Question

我试图让用户输入某个项目代码，然后将其带到一个页面，在那里他们可以根据输入的代码从数据库中查看代码和项目信息。在第二页上，我希望用户能够使用另一个提交按钮输入另一个项目代码（在表格下），该按钮将使用他们添加的另一个项目来更新表格，该项目从数据库中获取。如何在不丢失桌面上的先前数据的情况下执行此操作？

到目前为止

代码：

    <%@page contentType="text/html" pageEncoding="UTF-8"%>
    <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 
    <!DOCTYPE html>
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Scanned Items</title>
    </head>
    <body> 
    <h1 align="center"><u><font color="blue">List of Scanned Items</font></u></h1>

    <table align="center">
        <tr>
            <th> Item Code </th>
            <th> Name </th>
            <th> Price </th>
            <th> Taxable </th>
            <th> Tax </th>
        </tr>
                <tr>
                    <td> ${productcatalogue.code}</td>
                    <td> ${productcatalogue.name}</td>
                    <td> $${productcatalogue.price}</td>
                    <td> ${productcatalogue.taxable}</td>
                    <td> </td>
                </tr>
    </table>
</body>
</html>

Servlet代码：

protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

    DBConnection dbConn = (DBConnection)request.getServletContext()
        .getAttribute("dbConn");

    ProductCatalogueDAO productcatalogueDAO = new ProductCatalogueDAO();
    String itemcode = request.getParameter("itemcode");
    ProductCatalogue productcatalogue = productcatalogueDAO.getItems(dbConn.getConnection(), itemcode);
    request.setAttribute("productcatalogue", productcatalogue);

    RequestDispatcher view = request.getRequestDispatcher
    (response.encodeURL("scannedItems.jsp"));
    view.forward(request, response);  
}

Answer 1

我可以给你概述来处理它，我只是没有使用数据库   存储它，但剩下的东西我做了。

按照这个顺序，您将获得解决方案，

只需创建一个jsp文件，在我的情况下， a1.jsp

------------------------ a1.jsp代码---------------- -----------------

<%@page import="java.util.ArrayList"%> <%@page import="com.stackoverflow.ItemBean"%> <%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> <table border="2"> <tr> <th>Item Code</th> <th>Name</th> <th>Price</th> <th>Taxable</th> <th>Tax</th> <th>Action</th> </tr> <% ArrayList<ItemBean> list = new ArrayList<ItemBean>(); if(session.getAttribute("allitems") != null){ list = (ArrayList<ItemBean>)session.getAttribute("allitems"); } for(ItemBean ib : list){ %> <tr> <td><%= ib.getItemCode() %></td> <td><%= ib.getItemname() %></td> <td><%= ib.getPrice() %></td> <td><%= ib.getTaxable() %></td> <td><%= ib.getTax() %></td> <td><i>Saved</i></td> </tr> <%}%> <form action="ItemSubmit.do" method="post"> <tr> <td><input type="text" name="itemCode" value="" /></td> <td><input type="text" name="itemname" value="" /></td> <td><input type="text" name="price" value="" /></td> <td><select name="taxable"> <option value="yes">Yes</option> <option value="no">No</option> </select></td> <td><input type="text" name="tax" value="" /></td> <td><input type="submit" value="Add" /></td> </tr> </form> </table> </body> </html>

--------------- ItemSubmit.java servlet代码-----------------

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); ArrayList<ItemBean> listBean = new ArrayList<ItemBean>(); String itemCode = request.getParameter("itemCode"); String itemname = request.getParameter("itemname"); double price = 0; String taxable = request.getParameter("taxable"); double tax = 0; String remark = "saved"; try { price = Double.parseDouble(request.getParameter("price")) ; tax = Double.parseDouble(request.getParameter("tax")); } catch (Exception e) { remark = e.getMessage(); } if(session.getAttribute("allitems") != null){ listBean = (ArrayList<ItemBean>)session.getAttribute("allitems"); } ItemBean itemBean = new ItemBean(itemCode, itemname, price, taxable, tax,remark); //save itemBean to DB-if needed then... listBean.add(itemBean); session.setAttribute("allitems",listBean); request.getRequestDispatcher("/a1.jsp").forward(request, response); }

-------------------- ItemBean.java普通java类---------------

package com.stackoverflow; public class ItemBean { String itemCode; String itemname; double price; String taxable; double tax; String remark; public ItemBean(String itemCode, String itemname, double price, String taxable,double tax , String remark ) { this.itemCode = itemCode; this.itemname = itemname; this.price = price; this.taxable = taxable; this.tax = tax; this.remark = remark; } public String getItemCode() { return itemCode; } public void setItemCode(String itemCode) { this.itemCode = itemCode; } public String getItemname() { return itemname; } public void setItemname(String itemname) { this.itemname = itemname; } public double getPrice() { return price; } public void setPrice(double price) { this.price = price; } public String getTaxable() { return taxable; } public void setTaxable(String taxable) { this.taxable = taxable; } public double getTax() { return tax; } public void setTax(double tax) { this.tax = tax; } public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } }

--------------- OUT-PUT --------------------

从第二页中的表单收集输入，而不会丢失第一页中表单的输入

1 个答案: