书城项目第六、七阶段

1. 项目第六阶段：购物车

页面样式

购物车

书城项目第六、七阶段_书城

我的订单

书城项目第六、七阶段_javaweb_02

结算

书城项目第六、七阶段_java_03

1.1 购物车模块分析

书城项目第六、七阶段_书城_04

1.2、购物车实现

1.2.1 购物车模型

1.2.2 购物车的测试

创建 pojo/CartItem
package com.atguigu.pojo;

import java.math.BigDecimal;

/**
 * 购物车的商品相
 */
public class CartItem {
    private Integer id;
    private String name;
    private Integer count;
    private BigDecimal Price;
    private BigDecimal totalPrice;

    public CartItem() {
    }

    public CartItem(Integer id, String name, Integer count, BigDecimal price, BigDecimal totalPrice) {
        this.id = id;
        this.name = name;
        this.count = count;
        Price = price;
        this.totalPrice = totalPrice;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public BigDecimal getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }

    public BigDecimal getPrice() {
        return Price;
    }

    public void setPrice(BigDecimal price) {
        Price = price;
    }

    @Override
    public String toString() {
        return "CartIem{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", count=" + count +
                ", totalPrice=" + totalPrice +
                '}';
    }
}
创建 pojo/Cart
package com.atguigu.pojo;

import java.math.BigDecimal;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * 购物车对象
 */
public class Cart {
//    private Integer totalCount;
//    private BigDecimal totalPrice;
    /**
     * key是商品编号
     * value是商品信息
     */
    private Map<Integer,CartItem> items=new LinkedHashMap<>();

    /**
     * 添加商品项
     * @param cartItem
     */
    public void addItem(CartItem cartItem){
        //Crtl+Shift+T
        // 先查看购物车中是否添加过此商品，如果已添加，则数量累加，总金额更新，如果，没有添加过，直接放入集合中即可
        CartItem item = items.get(cartItem.getId());
        if (item==null){
            //之前没添加
            items.put(cartItem.getId(),cartItem);
        }else {
            //已添加
            item.setCount(item.getCount()+1);//数量累加
            item.setTotalPrice(cartItem.getPrice().multiply(new BigDecimal(item.getCount())));//总金额更新
        }
    }

    /*
     * 删除商品项
     */
    public void deleteItem(Integer id){
        items.remove(id);
    }

    /*
     * 清空购物车
     */
    public void clear(){
        items.clear();
    }

    /*
     * 修改商品数量
     */
    public void updateCount(Integer id,Integer count){
        //先查看购物车中是否有次商品。如果有，则修改数量，更新总金额
        CartItem cartItem = items.get(id);
        if (cartItem!=null){
            cartItem.setCount(count);//修改数量
            cartItem.setTotalPrice(cartItem.getPrice().multiply(new BigDecimal(cartItem.getCount())));//总金额更新
        }
    }

    public Integer getTotalCount() {
        Integer totalCount=0;
        for (Map.Entry<Integer,CartItem> entry:items.entrySet()) {
            totalCount+=entry.getValue().getCount();
        }
        return totalCount;
    }

//    public void setTotalCount(Integer totalCount) {
//        this.totalCount = totalCount;
//    }

    public BigDecimal getTotalPrice() {
        BigDecimal totalPrice =new BigDecimal(0);
        for (Map.Entry<Integer,CartItem> entry:items.entrySet()) {
            totalPrice=totalPrice.add(entry.getValue().getTotalPrice());
        }
        return totalPrice;
    }

//    public void setTotalPrice(BigDecimal totalPrice) {
//        this.totalPrice = totalPrice;
//    }

    public Map<Integer, CartItem> getItems() {
        return items;
    }

    public void setItems(Map<Integer, CartItem> items) {
        this.items = items;
    }

    @Override
    public String toString() {
        return "Cart{" +
                "totalCount=" + getTotalCount() +
                ", totalPrice=" + getTotalPrice() +
                ", items=" + items +
                '}';
    }
}
测试 创建 test/CartTest
package com.atguigu.test;

import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import org.junit.Test;

import java.math.BigDecimal;


public class CartTest {

    @Test
    public void addItem() {
        Cart cart=new Cart();
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(2,"数据结构与算法",1,new BigDecimal(100),new BigDecimal(100)));

        System.out.println(cart);
    }

    @Test
    public void deleteItem() {
        Cart cart=new Cart();
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(2,"数据结构与算法",1,new BigDecimal(100),new BigDecimal(100)));

        cart.deleteItem(1);

        System.out.println(cart);


    }

    @Test
    public void clear() {
        Cart cart=new Cart();
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(2,"数据结构与算法",1,new BigDecimal(100),new BigDecimal(100)));

        cart.deleteItem(1);

        cart.clear();

        System.out.println(cart);
    }

    @Test
    public void updateCount() {
        Cart cart=new Cart();
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(2,"数据结构与算法",1,new BigDecimal(100),new BigDecimal(100)));

        cart.deleteItem(1);

        cart.clear();

        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.updateCount(1,10);

