DB Hash Example

import java.awt.*;
import java.awt.event.*;
import java.sql.*;

import javax.swing.*;

public class SwingControlDemo {
    Connection conn = null;

    private JTextField usernameField;
    private JPasswordField passwordField;
    private JFrame mainFrame;

    public static void main(String[] args) {
        SwingControlDemo swingControlDemo = new SwingControlDemo();
        swingControlDemo.startGUI();
        swingControlDemo.addControlButtons();

    }

    private void startGUI() {
        mainFrame = new JFrame("Java SWING Examples");
        mainFrame.setSize(300, 120);
        mainFrame.setLocation(300, 300);
        mainFrame.setLayout(new GridLayout(3, 1));
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JLabel usernameLabel = new JLabel("Username:");
        usernameField = new JTextField(10);
        passwordField = new JPasswordField(10);
        JLabel passwordLabel = new JLabel("Password:");

        JPanel usernamePanel = new JPanel();
        usernamePanel.setLayout(new FlowLayout(FlowLayout.CENTER));
        usernamePanel.add(usernameLabel);
        usernamePanel.add(usernameField);

        JPanel passwordPanel = new JPanel();
        passwordPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
        passwordPanel.add(passwordLabel);
        passwordPanel.add(passwordField);

        mainFrame.add(usernamePanel);
        mainFrame.add(passwordPanel);

        mainFrame.setVisible(true);
    }

    private void addControlButtons() {
        JButton loginButtong = new JButton("Login");
        JButton registerButton = new JButton("Register");

        JPanel controlPanel = new JPanel();

        controlPanel.setLayout(new FlowLayout(FlowLayout.CENTER));
        controlPanel.add(loginButtong);
        controlPanel.add(registerButton);

        loginButtong.setActionCommand("Login");
        registerButton.setActionCommand("Register");
        loginButtong.addActionListener(new ButtonClickListener());
        registerButton.addActionListener(new ButtonClickListener());
        mainFrame.add(controlPanel);
        mainFrame.setVisible(true);
    }

    private class ButtonClickListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            String command = e.getActionCommand();
            if (command.equals("Login")) {
                // task 5 start
                try {
                    Class.forName("org.h2.Driver");
                    Connection conn = DriverManager.getConnection("jdbc:h2:~/test", "sa", "sa");
                    Statement st = conn.createStatement();
                    String tmpusername = usernameField.getText();
                    String SALT;
                    SALT = "$2a$12$lJFY15CtsjiK9TE5as8qKO";
                    String generatedPassword = BCrypt.hashpw(passwordField.getText(), SALT);
                    String query = "SELECT * FROM Users WHERE username= '" + tmpusername + "' and password='"+ generatedPassword +"';";
                    ResultSet rs = st.executeQuery(query);
                    if (rs.next()) {
                        JOptionPane.showMessageDialog(null, "Username and Password are correct");
                    } else {
                        JOptionPane.showMessageDialog(null, "Username and Password are incorrect, try again!");
                    }
                    rs.close();
                    conn.close();
                } catch (ClassNotFoundException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                } catch (SQLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            } else if (command.equals("Register")) {

                try {
                    Class.forName("org.h2.Driver");
                    Connection conn = DriverManager.getConnection("jdbc:h2:~/test", "sa", "sa");
                    Statement st = conn.createStatement();
                    // We want to check if the user already exists.
                    String tmpusername = usernameField.getText();
                    String checkquery = "SELECT * FROM Users WHERE username='" + tmpusername + "';";
                    ResultSet rs = st.executeQuery(checkquery);
                    if (rs.next() == true) {
                        JOptionPane.showMessageDialog(null, "Username exists, try another name");
                    } else {
                        String SALT = "$2a$12$lJFY15CtsjiK9TE5as8qKO";
                        String generatedPassword = BCrypt.hashpw(passwordField.getText(), SALT);
                        String insertQuery = "INSERT INTO Users (username, password) VALUES('" + tmpusername + "', '"
                                + generatedPassword + "');";
                        int n = st.executeUpdate(insertQuery);
                        if (n == 1) {
                            JOptionPane.showMessageDialog(null, "You have been successfully registered!!");
                        } else {
                            JOptionPane.showMessageDialog(null, "Oops something went wrong");
                        }
                    }
                    rs.close();
                    st.close();
                    conn.close();
                } catch (ClassNotFoundException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                } catch (SQLException e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }

            }

        }
    }
}