public static FileObject[] getChildren(FileObject fileObject) throws FileSystemException {
    FileObject[] result;
    final FileType type = fileObject.getType();
    LOGGER.debug("fileType is {}", type);
    if (isHttpProtocol(fileObject)) {
      result = extractHttpFileObjectChildren(fileObject);
    } else if (isLocalFileSystem(fileObject) && isArchive(fileObject)) {
      String extension = fileObject.getName().getExtension();
      result = VFSUtils.resolveFileObject(extension + ":" + fileObject.getURL().toString() + "!/").getChildren();
    } else {
      result = fileObject.getChildren();
    }
    return result;
  }
Returns whether a folder contains a given file

@param folder A folder
@param file   A file
@return whether a folder contains a given file
olv-vfs/src/main/java/pl/otros/vfs/browser/util/VFSUtils.java