JSP（6）简单购物车实现

古城微笑少年丶 2024-02-17 21:33 14阅读 0赞

两个jsp页面之间跳转需要通过Servlet控制器实现

### 1 创建数据库表 ###

-- 创建一个序列，使book的id自增长
    create sequence book_seq 
    start with 1
    increment by 1
    minvalue 1
    maxvalue 99999999999999
    nocycle
    nocache
    -- 创建一个序列，使orders的id自增长
    create sequence orders_seq
    start with 1
    increment by 1
    minvalue 1
    maxvalue 9999999999
    nocycle
    nocache
    
    -- 用户表
    create table user_(
           id number primary key,
           name varchar2(50) not null,
           pwd varchar2(50) not null,
           email varchar2(100) not null,
           tel varchar2(20) not null,
           grade number(2) default 1 not null
    )
    
    insert into user_ values(100, 'jiaozl', '111', 'jiaozl@qq.com', '110', 1);
    insert into user_ values(101, 'xiaoming', '111', 'xiaoming@qq.com', '120', 1);
    insert into user_ values(102, '小红', '111', 'xiaohong@qq.com', '130', 1);
    
    
    -- 商品表
    create table book(
           id number primary key,
           name varchar2(50) not null,
           author varchar2(50) not null,
           publishHouse varchar2(100) not null,
           price number not null,
           nums number default 1000 not null
    )
    
    insert into book values(book_seq.nextval, 'jsp应用开发详解', '小风', '电子工业出版社', 59, 100);
    insert into book values(book_seq.nextval, 'java web服务开发', '谭美君', '电子工业出版社', 45, 100);
    insert into book values(book_seq.nextval, 'Java编程思想', '小红', '机械工业出版社', 99, 100);
    insert into book values(book_seq.nextval, 'jsp编程指南', '王芳', '电子工业出版社', 19, 1000);
    insert into book values(book_seq.nextval, 'j2ee 1.4应用开发详解', '小贱', '电子工业出版社', 68, 100);
    insert into book values(book_seq.nextval, 'j2ee企业级应用开发', '小菲', '电子工业出版社', 56, 1000);
    insert into book values(book_seq.nextval, 'j2ee参考手册', '小风', '电子工业出版社', 56, 1000);
    insert into book values(book_seq.nextval, 'j2ee web服务开发', '顺平', '电子工业出版社', 550, 100000);
    
    -- 订单表
    -- 设计思路：为了避免数据冗余，我们把公有的信息，抽取出来创建一个单独的表，把不共有的信息，建一张单独表。
    create table orders(
           id number primary key,
           userId number references user_(id),
           totalPrice number default 0 not null,
           orderDate date default sysdate not null
    )
    create table ordersItem(
           id number primary key,
           ordersId number references orders(id),
           bookId number references book(id),
           bookNum number default 0 not null
    )

### 2 创建login、hall、showCart等jsp页面 ###

通过Servlet控制器实现业务化跳转  
![这里写图片描述][SouthEast]![这里写图片描述][SouthEast 1]  
![这里写图片描述][SouthEast 2]

<body>
      <h1>欢迎访问购物大厅</h1>
      <table border="1">
        <tr><th>书名</th><th>价格</th><th>出版社</th><th>点击购买</th></tr>
        <% 
            ArrayList<Book> books = (ArrayList<Book>) request.getAttribute("books"); 
            for(int i =0; i<books.size(); i++ ) {
                Book book = books.get(i);
                %>
                <tr><td><%=book.getName() %></td><td><%=book.getPrice() %></td><td><%=book.getPublishHouse() %></td><td><a href="#">购买</a></td></tr>
                <%
            }
        %>
        <tr><td colspan="4"><input type="button" value="查看购物车" /></td></tr>
      </table>
      <a href="/myshopping">返回重新登录</a>
    </body>

<body>
      <h1>我的购物车</h1>
      <a href="/myshopping/GotoHallUI"> 返回购物大厅    </a>
      <form action="/myshopping/ShoppingClServlet?type=update&" method="post">
       <table border="1" style="border-collapse: collapse; width: 600px; ">
        <tr><th>bookID</th><th>书名</th><th>价格</th><th>出版社</th><th>数量</th><th>删除</th></tr>
        <%
            ArrayList<Book> books = (ArrayList<Book>) request.getAttribute("books");
            for(int i=0; i<books.size(); i++) {
                Book book = books.get(i);
                %>
                <tr>
                    <%-- 提交表单时，获取表格中信息 -->
                    <td><%=book.getId() %><input type="hidden" name="id" value="<%=book.getId() %>" /></td>
                    <td><%=book.getName() %></td>
                    <td><%=book.getPrice() %></td><td><%=book.getPublishHouse() %></td>
                    <td><input type="text" name="booknum" value="<%=book.getShoppingNum() %>" />本</td>
                    <td><a href="/myshopping/ShoppingClServlet?type=del&id=<%=book.getId() %>">删除</a></td>
                </tr>
                <%
            }
         %>
        <tr>
            <td colspan="6"><input type="submit" value="update" ></td>
        </tr>
        <tr>
            <td colspan="6">购物车的总价格:${ totalPrice } 元</td>
        </tr> 
       </table>
      </form>
    </body>

### 3 GotoHallUI 实现login.jsp—->hall.jsp ###

package com.test.controller;
    import java.io.*;
    import javax.servlet.ServletException;
    import javax.servlet.http.*;
    import com.test.domain.Users;
    import com.test.service.UserService;
    public class GotoHallUI extends HttpServlet {
        
        public void doGet(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {
            response.setContentType("text/html; charset=utf-8");
            PrintWriter out = response.getWriter();
            // 取出从登陆页面传递的用户名和密码
            String uid = request.getParameter("uid");
            String p = request.getParameter("passwd");
            Users loginUser = new Users(Integer.parseInt(uid), p);
            UserService userService = new UserService();
            Boolean b = userService.checkUser(loginUser);
            if(b) {
                // 创建购物车
                MyCart mycart = new MyCart();
                // 在哪里都能访问到
                request.getSession().setAttribute("mycart", mycart);
                // 获取书籍信息
                BookService bookService = new BookService();
                ArrayList<com.test.domain.Book> books = bookService.getAllBook();
                request.setAttribute("books", books);
                // 跳转
                request.getRequestDispatcher("WEB-INF/hall.jsp").forward(request, response);;
            } else {
                request.getRequestDispatcher("WEB-INF/login.jsp").forward(request, response);;
            }
        }
        public void doPost(HttpServletRequest request, HttpServletResponse response)
                throws ServletException, IOException {
            this.doGet(request, response);
        }
    }

[SouthEast]: https://img-blog.csdn.net/20170425215119502?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMzk0MzQyMA==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast
[SouthEast 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/3ba243156b1e416f8bc648fd9ed70047.png
[SouthEast 2]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/29/77d9a67da74240a98360ef64ee4baba5.png