春季重试，无需春季申请

我发现我可以使用RetryTemplate：

    RetryTemplate retryTemplate = new RetryTemplate();    FixedBackOffPolicy fixedBackOffPolicy = new FixedBackOffPolicy();    fixedBackOffPolicy.setBackOffPeriod(2000l);    retryTemplate.setBackOffPolicy(fixedBackOffPolicy);    SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();    retryPolicy.setMaxAttempts(5);    retryTemplate.setRetryPolicy(retryPolicy);    retryTemplate.execute(new RetryCallback<Void, Throwable>() { @Override public Void doWithRetry(RetryContext context) throws Throwable {     // do some job     if(context.getRetryCount() < 3){ // unexpected disconnection         log.error("connection failed");         throw new RuntimeException("retry exception");      }     System.out.println("RETRY" + context);     return null; }        });