writeObject

    public static void writeObject(String filename, Object obj) {
        try {
            FileOutputStream fos =
                    new FileOutputStream("src/com/andalas/ser/" + filename);
            ObjectOutputStream oos = new ObjectOutputStream(fos);

            oos.writeObject(obj);
            oos.flush();
            oos.close();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }