connect database - class MyFame

package nguyenvanquan7826.database;

import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.JobAttributes;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextField;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.DefaultTableModel;

import jdk.nashorn.internal.scripts.JO;

public class MyFrame extends JFrame implements ActionListener {

    private boolean isUpdate = false;

    private JTable table;
    private JTextField tfId, tfName, tfPoint;
    private JButton btnOk;
    private JButton btnCancel;
    MyConnect myConnect = new MyConnect();

    public MyFrame() {
        // add main panel to JFrame
        add(createMainPanel());
        setDisplayInput(false, false);

        // connect database
        myConnect.connect();

        // set dipslay
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

    // create main panel
    private JPanel createMainPanel() {
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(createTitlePanel(), BorderLayout.PAGE_START);
        panel.add(createTablePanel(), BorderLayout.CENTER);
        panel.add(createBottomPanel(), BorderLayout.PAGE_END);
        return panel;
    }

    // create title panel
    private JPanel createTitlePanel() {
        JPanel panel = new JPanel();
        JLabel lbTitle = new JLabel("Connect Database");
        panel.add(lbTitle);
        return panel;
    }

    // create table panel
    private JPanel createTablePanel() {
        JPanel panel = new JPanel();
        panel.add(new JScrollPane(table = createTabel()));
        return panel;
    }

    // create button panel
    private JPanel createBottomPanel() {
        JPanel panel = new JPanel(new BorderLayout(10, 10));
        panel.setBorder(new EmptyBorder(5, 70, 10, 70));
        panel.add(createInputPanel(), BorderLayout.CENTER);
        panel.add(createButtonPanel(), BorderLayout.PAGE_END);
        return panel;
    }

    private JPanel createInputPanel() {
        JPanel panel = new JPanel(new BorderLayout(10, 10));

        // panel left
        JPanel panelLeft = new JPanel(new GridLayout(3, 1, 5, 5));
        panelLeft.add(new JLabel("Id"));
        panelLeft.add(new JLabel("Name"));
        panelLeft.add(new JLabel("Point"));

        // panel right
        JPanel panelRight = new JPanel(new GridLayout(3, 1, 5, 5));
        panelRight.add(tfId = new JTextField());
        panelRight.add(tfName = new JTextField());
        panelRight.add(tfPoint = new JTextField());

        // panel ok
        JPanel panelOk = new JPanel(new GridLayout(1, 2, 5, 5));
        panelOk.setBorder(new EmptyBorder(0, 50, 0, 50));
        panelOk.add(btnOk = createButton("Ok"));
        panelOk.add(btnCancel = createButton("Cancel"));

        panel.add(panelLeft, BorderLayout.WEST);
        panel.add(panelRight, BorderLayout.CENTER);
        panel.add(panelOk, BorderLayout.PAGE_END);
        return panel;
    }

    private JPanel createButtonPanel() {
        JPanel panel = new JPanel(new GridLayout(1, 3, 5, 5));
        panel.add(createButton("Add"));
        panel.add(createButton("Update"));
        panel.add(createButton("Delete"));
        return panel;
    }

    // create a table
    private JTable createTabel() {
        JTable table = new JTable();
        return table;
    }

    // create a button
    private JButton createButton(String text) {
        JButton btn = new JButton(text);
        btn.addActionListener(this);
        return btn;
    }

    private boolean setDisplayInput(boolean display, boolean update) {
        if (update && table.getSelectedRow() < 0) {
            return false;
        } else if (update) {
            int row = table.getSelectedRow();
            tfId.setText((String) table.getValueAt(row, 0));
            tfName.setText((String) table.getValueAt(row, 1));
            tfPoint.setText((String) table.getValueAt(row, 2));
        }
        tfId.setEnabled(display);
        tfName.setEnabled(display);
        tfPoint.setEnabled(display);
        btnOk.setEnabled(display);
        btnCancel.setEnabled(display);

        return true;

    }

    private void loadData() {
        // create table model
        DefaultTableModel model = new DefaultTableModel();

        // get data from database
        ResultSet rs = myConnect.getData();
        try {
            // load column name
            ResultSetMetaData rsMD = rs.getMetaData();
            int colNumber = rsMD.getColumnCount();
            String[] arr = new String[colNumber];
            for (int i = 0; i < colNumber; i++) {
                arr[i] = rsMD.getColumnName(i + 1);
            }
            model.setColumnIdentifiers(arr);

            // load data from database to table
            while (rs.next()) {
                for (int i = 0; i < colNumber; i++) {
                    arr[i] = rs.getString(i + 1);
                }
                model.addRow(arr);
            }

        } catch (SQLException e) {
        }
        table.setModel(model);
    }

    private void delete() {
        int row = table.getSelectedRow();
        if (row < 0) {
            JOptionPane.showMessageDialog(null,
                    "You must select a row in table", "Error delete",
                    JOptionPane.ERROR_MESSAGE);
            return;
        }
        int select = JOptionPane.showOptionDialog(null, "Are you want delet?",
                "Delete", 0, JOptionPane.YES_NO_OPTION, null, null, 1);
        if (select == 0) {
            myConnect.deleteId((String) table.getValueAt(row, 0));
            loadData();
        }
    }

    private Student getStudent() {
        String id = tfId.getText().trim().toUpperCase();
        String name = tfName.getText().trim();

        if (id.equals("") || name.equals("")) {
            return null;
        }

        double point;
        try {
            point = Double.parseDouble(tfPoint.getText().trim());
        } catch (Exception e) {
            return null;
        }

        Student st = new Student(id, name, point);
        return st;
    }

    private void update() {
        if (setDisplayInput(true, true)) {
            isUpdate = true;
        } else {
            JOptionPane.showMessageDialog(null, "Error update", "Error update",
                    JOptionPane.ERROR_MESSAGE);
        }
    }

    private void add() {
        setDisplayInput(true, false);
    }

    private void addOrUpdate() {
        Student st = getStudent();
        if (st != null) {
            if (isUpdate) {
                myConnect.updateId(st.getId(), st);
                loadData();
                isUpdate = false;
            } else {
                myConnect.insert(st);
                loadData();
            }
            clear();
            setDisplayInput(false, false);
        } else {
            JOptionPane.showMessageDialog(null, "Infomation is error",
                    "Error info", JOptionPane.ERROR_MESSAGE);
        }

    }

    private void clear() {
        tfId.setText("");
        tfName.setText("");
        tfPoint.setText("");
    }

    private void cancel() {
        clear();
        setDisplayInput(false, false);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getActionCommand() == "Delete") {
            delete();
            return;
        }
        if (e.getActionCommand() == "Update") {
            update();
            return;
        }
        if (e.getActionCommand() == "Add") {
            add();
            return;
        }
        if (e.getSource() == btnOk) {
            addOrUpdate();
        }

        if (e.getSource() == btnCancel) {
            cancel();
        }

    }

    public static void main(String[] args) {
        MyFrame myFrame = new MyFrame();
        myFrame.loadData();
    }

}