

Its code looks like:

public void handleError(ClientHttpResponse response) throws IOException {
    HttpStatus statusCode = getHttpStatusCode(response);
    switch (statusCode.series()) {
        case CLIENT_ERROR:
            throw new HttpClientErrorException(statusCode, response.getStatusText(),
                    response.getHeaders(), getResponseBody(response), getCharset(response));
        case SERVER_ERROR:
            throw new HttpServerErrorException(statusCode, response.getStatusText(),
                    response.getHeaders(), getResponseBody(response), getCharset(response));
        default:
            throw new RestClientException("Unknown status code [" + statusCode + "]");
    }
}

So, you can provide your own implementation for that method to simplify your RetryPolicy around desired status codes.

Answer 2

For others who are facing same problem, I'm posting this answer. Implement custom retry policy as follows:

class InternalServerExceptionClassifierRetryPolicy extends ExceptionClassifierRetryPolicy {
public InternalServerExceptionClassifierRetryPolicy() {
    final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
    simpleRetryPolicy.setMaxAttempts(3);

    this.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
        @Override
        public RetryPolicy classify(Throwable classifiable) {
            if (classifiable instanceof HttpServerErrorException) {
                // For specifically 500 and 504
                if (((HttpServerErrorException) classifiable).getStatusCode() == HttpStatus.INTERNAL_SERVER_ERROR
                        || ((HttpServerErrorException) classifiable)
                                .getStatusCode() == HttpStatus.GATEWAY_TIMEOUT) {
                    return simpleRetryPolicy;
                }
                return new NeverRetryPolicy();
            }
            return new NeverRetryPolicy();
        }
    });
}}

Ans the simply call it as below:

RetryTemplate template = new RetryTemplate();
template.setRetryPolicy(new InternalServerExceptionClassifierRetryPolicy())

Answer 3

You can also add the specific error code in the retryableExceptions list of the SinmpleRetryPolicy.

Map<Class<? extends Throwable>, Boolean> retryableExceptions = new HashMap<>();
retryableExceptions.put(HttpClientErrorException.Unauthorized.class, true);
retryTemplate.setRetryPolicy(new SimpleRetryPolicy(5, retryableExceptions));