DatabaseConnection.java

package POSmain;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DatabaseConnection {

    private static DatabaseConnection instance;
    private Connection connection;

    public static DatabaseConnection getInstance() {
        if (instance == null) {
            instance = new DatabaseConnection();
        }
        return instance;
    }

    private DatabaseConnection() {
    }

    public void connectToDatabase() throws SQLException {
        if (connection == null || connection.isClosed()) {
            String server = "localhost";
            String port = "3306";
            String database = "user_database";
            String userName = "root";
            String password = "123";

            try {
                connection = DriverManager.getConnection("jdbc:mysql://" + server + ":" + port + "/" + database, userName, password);
                System.out.println("Database Connected Successfully!");
            } catch (SQLException e) {
                System.err.println("Failed to connect to the database.");
                e.printStackTrace();
            }
        }
    }

    public Connection getConnection() {
        return connection;
    }
}