        System.out.println(cart);
    }
}

1.3、加入购物车功能的实现

书城项目第六、七阶段_书城_05

创建 CartServlet，并配置web.xml

package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CartServlet extends BaseServlet{
    private BookService bookService=new BookServiceImpl();
    /**
     * 加入购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//        System.out.println("加入购物车");
//        System.out.println("商品编号："+req.getParameter("id"));

        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);
        //调用bookService.queryBookById(id):Book 得到图书的信息
        Book book=bookService.queryBookById(id);
        //把图书信息，转换成为CartItem商品项
        CartItem cartItem=new CartItem(book.getId(), book.getName(), 1,book.getPrice(),book.getPrice());
        //调用Cart.addItem(CartItem):添加商品项
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart==null){
            cart=new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
        System.out.println(cart);


        //重定向回商品列表页面
//        resp.sendRedirect(req.getContextPath());

//        System.out.println("请求头Referer的值："+req.getHeader("Referer"));

        //重定向回原来商品所在地址页面
        resp.sendRedirect(req.getHeader("Referer"));

    }
}

修改 index.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>书城首页</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">
        $(function (){
            //给加入购物车按钮绑定单击事件
            $("button.addToCart").click(function (){
                /**
                 * 在事件响应的function函数中，有一个this对象，这个this对象，是当前正在响应事件的dom对象
                 * @type {*|jQuery}
                 */
                var bookId= $(this).attr("bookId");
                location.href="http://localhost:8080/book/cartServlet?action=addItem&id="+bookId;
            });
        });

    </script>

</head>
<body>

    <div id="header">

        <img class="logo_ing"  alt=""  src="static/img/logo.gif">
        <span class= "wel_word">网上书城</span>
        <div>
            <%--  如果用户还没有登录，显示【登录和注册的菜单】--%>
            <c:if test="${empty sessionScope.user}">
                <a href="pages/user/login.jsp">登录</a>
                <a href="pages/user/regist.jsp">注册</a>
            </c:if>
            <%--  如果已经登录，显示登录之后的用户信息--%>
            <c:if test="${not empty sessionScope.user}">
                <span>欢迎<span class="um_span">${sessionScope.user.username}</span>光临尚硅谷书城</span>
                <a href="pages/order/order.jsp">我的订单</a>
                <a href="userServlet?action=logout">注销</a>
            </c:if>

            <a href="pages/cart/cart.jsp">购物车</a>
            <a href="pages/manager/manager.jsp">后台管理</a>
        </div>

        <div id="main">
            <div id="book">
                <div class="book_cond">
                    <form action="client/bookServlet" method="get">
                    <input type="hidden" name="action" value="pageByPrice">
                    价格:<input id="min" type="text"  name="min" value="${param.min}">元 -
                        <input id="max" type="text" name="max" value="${param.max}">元
                        <input type="submit" value="查询"/>
                    </form>
                </div>
                <div style="...">
                    <span>您的购物车中有3件商品</span>
                    <div>
                        您刚刚将<span style="...">时间简史</span>加入到了购物车中
                    </div>
                </div>


                <div>
                <c:forEach items="${requestScope.page.items}" var="book">
                    <div class="b_list">
                        <div class="img_div">
                            <img class="book_img" alt="${book.imgPath}"/>
                        </div>
                        <div class="book_info">
                            <div class="book_name">
                                <span class="sp1">书名:</span>
                                <span class="sp2">${book.name}</span>
                            </div>
                            <div class="book_author">
                                <span class="sp1">作者:</span>
                                <span class="sp2">${book.author}</span>
                            </div>
                            <div class= "book_price">
                                <span class="sp1">价格:</span>
                                <span class="sp2">￥${book.price}</span>
                            </div>
                            <div class="book_sales">
                                <span class="sp1">销量:</span>
                                <span class="sp2">${book.sales}</span>
                            </div>
                            <div class="book_amount">
                                <span class="sp1">库存:</span>
                                <span class="sp2">${book.stock}</span>
                            </div>
                            <div class="book_add">
                                <button bookId="${book.id}" class="addToCart">加入购物车:</button>
                        </div>
                        </div>
                    </div>
                </c:forEach>
                </div>
            </div>

            <%-- 静态包含分页条    --%>
          <%@include file="/pages/common/page_nav.jsp"%>


        </div>

    </div>

    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>


</body>
</html>

1.4 购物车的展示

修改 cart.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>购物车</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>


</head>
<body>

    <div id="header">
        <img class="logo_img" alt="" src="static/img/logo.gif">
        <span class="wel_word">购物车</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
        <table>
            <tr>
                <td>商品名称</td>
                <td>数量</td>
                <td>单价</td>
                <td>金额</td>
                <td>操作</td>
            </tr>
            <c:if test="${empty sessionScope.cart.items}">
            <%--  如果购物车为空的情况   --%>
                <td colspan="5"><a href="index.jsp"> 亲，当前购物车为空！快跟小伙伴们去浏览商品吧！！！</a></td>
            </c:if>

