BalanceEnquiry.java

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

public class BalanceEnquiry extends JFrame {
    BalanceEnquiry(String cardNumber) {
        setTitle("Balance Enquiry");
        setLayout(new BorderLayout());

        JLabel label = new JLabel("", JLabel.CENTER);
        label.setFont(new Font("Arial", Font.BOLD, 18));
        add(label, BorderLayout.CENTER);

        try {
            Conn conn = new Conn();
            ResultSet rs = conn.s.executeQuery("SELECT * FROM bank WHERE card_number = '" + cardNumber + "'");
            int balance = 0;
            while (rs.next()) {
                String type = rs.getString("type");
                int amount = Integer.parseInt(rs.getString("amount"));
                balance += type.equals("Deposit") ? amount : -amount;
            }

            label.setText("Current Balance: Rs. " + balance);

        } catch (Exception e) {
            label.setText("Error fetching balance.");
            e.printStackTrace();
        }

        setSize(400, 200);
        setLocation(500, 300);
        setVisible(true);
    }

    public static void main(String[] args) {
        new BalanceEnquiry("1234567890123456");
    }
}