How to set up RestTemplate to retry calls on certain response status code?

I’ve trouble setting up a RestTemplate to retry remote calls. Does anyone know how to configure the RestTemplate to retry calls after getting 503 response status code?

Yes it is possible, you can try out custom retry policy.

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 503
				if (((HttpServerErrorException) classifiable).getStatusCode() == HttpStatus.SERVICE_UNAVAILABLE) {
					return simpleRetryPolicy;
				}
				return new NeverRetryPolicy();
			}
			return new NeverRetryPolicy();
		}
	});
}}

Ans the simply call it as below:

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

Retry within the catch block

try {
	responseEntity = restTemplate.exchange(endpoint, HttpMethod.POST, entity, MyResponse.class);
} catch (HttpClientErrorException hcee) {
	//There is an error in request, if known, improve and retry
} catch (HttpServerErrorException hsee) {
	recvdStatusCode = hsee.getStatusCode();
	// Handle it within a switch case, if there is an option to retry.
}

> This may be another approach, I have never tried this myself-

@Bean
  public RetryTemplate retryTemplate() {

    int maxAttempt = Integer.parseInt(env.getProperty("maxAttempt"));
    int retryTimeInterval = Integer.parseInt(env.getProperty("retryTimeInterval"));

    SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
    retryPolicy.setMaxAttempts(maxAttempt);

    FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy();
    backOffPolicy.setBackOffPeriod(retryTimeInterval); // 1.5 seconds

    RetryTemplate template = new RetryTemplate();
    template.setRetryPolicy(retryPolicy);
    template.setBackOffPolicy(backOffPolicy);

    return template;
  }

//Here is the invocation -

retryTemplate.execute(context -> {
        System.out.println("inside retry method");
        ResponseEntity<?> requestData = RestTemplateProvider.getInstance().postAsNewRequest(bundle, ServiceResponse.class, serivceURL,
                CommonUtils.getHeader("APP_Name"));

        _LOGGER.info("Response ..."+ requestData);
            throw new IllegalStateException("Something went wrong");
        });