            <c:if test="${not empty sessionScope.cart.items}">
            <%--  如果购物车非空的情况   --%>
                <c:forEach items="${sessionScope.cart.items}" var="entry">
                    <tr>
                        <td>${entry.value.name}</td>
                        <td>${entry.value.count}</td>
                        <td>${entry.value.price}</td>
                        <td>${entry.value.totalPrice}</td>
                        <td><a href="#">删除</a></td>
                    </tr>
                </c:forEach>

            </c:if>
        </table>
        <c:if test="${not empty sessionScope.cart.items}">
            <div class="cart_info">
                <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
                <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
                <span class="cart_span"><a href="#">清空购物车</a></span>
                <span class="cart span"><a href="pages/cart/checkout.jsp">去结账</a></span>
            </div>
        </c:if>
    </div>



    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

1.5 删除购物车的商品项

修改 CartServlet

package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CartServlet extends BaseServlet{
    private BookService bookService=new BookServiceImpl();
    /**
     * 加入购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//        System.out.println("加入购物车");
//        System.out.println("商品编号："+req.getParameter("id"));

        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);
        //调用bookService.queryBookById(id):Book 得到图书的信息
        Book book=bookService.queryBookById(id);
        //把图书信息，转换成为CartItem商品项
        CartItem cartItem=new CartItem(book.getId(), book.getName(), 1,book.getPrice(),book.getPrice());
        //调用Cart.addItem(CartItem):添加商品项
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart==null){
            cart=new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
        System.out.println(cart);


        //重定向回商品列表页面
//        resp.sendRedirect(req.getContextPath());

//        System.out.println("请求头Referer的值："+req.getHeader("Referer"));

        //重定向回原来商品所在地址页面
        resp.sendRedirect(req.getHeader("Referer"));

    }

    /**
     * 删除商品项
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {


        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);

        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //删除了购物车商品项
            cart.deleteItem(id);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }



    }
}

修改 cart.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>购物车</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">$(function (){
            //给删除绑定单击事件
            $("a.deleteItem").click(function (){
                return confirm("你确定要删除吗【"+$(this).parent().parent().find("td:first").text()+"】？");
            });
        });</script>

</head>
<body>

    <div id="header">
        <img class="logo_img" alt="" src="static/img/logo.gif">
        <span class="wel_word">购物车</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
        <table>
            <tr>
                <td>商品名称</td>
                <td>数量</td>
                <td>单价</td>
                <td>金额</td>
                <td>操作</td>
            </tr>
            <c:if test="${empty sessionScope.cart.items}">
            <%--  如果购物车为空的情况   --%>
                <td colspan="5"><a href="index.jsp"> 亲，当前购物车为空！快跟小伙伴们去浏览商品吧！！！</a></td>
            </c:if>

            <c:if test="${not empty sessionScope.cart.items}">
            <%--  如果购物车非空的情况   --%>
                <c:forEach items="${sessionScope.cart.items}" var="entry">
                    <tr>
                        <td>${entry.value.name}</td>
                        <td>${entry.value.count}</td>
                        <td>${entry.value.price}</td>
                        <td>${entry.value.totalPrice}</td>
                        <td><a class="deleteItem" href="cartServlet?action=deleteItem&id=${entry.value.id}">删除</a></td>
                    </tr>
                </c:forEach>

            </c:if>
        </table>
        <c:if test="${not empty sessionScope.cart.items}">
            <div class="cart_info">
                <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
                <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
                <span class="cart_span"><a href="#">清空购物车</a></span>
                <span class="cart span"><a href="pages/cart/checkout.jsp">去结账</a></span>
            </div>
        </c:if>
    </div>



    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

1.6 清空购物车

修改 CartServlet

package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CartServlet extends BaseServlet{
    private BookService bookService=new BookServiceImpl();
    /**
     * 加入购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//        System.out.println("加入购物车");
//        System.out.println("商品编号："+req.getParameter("id"));

        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);
        //调用bookService.queryBookById(id):Book 得到图书的信息
        Book book=bookService.queryBookById(id);
        //把图书信息，转换成为CartItem商品项
        CartItem cartItem=new CartItem(book.getId(), book.getName(), 1,book.getPrice(),book.getPrice());
        //调用Cart.addItem(CartItem):添加商品项
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart==null){
            cart=new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
//        System.out.println(cart);


        //重定向回商品列表页面
//        resp.sendRedirect(req.getContextPath());

//        System.out.println("请求头Referer的值："+req.getHeader("Referer"));

        //重定向回原来商品所在地址页面
        resp.sendRedirect(req.getHeader("Referer"));

    }

    /**
     * 删除商品项
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {


        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);

        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //删除了购物车商品项
            cart.deleteItem(id);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }



    }

    /**
     * 清空购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void clear(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //清空购物车
            cart.clear();
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }



    }
}

修改 cart.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>购物车</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">$(function (){
            //给删除绑定单击事件
            $("a.deleteItem").click(function (){
                return confirm("你确定要删除吗【"+$(this).parent().parent().find("td:first").text()+"】？");
            });

            //给清空购物车绑定单击事件
            $("#clearCart").click(function (){
                return confirm("你确定要清空购物车吗？");
            });
        });</script>

</head>
<body>

    <div id="header">
        <img class="logo_img" alt="" src="static/img/logo.gif">
        <span class="wel_word">购物车</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
        <table>
            <tr>
                <td>商品名称</td>
                <td>数量</td>
                <td>单价</td>
                <td>金额</td>
                <td>操作</td>
            </tr>
            <c:if test="${empty sessionScope.cart.items}">
            <%--  如果购物车为空的情况   --%>
                <td colspan="5"><a href="index.jsp"> 亲，当前购物车为空！快跟小伙伴们去浏览商品吧！！！</a></td>
            </c:if>

            <c:if test="${not empty sessionScope.cart.items}">
            <%--  如果购物车非空的情况   --%>
                <c:forEach items="${sessionScope.cart.items}" var="entry">
                    <tr>
                        <td>${entry.value.name}</td>
                        <td>${entry.value.count}</td>
                        <td>${entry.value.price}</td>
                        <td>${entry.value.totalPrice}</td>
                        <td><a class="deleteItem" href="cartServlet?action=deleteItem&id=${entry.value.id}">删除</a></td>
                    </tr>
                </c:forEach>

            </c:if>
        </table>
        <c:if test="${not empty sessionScope.cart.items}">
            <div class="cart_info">
                <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
                <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
                <span class="cart_span"><a id="clearCart" href="cartServlet?action=clear">清空购物车</a></span>
                <span class="cart span"><a href="pages/cart/checkout.jsp">去结账</a></span>
            </div>
        </c:if>
    </div>



    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

1.7、修改购物车商品数量

书城项目第六、七阶段_书城_06

修改 CartServlet

package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CartServlet extends BaseServlet{
    private BookService bookService=new BookServiceImpl();
    /**
     * 加入购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//        System.out.println("加入购物车");
//        System.out.println("商品编号："+req.getParameter("id"));

        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);
        //调用bookService.queryBookById(id):Book 得到图书的信息
        Book book=bookService.queryBookById(id);
        //把图书信息，转换成为CartItem商品项
        CartItem cartItem=new CartItem(book.getId(), book.getName(), 1,book.getPrice(),book.getPrice());
        //调用Cart.addItem(CartItem):添加商品项
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart==null){
            cart=new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
//        System.out.println(cart);


        //重定向回商品列表页面
//        resp.sendRedirect(req.getContextPath());

//        System.out.println("请求头Referer的值："+req.getHeader("Referer"));

        //重定向回原来商品所在地址页面
        resp.sendRedirect(req.getHeader("Referer"));

    }

    /**
     * 删除商品项
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {


        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);

        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //删除了购物车商品项
            cart.deleteItem(id);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }



    }

    /**
     * 清空购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void clear(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //清空购物车
            cart.clear();
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }

    }

    /**
     * 修改商品数量
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void updateCount(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取请求的参数 商品编号 ，商品数量
        int id=WebUtils.parseInt(req.getParameter("id"),0);
        int count=WebUtils.parseInt(req.getParameter("count"),1);
        //获取Cart购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //修改商品数量
            cart.updateCount(id,count);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }

    }
}

修改 cart.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>购物车</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">$(function (){
            //给删除绑定单击事件
            $("a.deleteItem").click(function (){
                return confirm("你确定要删除吗【"+$(this).parent().parent().find("td:first").text()+"】？");
            });

            //给清空购物车绑定单击事件
            $("#clearCart").click(function (){
                return confirm("你确定要清空购物车吗？");
            });
            //给输入框失去焦点事件 === onchange 内容发生改变事件
            $(".updateCount").change(function (){
                //获取商品名称
                var name=$(this).parent().parent().find("td:first").text();
                //获取商品id
                var id=$(this).attr("bookId");
                //获取商品数量
                var count=this.value;
                if (confirm("你确定要将【"+name+"】商品修改数量为："+count+"吗？")){
                    //发起请求。给服务器保存修改
                    location.href="http://localhost:8080/book/cartServlet?action=updateCount&count="+count+"&id="+id;
                }else {
                    //defaultValue属性是表单项Dom对象的属性。它表示默认的value属性值。
                    this.value=this.defaultValue;
                }

            });
        });</script>

</head>
<body>

    <div id="header">
        <img class="logo_img" alt="" src="static/img/logo.gif">
        <span class="wel_word">购物车</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
        <table>
            <tr>
                <td>商品名称</td>
                <td>数量</td>
                <td>单价</td>
                <td>金额</td>
                <td>操作</td>
            </tr>
            <c:if test="${empty sessionScope.cart.items}">
            <%--  如果购物车为空的情况   --%>
                <td colspan="5"><a href="index.jsp"> 亲，当前购物车为空！快跟小伙伴们去浏览商品吧！！！</a></td>
            </c:if>

