Bagaimana untuk melaksanakan sistem pusat beli-belah dalam talian pembesar suara Little Bee di Jawa

public class UserServlet extends BaseBackServlet {
 
    @Override
    public String add(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 UserServlet add方法");
        return null;
    }
 
    @Override
    public String delete(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 UserServlet delete方法");
 
        int id = Integer.parseInt(request.getParameter("id"));
        userDAO.delete(id);
        return "@admin_user_list";
    }
 
    @Override
    public String update(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 UserServlet update方法");
 
        Map<String, String> params = new HashMap<>();
        InputStream is = super.parseUpload(request, params);
        System.out.println(params);
 
        int id = Integer.parseInt(params.get("id"));
        String password = params.get("password");
 
        User user = userDAO.get(id);
        user.setPassword(password);
 
        userDAO.update(user);
 
        return "@admin_user_list";
    }
 
    @Override
    public String edit(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 UserServlet edit方法");
 
        int id = Integer.parseInt(request.getParameter("id"));
        User u = userDAO.get(id);
 
        request.setAttribute("u", u);
 
        return "admin/editUser.jsp";
    }
 
    @Override
    public String list(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 UserServlet list方法");
 
        List<User> us = userDAO.list(page.getStart(), page.getCount());
        int total = userDAO.getTotal();
        page.setTotal(total);
 
        request.setAttribute("us", us);
        request.setAttribute("page", page);
 
        return "admin/listUser.jsp";
    }
}

public class OrderServlet extends BaseBackServlet {
 
    @Override
    public String add(HttpServletRequest request, HttpServletResponse response, Page page) {
        return null;
    }
 
    @Override
    public String delete(HttpServletRequest request, HttpServletResponse response, Page page) {
        return null;
    }
 
    @Override
    public String update(HttpServletRequest request, HttpServletResponse response, Page page) {
        return null;
    }
 
    @Override
    public String edit(HttpServletRequest request, HttpServletResponse response, Page page) {
        return null;
    }
 
    public String delivery(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 OrderServlet delivery方法");
 
        int id = Integer.parseInt(request.getParameter("id"));
        Order o = orderDAO.get(id);
        o.setDeliveryDate(new Date());
        o.setStatus(OrderDAO.waitConfirm);
        orderDAO.update(o);
        return "@admin_order_list";
    }
 
    @Override
    public String list(HttpServletRequest request, HttpServletResponse response, Page page) {
        System.out.println("调用了 OrderServlet list方法");
 
        // 对订单对应的订单项进行初始化
        List<Order> os = orderDAO.list(page.getStart(), page.getCount());
        orderItemDAO.fill(os);
 
        int total = orderDAO.getTotal();
        page.setTotal(total);
 
        request.setAttribute("os", os);
        request.setAttribute("page", page);
 
        return "admin/listOrder.jsp";
    }
}