servlet max

throws ServletException, IOException {
         String searchParam = request.getParameter("searchParam");
        if (searchParam == null || searchParam.trim().length()==0) {
            request.setAttribute("message","Please enter part of product name" );
            request.getRequestDispatcher("/shop.jsp").forward(request, response);
        }
        EntityManagerFactory emf = Persistence.createEntityManagerFactory("sit.int303.SCproject_SCproject_war_1.0-SNAPSHOTPU");
        EntityManager em = emf.createEntityManager();
        String sql = "SELECT p FROM Product p WHERE p.productname like :pn";
        Query qry = em.createQuery(sql);

        qry.setParameter("pn", "%"+ searchParam+ "%");
        List<Product> pd = qry.getResultList();
        request.setAttribute("allproduct",pd);
        request.getRequestDispatcher("/shop.jsp").forward(request, response);
    }