ConfigFileUtils { public static String getClusterName(final String originalFilename) { checkThreePart(originalFilename); return getThreePart(originalFilename)[1]; }  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 getClusterName() { final String cluster = ConfigFileUtils.getClusterName("application+default+application.properties"); assertEquals("default", cluster); final String Beijing = ConfigFileUtils.getClusterName("abc+Beijing+application.yml"); assertEquals("Beijing", Beijing); }