            <c:if test="${not empty sessionScope.cart.items}">
            <%--  如果购物车非空的情况   --%>
                <c:forEach items="${sessionScope.cart.items}" var="entry">
                    <tr>
                        <td>${entry.value.name}</td>
                        <td>
                            <input class="updateCount" style="width:"
                                   bookId="${entry.value.id}"
                                   type="text" value="${entry.value.count}">
                        </td>
                        <td>${entry.value.price}</td>
                        <td>${entry.value.totalPrice}</td>
                        <td><a class="deleteItem" href="cartServlet?action=deleteItem&id=${entry.value.id}">删除</a></td>
                    </tr>
                </c:forEach>

            </c:if>
        </table>
        <c:if test="${not empty sessionScope.cart.items}">
            <div class="cart_info">
                <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
                <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
                <span class="cart_span"><a id="clearCart" href="cartServlet?action=clear">清空购物车</a></span>
                <span class="cart span"><a href="pages/cart/checkout.jsp">去结账</a></span>
            </div>
        </c:if>
    </div>



    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

1.8、首页，购物车回显

修改 CartServlet

package com.atguigu.web;

import com.atguigu.pojo.Book;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.BookService;
import com.atguigu.service.impl.BookServiceImpl;
import com.atguigu.utils.WebUtils;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CartServlet extends BaseServlet{
    private BookService bookService=new BookServiceImpl();
    /**
     * 加入购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void addItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

//        System.out.println("加入购物车");
//        System.out.println("商品编号："+req.getParameter("id"));

        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);
        //调用bookService.queryBookById(id):Book 得到图书的信息
        Book book=bookService.queryBookById(id);
        //把图书信息，转换成为CartItem商品项
        CartItem cartItem=new CartItem(book.getId(), book.getName(), 1,book.getPrice(),book.getPrice());
        //调用Cart.addItem(CartItem):添加商品项
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart==null){
            cart=new Cart();
            req.getSession().setAttribute("cart",cart);
        }
        cart.addItem(cartItem);
//        System.out.println(cart);


        //重定向回商品列表页面
//        resp.sendRedirect(req.getContextPath());

//        System.out.println("请求头Referer的值："+req.getHeader("Referer"));

        //最后一个添加商品的名称
        req.getSession().setAttribute("lastName",cartItem.getName());

        //重定向回原来商品所在地址页面
        resp.sendRedirect(req.getHeader("Referer"));

    }

    /**
     * 删除商品项
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void deleteItem(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {


        //获取请求的参数 商品编号
        int id= WebUtils.parseInt(req.getParameter("id"),0);

        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //删除了购物车商品项
            cart.deleteItem(id);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }



    }

    /**
     * 清空购物车
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void clear(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //清空购物车
            cart.clear();
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }

    }

    /**
     * 修改商品数量
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void updateCount(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取请求的参数 商品编号 ，商品数量
        int id=WebUtils.parseInt(req.getParameter("id"),0);
        int count=WebUtils.parseInt(req.getParameter("count"),1);
        //获取Cart购物车对象
        Cart cart= (Cart) req.getSession().getAttribute("cart");
        if (cart!=null){
            //修改商品数量
            cart.updateCount(id,count);
            //重定向回原来商品所在地址页面
            resp.sendRedirect(req.getHeader("Referer"));
        }

    }
}

修改 index.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>书城首页</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">
        $(function (){
            //给加入购物车按钮绑定单击事件
            $("button.addToCart").click(function (){
                /**
                 * 在事件响应的function函数中，有一个this对象，这个this对象，是当前正在响应事件的dom对象
                 * @type {*|jQuery}
                 */
                var bookId= $(this).attr("bookId");
                location.href="http://localhost:8080/book/cartServlet?action=addItem&id="+bookId;
            });
        });

    </script>

</head>
<body>

    <div id="header">

        <img class="logo_ing"  alt=""  src="static/img/logo.gif">
        <span class= "wel_word">网上书城</span>
        <div>
            <%--  如果用户还没有登录，显示【登录和注册的菜单】--%>
            <c:if test="${empty sessionScope.user}">
                <a href="pages/user/login.jsp">登录</a>
                <a href="pages/user/regist.jsp">注册</a>
            </c:if>
            <%--  如果已经登录，显示登录之后的用户信息--%>
            <c:if test="${not empty sessionScope.user}">
                <span>欢迎<span class="um_span">${sessionScope.user.username}</span>光临尚硅谷书城</span>
                <a href="pages/order/order.jsp">我的订单</a>
                <a href="userServlet?action=logout">注销</a>
            </c:if>

            <a href="pages/cart/cart.jsp">购物车</a>
            <a href="pages/manager/manager.jsp">后台管理</a>
        </div>

        <div id="main">
            <div id="book">
                <div class="book_cond">
                    <form action="client/bookServlet" method="get">
                    <input type="hidden" name="action" value="pageByPrice">
                    价格:<input id="min" type="text"  name="min" value="${param.min}">元 -
                        <input id="max" type="text" name="max" value="${param.max}">元
                        <input type="submit" value="查询"/>
                    </form>
                </div>

