如何在Spring-retry（Spring Boot）中配置延遲時間

Question

是否可以配置@Retryable？此方法（getCurrentRate）將被調用3次。首先是5分鐘，之後10分鐘，最後15分鐘。我該如何配置？

@Retryable(maxAttempts=3,value=RuntimeException.class,backoff = @Backoff(delay = 1000)) 

例

public class RealExchangeRateCalculator implements ExchangeRateCalculator { 

    private static final double BASE_EXCHANGE_RATE = 1.09; 
    private int attempts = 0; 
    private SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss"); 

    @Retryable(maxAttempts=3,value=RuntimeException.class,backoff = @Backoff(delay = 1000)) 
    public Double getCurrentRate() { 

     System.out.println("Calculating - Attempt " + attempts + " at " + sdf.format(new Date())); 
     attempts++; 

     try { 
      HttpResponse<JsonNode> response = Unirest.get("http://rate-exchange.herokuapp.com/fetchRate") 
       .queryString("from", "EUR") 
       .queryString("to","USD") 
       .asJson(); 

      switch (response.getStatus()) { 
      case 200: 
       return response.getBody().getObject().getDouble("Rate"); 
      case 503: 
       throw new RuntimeException("Server Response: " + response.getStatus()); 
      default: 
       throw new IllegalStateException("Server not ready"); 
      } 
     } catch (UnirestException e) { 
      throw new RuntimeException(e); 
     } 
    } 

    @Recover 
    public Double recover(RuntimeException e){ 
     System.out.println("Recovering - returning safe value"); 
     return BASE_EXCHANGE_RATE; 
    } 

} 

Answer 1

可以實現與這種配置：

@Retryable(
    maxAttempts=3, 
    value=RuntimeException.class, 
    backoff = @Backoff(
    delay = 300000, 
    multiplier = 2, 
    maxDelay = 900000 
) 
) 

---

調用次數：

1. 後5米〜Delay = 300000
2. 後10米〜Delay = 300000 * 2 = 600000
3. 15米後〜Delay = 600000 * 2 = 1200000 with Max Delay of 900000