code: public static List<String> getMatchingFileNames(String root, String filterExpr, boolean fullPath) {
          List<File> fileList = getMatchingFiles(root, filterExpr);
          List<String> list = new ArrayList<String>(fileList.size());
  
          for (File f : fileList) {
              if (fullPath)
                  list.add(f.getAbsolutePath());
              else
                  list.add(f.getName());
          }
  
          return list;
      }
docs: Get a list of file names from the given path that match the provided
  filter; not recursive.
  
  @param root
  base directory to look for files
  @param filterExpr
  the regular expression to match, may be null
  @return List of File objects; List will be empty if root is null