Retry only on specific exception type using RetryTemplate not stopping at max attempt - Java Spring

Question

I am using Retry Template which should retries 5 times on DataAccessResourceFailureException and for every other, No retry.

        private static RetryTemplate setupRetryTemplate() { RetryTemplate template = new RetryTemplate();    
        // Set up backoff policy
        FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy();
        fixedBackOffPolicy.setBackOffPeriod(300L);
        template.setBackOffPolicy(fixedBackOffPolicy);
    
        // Set up retry policy based on exception type
        ExceptionClassifierRetryPolicy retryPolicy = new ExceptionClassifierRetryPolicy();
        retryPolicy.setExceptionClassifier(exception -> {
            // Retry only on specific exception type
            if (exception instanceof DataAccessResourceFailureException) {
                SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
                simpleRetryPolicy.setMaxAttempts(5);
                return simpleRetryPolicy;
            } else {
                return new NeverRetryPolicy(); // Do not retry for other exceptions
            }
        });
    
        template.setRetryPolicy(retryPolicy);
    
        return template;
    }

Caller of method looks like below

    public UserDetails loadUserByUsername(String username, Map<String, Object> attributes, String accountPickedClientId) throws UsernameNotFoundException {

        return retryTemplate.execute((RetryCallback<UserDetails, RuntimeException>) context -> {
            try { ...


            } catch (DataAccessResourceFailureException ex) {
                log.error("Exception DataAccessResourceFailureException :  {}", ex.getMessage(), ex);
                throw new DataAccessResourceFailureException("Mongo db connection time out");
            } catch (Exception ex) {
                log.error(USER_NOT_FOUND, ex);
                throw new UsernameNotFoundException(USER_NOT_FOUND, ex);
            }
    }

It's going into an infinite loop of retries.

Answer 1

You are creating a new policy for each exception so it starts over each time. You need to define the policy once and return the same instance for the required exception type.