dis.close();
    private static Credentials loadCredentials(String realm, int index) {        File file = getCrendentialsFile(realm, index);        if (!file.exists()) {            return null;        }        try {            DataInputStream dis = new DataInputStream(new FileInputStream(file));            String name = dis.readUTF();            String password = dis.readUTF();            dis.close();            return new Credentials(name, password);        } catch (IOException e) {        }        return null;    }