@Override
    public Connection openConnection() throws SQLException, ClassNotFoundException {
        if (checkConnection()) {
            return connection;
        }

        String connectionURL = "jdbc:mysql://" + this.hostname + ":" + this.port;
        if (database != null) {
            connectionURL = connectionURL + "/" + this.database;
        }

        Class.forName("com.mysql.jdbc.Driver");
        connection = DriverManager.getConnection(connectionURL, this.user, this.password);
        return connection;
    }