Retry java RestTemplate HTTP request if host offline

Question

Hi I\'m using the spring RestTemplate for calling a REST API. The API can be very slow or even offline. My application is building the cache by sending thousand

Answer 1

I had same situation and done some googling found the solution. Giving answer in hope it help someone else. You can set max try and time interval for each try.

@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;
  }

And my rest service that i want to execute is below.

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");
        });