private File calcParentTree(){
  File parentTree=treeFile.getParentFile();
  if (null == parentTree) {
    return null;
  }
  if (treeFile.isAbsolute() && (null == parentTree.getParentFile())) {
    return null;
  }
  return parentTree;
}

private File calcParentTree ( ) { File parentTree = treeFile . getParentFile ( ) ; if ( null == parentTree ) { return null ; } if ( treeFile . isAbsolute ( ) && ( null == parentTree . getParentFile ( ) ) ) { return null ; } return parentTree ; }
determine if the current tree has a non - root parent . the trick is the non - root part , as the java library happily provides the root as a parent . but that leads to unanchored file names , which are not very useful .
