code: public static String messageOrDefault(String key, String defaultValue) {
          String localizationKey = Mvcs.getLocalizationKey() == null ? Mvcs.getDefaultLocalizationKey() : Mvcs.getLocalizationKey();
          Map<String, Object> localization = Mvcs.getLocaleMessage(localizationKey);
          if (null != localization) {
              Object value = localization.get(key);
              return value == null ? defaultValue : String.valueOf(value);
          }
          return defaultValue;
      }
docs: 取得国际化信息
  
  @param key
  @return