                <div style="...">
                    <c:if test="${empty sessionScope.cart.items}">
                        <%-- 购物车为空的输出  --%>
                        <span></span>
                        <div>
                            <span style="...">当前购物车为空</span>
                        </div>
                    </c:if>
                    <c:if test="${not empty sessionScope.cart.items}">
                        <%-- 购物车非空的输出  --%>
                        <span>您的购物车中有${sessionScope.cart.totalCount}件商品</span>
                        <div>
                            您刚刚将<span style="...">${sessionScope.lastName}</span>加入到了购物车中
                        </div>
                    </c:if>

                </div>


                <div>
                <c:forEach items="${requestScope.page.items}" var="book">
                    <div class="b_list">
                        <div class="img_div">
                            <img class="book_img" alt="${book.imgPath}"/>
                        </div>
                        <div class="book_info">
                            <div class="book_name">
                                <span class="sp1">书名:</span>
                                <span class="sp2">${book.name}</span>
                            </div>
                            <div class="book_author">
                                <span class="sp1">作者:</span>
                                <span class="sp2">${book.author}</span>
                            </div>
                            <div class= "book_price">
                                <span class="sp1">价格:</span>
                                <span class="sp2">￥${book.price}</span>
                            </div>
                            <div class="book_sales">
                                <span class="sp1">销量:</span>
                                <span class="sp2">${book.sales}</span>
                            </div>
                            <div class="book_amount">
                                <span class="sp1">库存:</span>
                                <span class="sp2">${book.stock}</span>
                            </div>
                            <div class="book_add">
                                <button bookId="${book.id}" class="addToCart">加入购物车:</button>
                        </div>
                        </div>
                    </div>
                </c:forEach>
                </div>
            </div>

            <%-- 静态包含分页条    --%>
          <%@include file="/pages/common/page_nav.jsp"%>


        </div>

    </div>

    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>


</body>
</html>

2、项目第七阶段：订单模块

2.1、订单模块的分析

现在只实现“生成订单”功能

书城项目第六、七阶段_html_07

2.2、订单模块的实现

2.2.1、创建订单模块的数据库表

create table t_order
  order_id varchar (50) primary key,
  create_time datetime.
  price decimal(11,2)，
  status int,
  user id int,
  foreign key(user_id)  references t_user (id)  
);
create table t_order_item(
  id int primary key auto_increment
  name varchar (100)
  count  int,
  price decimal(11,2)
  total price decimal (11,2)
  order_id varchar (50)
  foreign key (order_id) references t_order (order_id)  
);

书城项目第六、七阶段_数据结构_08

2.2.2、创建订单模块的数据模型

创建 pojo/Order

package com.atguigu.pojo;

import java.math.BigDecimal;
import java.util.Date;

public class Order {
    private String orderId;
    private Date createTime;
    private BigDecimal price;
    //0未发货，1已发货，2已签收
    private Integer status=0;
    private Integer userId;

    public Order() {
    }

    public Order(String orderId, Date createTime, BigDecimal price, Integer status, Integer userId) {
        this.orderId = orderId;
        this.createTime = createTime;
        this.price = price;
        this.status = status;
        this.userId = userId;
    }

    public String getOrderId() {
        return orderId;
    }

    public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public Integer getStatus() {
        return status;
    }

    public void setStatus(Integer status) {
        this.status = status;
    }

    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    @Override
    public String toString() {
        return "Order{" +
                "orderId='" + orderId + '\'' +
                ", createTime=" + createTime +
                ", price=" + price +
                ", status=" + status +
                ", userId=" + userId +
                '}';
    }
}

创建pojo/OrderItem

package com.atguigu.pojo;


import java.math.BigDecimal;

public class OrderItem {
    private Integer id;
    private String name;
    private Integer count;
    private BigDecimal price;
    private BigDecimal totalPrice;
    private String orderId;

    public OrderItem() {
    }

    public OrderItem(Integer id, String name, Integer count, BigDecimal price, BigDecimal totalPrice, String orderId) {
        this.id = id;
        this.name = name;
        this.count = count;
        this.price = price;
        this.totalPrice = totalPrice;
        this.orderId = orderId;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public BigDecimal getPrice() {
        return price;
    }

    public void setPrice(BigDecimal price) {
        this.price = price;
    }

    public BigDecimal getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(BigDecimal totalPrice) {
        this.totalPrice = totalPrice;
    }

    public String getOrderId() {
        return orderId;
    }

    public void setOrderId(String orderId) {
        this.orderId = orderId;
    }

    @Override
    public String toString() {
        return "OrderItem{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", count=" + count +
                ", price=" + price +
                ", totalPrice=" + totalPrice +
                ", orderId='" + orderId + '\'' +
                '}';
    }
}

2.2.3、编写订单模块的Dao程序和测试

创建dao/OrderDao

package com.atguigu.dao;

import com.atguigu.pojo.Order;

public interface OrderDao {

    public int saveOrder(Order order);
}

创建 impl/OrderDaoImpl

package com.atguigu.dao.impl;

import com.atguigu.dao.OrderDao;
import com.atguigu.pojo.Order;

public class OrderDaoImpl extends BaseDao implements OrderDao {


    @Override
    public int saveOrder(Order order) {
        String sql="insert into t_order(order_id,create_time,price,status,user_id)values(?,?,?,?,?)";
        return update(sql,order.getOrderId(),order.getCreateTime(),order.getPrice(),order.getStatus(),order.getOrderId());
    }
}

