利用servlet实现对书籍书名、单价、数量等信息的添加，计算总价

1.题目要求

利用servlet实现对书籍书名、单价、数量等信息的添加，计算总价。

要求：输入两次表单信息，在一个成功返回的页面里面显示两次的数据。

2.Book实体类


package com.hjj.sevletgk.hw7.book;
 
/**
 * @author:嘉佳 Date:2023/10/8 15:16
 **/
 
public class Book {
    private double price;
    private int num;
    private String bookName;
    private double totalPrice;
 
    public Book(){
 
    }
 
    public Book(double price, int num, String bookName) {
        this.price = price;
        this.num = num;
        this.bookName = bookName;
    }
 
    public double getPrice() {
        return price;
    }
 
    public void setPrice(double price) {
        this.price = price;
    }
 
    public int getNum() {
        return num;
    }
 
    public void setNum(int num) {
        this.num = num;
    }
 
    public String getBookName() {
        return bookName;
    }
 
    public void setBookName(String bookName) {
        this.bookName = bookName;
    }
 
    public double getTotalPrice() {
        return this.price*this.num;
    }
 
    public void setTotalPrice(double totalPrice) {
        this.totalPrice = totalPrice;
    }
 
}

3.sevlet


package com.hjj.sevletgk.hw7.booksevlet;
 
import com.hjj.sevletgk.hw7.book.Book;
 
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
 
@WebServlet("/book")
public class BookServlet extends HttpServlet {
    private List bookList=new ArrayList<>();
 
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String bookName=req.getParameter("bookName");
        double price = Double.parseDouble(req.getParameter("price"));
        int num = Integer.parseInt(req.getParameter("num"));
 
        // 把录入的信息添加到列表中
        Book book = new Book(price,num,bookName);
        bookList.add(book);
 
        // 计算总价
        int totalNum=0;
        double totalPrice = 0;
        for (Book b : bookList) {
            totalNum += b.getNum();
            totalPrice += b.getTotalPrice();
        }
 
        req.setAttribute("bookList", bookList);
        req.setAttribute("totalPrice", totalPrice);
        req.setAttribute("totalNum", totalNum);
 
        // 转发到结果页面
        RequestDispatcher dispatcher = req.getRequestDispatcher("hw7/result.jsp");
        dispatcher.forward(req, resp);
    }
}

4.jsp

(1) order.jsp


<%--
  Created by IntelliJ IDEA.
  User: ALASIJIA
  Date: 2023/10/8
  Time: 15:11
  To change this template use File | Settings | File Templates.
--%>
<%@page contentType="text/html;charset=UTF-8"%>
<%@page pageEncoding="UTF-8"%>
<html>
<head>
    <meta charset="UTF-8">
    <title>信息录入</title>
</head>
<body>
<h2>请输入购书信息</h2>
<form method="post" action="${pageContext.request.contextPath}/book" >
    <label for="bookName">书名</label>
    <input type="text" name="bookName" id="bookName"  required><br/>
    <label for="price">单价</label>
    <input type="text" name="price" id="price" required><br/>
    <label for="num">数量</label>
    <input type="text" name="num" id="num" required><br/>
    <input type="submit" value="提交"/>
</form>
</body>
</html>

(2) result.jsp


<%--
  Created by IntelliJ IDEA.
  User: ALASIJIA
  Date: 2023/10/8
  Time: 15:09
  To change this template use File | Settings | File Templates.
--%>
<%@page contentType="text/html;charset=UTF-8" %>
<%@page pageEncoding="UTF-8" %>
<%@page import="com.hjj.sevletgk.hw7.book.Book" %>
<%@ page import="java.util.List" %>
<html>
<head>
    <title>信息查看</title>
    <meta charset="UTF-8">
    <style>
        h2 {
            text-align: center;
        }
 
        table {
            /* 合并边框 */
            border-collapse: collapse;
            height: 80px;
            /* 居中 */
            margin: 0 auto;
        }
 
        th {
            /* 内边距 */
            padding: 5px 20px;
        }
 
        table, th, td {
            border: 1px solid #000;
        }
    </style>
</head>
<body>
<%--
id：指定实例化的 JavaBean 对象的名称
class：指定要实例化的 JavaBean 对象的类的全类名
--%>
<jsp:useBean id="Book" class="com.hjj.sevletgk.hw7.book.Book"/>
<jsp:setProperty name="Book" property="*"/>
<h2>商品总价</h2>
<%
    request.setCharacterEncoding("UTF-8");
%>
 
    <table>
        <tr>
            <th>书名</th>
            <th>价格</th>
            <th>数量</th>
            <th>总价</th>
        </tr>
        <% for (Book book : (List<Book>) request.getAttribute("bookList")) { %>
        <tr>
            <td><%= book.getBookName() %></td>
            <td><%= book.getPrice() %></td>
            <td><%= book.getNum() %></td>
            <td><%= book.getTotalPrice() %></td>
        </tr>
        <% } %>
        <tr>
            <%--        该单元格要横跨 2 列--%>
            <td colspan="2"><b>总计:</b></td>
            <td><b>商品总数:</b><%= request.getAttribute("totalNum") %></td>
            <td><b>总价:</b><%= request.getAttribute("totalPrice") %></td>
        </tr>
    </table>
</body>
</html>

相关阅读:
Vue.js 3.x 响应式系统原理
 翻译QT使用手册：将库添加到项目
 剑指 Offer 17. 打印从1到最大的n位数（大数问题）
【排序算法】冒泡排序
 python中的GUI自动化工具介绍
 3.你所不知道的go语言控制语句——Leetcode习题69
ARC147E Examination
SpringCloud 微服务全栈体系（三）
springboot+vue实现excel的导出
 java计算机毕业设计高校疫情管理源码+数据库+系统+lw文档+mybatis+运行部署
原文地址：https://blog.csdn.net/GANTENJ/article/details/134301244