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<Book> 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>
