Slip No 19 Q B

Write a Java program to display first record from student table (rno, sname, per) onto the TextFields by clicking on button. (Assume Student table is already created).

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

public class StudentRecordDisplay extends JFrame implements ActionListener {

    // Labels
    JLabel lRno, lName, lPer;

    // TextFields
    JTextField tRno, tName, tPer;

    // Button
    JButton btnFirst;

    // JDBC
    Connection con;
    Statement stmt;
    ResultSet rs;

    public StudentRecordDisplay() {
        // Frame setup
        setTitle("Student Record Display");
        setSize(400, 250);
        setLayout(new GridLayout(4, 2, 10, 10));
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Initialize Labels
        lRno = new JLabel("Roll No:");
        lName = new JLabel("Name:");
        lPer = new JLabel("Percentage:");

        // Initialize TextFields
        tRno = new JTextField();
        tName = new JTextField();
        tPer = new JTextField();

        // Make textfields non-editable
        tRno.setEditable(false);
        tName.setEditable(false);
        tPer.setEditable(false);

        // Initialize Button
        btnFirst = new JButton("Show First Record");
        btnFirst.addActionListener(this);

        // Add components to frame
        add(lRno); add(tRno);
        add(lName); add(tName);
        add(lPer); add(tPer);
        add(new JLabel()); add(btnFirst); // Empty label for spacing

        // Make frame visible
        setVisible(true);

        // Setup JDBC
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/testdb", "root", "root");
            stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
            rs = stmt.executeQuery("SELECT * FROM Student");
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Database Error: " + e);
        }
    }

    @Override
    public void actionPerformed(ActionEvent ae) {
        try {
            if(rs != null && rs.first()) { // Move cursor to first record
                tRno.setText(String.valueOf(rs.getInt("rno")));
                tName.setText(rs.getString("sname"));
                tPer.setText(String.valueOf(rs.getDouble("per")));
            }
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Error: " + e);
        }
    }

    public static void main(String[] args) {
        new StudentRecordDisplay();
    }
}