apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/util/ConfigFileUtils.java/ConfigFileUtils/checkThreePart
class ConfigFileUtils:  static void checkThreePart(final String originalFilename) {
    String[] parts = getThreePart(originalFilename);
    if (3 != parts.length) {
      throw new BadRequestException("file name [" + originalFilename + "] not valid");
    }
  }