public class DBConnect {

    private static final String DRIVER = "org.sqlite.JDBC";
    private static final String DB_URL = "jdbc:sqlite:database.db";

    private static volatile Connection connection = null;

    public static Connection getConnection() {
        if (connection == null) {
            synchronized (DBConnect.class) {
                if (connection == null) {
                    try {
                Class.forName(DRIVER);
                connection = DriverManager.getConnection(DB_URL);
            } catch (ClassNotFoundException | SQLException e) {
                e.printStackTrace();
                return null;
            }
                }
            }
        }
        return connection;
    }
}