code: @Override
      protected String getFirst() {
          if (!rules_first.containsKey(getClass())) {
              for (Method method : getClass().getDeclaredMethods()) {
                  if (method.getDeclaredAnnotation(First.class) != null) {
                      rules_first.put(getClass(), method.getName());
                      LOG.info("[RuleController" + getClass().getName() + "]的第一步 = " + method.getName());
                      break;
                  }
              }
          }
          return rules_first.get(getClass());
      }
docs: 懒加载