I am trying to get to the best way to wrap spring-retry @Retryable annotation around external service call. Here is my code:

@Retryable(exclude = HttpClientErrorException.BadRequest.class, value = RestClientException.class)
private ResponseEntity<Item> retrieveItemById(String id) 
{
    HttpHeaders headers = new HttpHeaders();
    try {
        return restTemplate.exchange(httpConnectionProperties.getBaseUrl()   "/items",
                HttpMethod.GET, new HttpEntity<>(item, headers), Item.class, id);
    } 
    catch (RestClientException e) {
        log.error("Exception occurred while retrieving an item" , e);
        return new ResponseEntity<>(HttpStatus.NOT_FOUND);
    }
}

I have a few questions on what happens when a RestClientException occurs :

1. Is the catch block executed before retry kicks in or does the retry kicks in before the catch block execution? Do I need a recovery block?
2. Probably more of an exception handling question - Is there a way to differentiate between an actual retry worthy scenario (service momentarily down, network issues, I/O error etc.) vs exception occurring due to lack of presence of an item in the above case?

CodePudding user response：

Since you are catching and "handling" the exception, retry is disabled; retry will only work if the method throws an exception.

To change the result (instead of throwing the exception to the caller when retries are exhausted, you need a @Recover method.

Not retryable exceptions will go straight there; you can have multiple @Recover methods for different exception types, or one generic one and you can check the exception type yourself.