public class LoginScreen extends JFrame implements Observer {
private JLabel lblTitle, lblUsername, lblPassword;
private JTextField txtVanReg;
private JPasswordField txtPassword;
private JPanel pnlCenter, pnlNorth;
private JButton btnLogin, btnCancel;
private final Font fntOther = new Font("Verdana", Font.PLAIN, 16);
private final Font fntTitle = new Font("Verdana", Font.PLAIN, 20);
private LoginController controller;

public LoginScreen() {
    this.controller = new LoginController(this);
    this.setTitle("Login");
    this.setLayout(new BorderLayout());

    setUpComponents();
}

private void setUpComponents() {

    lblTitle = new JLabel("Burrito Business");
    lblUsername = new JLabel("Van reg: ");
    lblPassword = new JLabel("Password: ");

    txtVanReg = new JTextField();
    txtPassword = new JPasswordField();

    btnLogin = new JButton("Login");
    btnCancel = new JButton("Cancel");

    btnLogin.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent e) {
            controller.loginRequested(txtVanReg.getText(), txtPassword.getPassword());
        }
    });

    btnCancel.addActionListener(new ActionListener() {

        public void actionPerformed(ActionEvent e) {
            controller.loginCancelled();

        }
    });


    pnlCenter = new JPanel(new GridLayout(3, 3));
    pnlNorth = new JPanel(new BorderLayout());

    pnlCenter.add(lblUsername);
    pnlCenter.add(txtVanReg);
    pnlCenter.add(lblPassword);
    pnlCenter.add(txtPassword);
    pnlCenter.add(btnLogin);
    pnlCenter.add(btnCancel);

    pnlNorth.add(lblTitle);
    setFonts();

    this.add(pnlNorth, BorderLayout.NORTH);
    this.add(pnlCenter, BorderLayout.CENTER);

    this.setMinimumSize(new Dimension(400, 150));
    this.setResizable(false);

}

private void setFonts() {

    lblTitle.setFont(fntTitle);

    lblUsername.setFont(fntOther);
    lblPassword.setFont(fntOther);
    txtVanReg.setFont(fntOther);
    txtPassword.setFont(fntOther);

    btnLogin.setFont(fntOther);
    btnCancel.setFont(fntOther);

}

/*
 * (non-Javadoc)
 *
 * @see java.util.Observer#update(java.util.Observable, java.lang.Object)
 */
public void update(Observable o, Object arg) {
    if (o instanceof DBUserAuth && ((Boolean) arg).booleanValue() == true) {
        JOptionPane.showMessageDialog(new JFrame(), "Login successful");

    } else {
        JOptionPane.showMessageDialog(new JFrame(), "Login failed");
    }

}

public char[] getPassword() {
    return this.txtPassword.getPassword();
}

public String getVanReg() {
    return this.txtVanReg.getText();
}

public void close() {
    this.dispatchEvent(new WindowEvent(this, WindowEvent.WINDOW_CLOSING));
}

public class LoginController {
private DBUserAuth dbConnection;
private LoginScreen view;

public LoginController(LoginScreen view) {
    dbConnection = new DBUserAuth();
    this.view = view;
    dbConnection.addObserver(view);
}

public void loginRequested(String van_reg, char[] password) {
        String pass = "";

        for (char a : password) {
            pass += a;
        }

        if (dbConnection.checkUser(van_reg, pass)) {
            StaffMenu aMenu = new StaffMenu(van_reg);
            aMenu.setVisible(true);
            view.close();
        }


}

public void loginCancelled() {
    view.close();
}

public class DBUserAuth extends Observable {

private Properties props;
private Connection con;
private String url, password, username;
private PreparedStatement loginAuthStatement, addTruckStatement;
private ResultSet results;

/**
 * Loads the properties file and gets the url, username and the password
 * from the file. Then goes on to open a connection to the database.
 */
public DBUserAuth() {

    // 1. Load properties in
    props = new Properties();
    ClassLoader loader = Thread.currentThread().getContextClassLoader();
    InputStream stream = loader.getResourceAsStream("prop.properties");

    try {
        props.load(stream);
        url = props.getProperty("db.url");
        username = props.getProperty("db.username");
        password = props.getProperty("db.password");
    } catch (IOException e) {
        e.printStackTrace();
        System.out.println("Failed to load properties");
    }

}

/**
 * Used to connect to the DB
 *
 * @return True if success, false otherwise
 */
private boolean openConnection() {
    try {
        con = DriverManager.getConnection(url, username, password);
        // connect to the db
        System.out.println("Connected to the DB");
        return true;
    } catch (SQLException e) {
        e.printStackTrace();
        System.out.println("Failed to connect to the DB");
        return false;
    }
}

/**
 * Used to close connection to the DB
 *
 * @return True if success, false otherwise
 */
private boolean closeConnection() {
    try {
        con.close();
        return true;
    } catch (SQLException e) {
        e.printStackTrace();
        return false;
    }
}

/**
 *
 * @param password
 *            the proposed password i.e. the password to check
 * @return
 */
public boolean checkUser(String username, String password) {
    long time13 = System.currentTimeMillis();
    long time14;
    try {
        openConnection();
        loginAuthStatement = con.prepareStatement(
                "SELECT Van_reg_no, Hashed_Password FROM Food_Truck WHERE Van_reg_no LIKE ? ORDER BY Van_reg_no ASC");
        loginAuthStatement.setString(1, "%" + username + "%");

        results = loginAuthStatement.executeQuery();

        results.beforeFirst();

        while (results.next()) {
            String reg = results.getString(1);
            String hashPassword = results.getString(2);

            if (reg.equals(username) && BCrypt.checkpw(password, hashPassword)) {
                System.out.println("Login passed");

                time14 = System.currentTimeMillis();
                System.out.println("Total login time: " + (time14 - time13) + " miliseconds.");
                setChanged();
                notifyObservers(new Boolean(true));
                return true;
            }
        }

    } catch (SQLException e) {
        System.out.println("SQL for user auth. failed");
        e.printStackTrace();
    } finally {
        closeConnection();
    }
    setChanged();
    notifyObservers(new Boolean(false));

    time14 = System.currentTimeMillis();

    System.out.println("Total login time: " + (time14 - time13) + " miliseconds.");
    return false;
}
}