创建dao/OrderItemDao

package com.atguigu.dao;

import com.atguigu.pojo.OrderItem;

public interface OrderItemDao {
    public int saveOrderItem(OrderItem orderItem);

}

创建impl/OrderItemDaoImpl

package com.atguigu.dao.impl;

import com.atguigu.dao.OrderItemDao;
import com.atguigu.pojo.OrderItem;

public class OrderItemDaoImpl extends BaseDao implements OrderItemDao {

    @Override
    public int saveOrderItem(OrderItem orderItem) {
        String sql="insert into t_order_item(name,count,price,total_price,order_id)values(?,?,?,?,?)";
        return update(sql,orderItem.getName(),orderItem.getCount(),orderItem.getPrice(),orderItem.getTotalPrice(),orderItem.getUserId());
    }
}

测试 test/OrderDaoTest

package com.atguigu.test;

import com.atguigu.dao.OrderDao;
import com.atguigu.dao.impl.OrderDaoImpl;
import com.atguigu.pojo.Order;
import org.junit.Test;

import java.math.BigDecimal;
import java.util.Date;

public class OrderDaoTest {
    @Test
    public void saveOrder() {
        OrderDao orderDao=new OrderDaoImpl();
        orderDao.saveOrder(new Order("1234567890",new Date(),new BigDecimal(100),0,1));
    }
}

创建test/OrderItemDaoTest

package com.atguigu.test;

import com.atguigu.dao.OrderItemDao;
import com.atguigu.dao.impl.OrderItemDaoImpl;
import com.atguigu.pojo.OrderItem;
import org.junit.Test;

import java.math.BigDecimal;

import static org.junit.Assert.*;

public class OrderItemDaoTest {

    @Test
    public void saveOrderItem() {
        OrderItemDao orderItemDao=new OrderItemDaoImpl();
        orderItemDao.saveOrderItem(new OrderItem(null,"java",1,new BigDecimal(100),new BigDecimal(100),"1234657890"));
        orderItemDao.saveOrderItem(new OrderItem(null,"js",2,new BigDecimal(100),new BigDecimal(200),"1234657890"));
        orderItemDao.saveOrderItem(new OrderItem(null,"Netty",1,new BigDecimal(100),new BigDecimal(100),"1234657890"));
    }
}

2.2.4、编写订单模块的Service和测试

创建service/OrderService

package com.atguigu.service;

import com.atguigu.pojo.Cart;

public interface OrderService {
    public String createOrder(Cart cart,Integer userId);

}

创建impl/OrderServiceImpl

package com.atguigu.service.impl;

import com.atguigu.dao.OrderDao;
import com.atguigu.dao.OrderItemDao;
import com.atguigu.dao.impl.OrderDaoImpl;
import com.atguigu.dao.impl.OrderItemDaoImpl;
import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.pojo.Order;
import com.atguigu.pojo.OrderItem;
import com.atguigu.service.OrderService;

import java.util.Date;
import java.util.Map;

public class OrderServiceImpl implements OrderService {
    private OrderDao orderDao =new OrderDaoImpl();
    private OrderItemDao orderItemDao=new OrderItemDaoImpl();

    @Override
    public String createOrder(Cart cart, Integer userId) {
        //订单号==唯一性
        String orderId=System.currentTimeMillis()+""+userId;
        //创建一个订单对象
        Order order=new Order(orderId,new Date(),cart.getTotalPrice(),0,userId);
        //保存订单
        orderDao.saveOrder(order);

        //遍历购物车中每一个商品项转换为订单保存到数据库
        for (Map.Entry<Integer, CartItem>entry:cart.getItems().entrySet()) {
            //获取购物车每一个商品项
            CartItem cartItem=entry.getValue();
            //转换为订单
            OrderItem orderItem=new OrderItem(null,cartItem.getName(),cartItem.getCount(),cartItem.getPrice(),cartItem.getTotalPrice(),orderId);
            //保存到数据库
            orderItemDao.saveOrderItem(orderItem);
        }
        //清空购物车
        cart.clear();

        return orderId;
    }
}

测试 test/OrderServiceTest

package com.atguigu.test;

import com.atguigu.pojo.Cart;
import com.atguigu.pojo.CartItem;
import com.atguigu.service.OrderService;
import com.atguigu.service.impl.OrderServiceImpl;
import org.junit.Test;

import java.math.BigDecimal;

import static org.junit.Assert.*;

public class OrderServiceTest {

    @Test
    public void createOrder() {
        Cart cart=new Cart();
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(1,"java",1,new BigDecimal(1000),new BigDecimal(1000)));
        cart.addItem(new CartItem(2,"数据结构与算法",1,new BigDecimal(100),new BigDecimal(100)));

        OrderService orderService=new OrderServiceImpl();

