private static long sizeOf0(File file) {
        if (file.isDirectory()) {
            return sizeOfDirectory0(file);
        } else {
            return file.length(); // will be 0 if file does not exist
        }
    }
the size of a file
@param file the file to check
@return the size of the fil
replugin-host-library/replugin-host-lib/src/main/java/com/qihoo360/replugin/utils/FileUtils.java