ConfigFileUtils { public static String getAppId(final String originalFilename) { checkThreePart(originalFilename); return getThreePart(originalFilename)[0]; }  static void check(MultipartFile file); static String getFormat(final String originalFilename); static String getAppId(final String originalFilename); static String getClusterName(final String originalFilename); static String getNamespace(final String originalFilename); static String toFilename(
      final String appId,
      final String clusterName,
      final String namespace,
      final ConfigFileFormat configFileFormat
  ); static String toFilePath(
      final String ownerName,
      final String appId,
      final Env env,
      final String configFilename
  );  }
@Test public void getAppId() { final String application = ConfigFileUtils.getAppId("application+default+application.properties"); assertEquals("application", application); final String abc = ConfigFileUtils.getAppId("abc+default+application.yml"); assertEquals("abc", abc); }