public abstract class DAOFactory {
    public static final int MYSQL = 1;
    public static final int CASSANDRA = 2;

    public abstract EventVariableDAO getEventVariableDAO();
    public abstract SessionVariableDAO getSessionVariableDAO();
    public abstract UserVariableDAO getUserVariableDAO();
    public abstract VisitorDAO getVisitorDAO();
    public abstract VisitDAO getVisitDAO();
    public abstract RequestDAO getRequestDAO();

    public static DAOFactory getDAOFactory(int whichFactory) {
        switch (whichFactory) {
            case MYSQL:
                return new MysqlDAOFactory();

            case CASSANDRA:
                return new CassandraDAOFactory();

            default:
                return null;
        }
    }
}