Pegando tamanho de um arquivo,

private int getTotalSize(List newFiles) {
      int totalSize = 0;
        if (newFiles != null) {
            Iterator it = newFiles.iterator();
            VersionItem version;
            Iterator itDirs;
            DirectoryItem directory;
            List fileList;
            File file;
            while (it.hasNext()) {
                version = (VersionItem) it.next();
                itDirs = version.getDirectories().iterator();
                while (itDirs.hasNext()) {
                    directory = (DirectoryItem) itDirs.next();
                    fileList = directory.getFiles();
                    //pegar o valor de cada arquivo e colocar em totalSize
                }
            }
        }
        return totalSize;
    }