String connectionDriver = "org.gjt.mm.mysql.Driver";

        try {
            Class.forName(connectionDriver); // there exc

            // Enable logging

            Connection connection = (Connection)
DriverManager.getConnection("jdbc:mysql://localhost:3306/jabber",
"root", "root");

            connection.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }

this code throw exception/ what does the bug?