        System.out.println("订单号是："+orderService.createOrder(cart, 1));
    }
}

2.2.5 结账功能的实现

创建 web/OrderServlet

package com.atguigu.web;

import com.atguigu.pojo.Cart;
import com.atguigu.pojo.User;
import com.atguigu.service.OrderService;
import com.atguigu.service.impl.OrderServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class OrderServlet extends BaseServlet{

    private OrderService orderService=new OrderServiceImpl();

    /**
     * 生成订单
     * @param req
     * @param resp
     * @throws ServletException
     * @throws IOException
     */
    protected void createOrder(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //先获取Cart购物车对象
        Cart cart = (Cart) req.getSession().getAttribute("cart");  //获取Userid
        User loginUser = (User) req.getSession().getAttribute("user");
        if (loginUser==null){
            req.getRequestDispatcher("/pages/user/login.jsp").forward(req,resp);
            return;
        }
        Integer userId = loginUser.getId();
        //调用orderservice.createorder(cart,userid);生成订单
        String orderId = orderService.createOrder(cart, userId);

//        req.setAttribute("orderId",orderId);
        //请求转发至pages/cart/checkout.jsp
//        req.getRequestDispatcher("/pages/cart/checkout.jsp").forward(req,resp);

        req.getSession().setAttribute("orderId",orderId);
        resp.sendRedirect(req.getContextPath()+"/pages/cart/checkout.jsp");
    }
}

修改 cart.jsp

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%--
  Created by IntelliJ IDEA.
  User: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>购物车</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>
    <script type="text/javascript">$(function (){
            //给删除绑定单击事件
            $("a.deleteItem").click(function (){
                return confirm("你确定要删除吗【"+$(this).parent().parent().find("td:first").text()+"】？");
            });

            //给清空购物车绑定单击事件
            $("#clearCart").click(function (){
                return confirm("你确定要清空购物车吗？");
            });
            //给输入框失去焦点事件 === onchange 内容发生改变事件
            $(".updateCount").change(function (){
                //获取商品名称
                var name=$(this).parent().parent().find("td:first").text();
                //获取商品id
                var id=$(this).attr("bookId");
                //获取商品数量
                var count=this.value;
                if (confirm("你确定要将【"+name+"】商品修改数量为："+count+"吗？")){
                    //发起请求。给服务器保存修改
                    location.href="http://localhost:8080/book/cartServlet?action=updateCount&count="+count+"&id="+id;
                }else {
                    //defaultValue属性是表单项Dom对象的属性。它表示默认的value属性值。
                    this.value=this.defaultValue;
                }

            });
        });</script>

</head>
<body>

    <div id="header">
        <img class="logo_img" alt="" src="static/img/logo.gif">
        <span class="wel_word">购物车</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
        <table>
            <tr>
                <td>商品名称</td>
                <td>数量</td>
                <td>单价</td>
                <td>金额</td>
                <td>操作</td>
            </tr>
            <c:if test="${empty sessionScope.cart.items}">
            <%--  如果购物车为空的情况   --%>
                <td colspan="5"><a href="index.jsp"> 亲，当前购物车为空！快跟小伙伴们去浏览商品吧！！！</a></td>
            </c:if>

            <c:if test="${not empty sessionScope.cart.items}">
            <%--  如果购物车非空的情况   --%>
                <c:forEach items="${sessionScope.cart.items}" var="entry">
                    <tr>
                        <td>${entry.value.name}</td>
                        <td>
                            <input class="updateCount" style="width:"
                                   bookId="${entry.value.id}"
                                   type="text" value="${entry.value.count}">
                        </td>
                        <td>${entry.value.price}</td>
                        <td>${entry.value.totalPrice}</td>
                        <td><a class="deleteItem" href="cartServlet?action=deleteItem&id=${entry.value.id}">删除</a></td>
                    </tr>
                </c:forEach>

            </c:if>
        </table>
        <c:if test="${not empty sessionScope.cart.items}">
            <div class="cart_info">
                <span class="cart_span">购物车中共有<span class="b_count">${sessionScope.cart.totalCount}</span>件商品</span>
                <span class="cart_span">总金额<span class="b_price">${sessionScope.cart.totalPrice}</span>元</span>
                <span class="cart_span"><a id="clearCart" href="cartServlet?action=clear">清空购物车</a></span>
                <span class="cart span"><a href="orderServlet?action=createOrder">去结账</a></span>
            </div>
        </c:if>
    </div>



    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

修改 checkout.jsp

<%--
  Created by IntelliJ IDEA.: lenovo
  Date: 2021/8/21
  Time: 下午 02:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>结算页面</title>

    <%--静态包含 base标签，css样式，jquery文件 --%>
    <%@ include file="/pages/common/head.jsp"%>


    <style type="text/css">
    h1 {
        text-align: center;
        margin-top: 200px;
    }
</style>
</head>
<body>
    <div id="header">
        <img class="logo_img" alt="" src="../../static/img/logo.gif">
        <span class="wel_word">结算</span>

        <%-- 静态包含登录成功之后的菜单--%>
        <%@ include file="/pages/common/login_sucess_menu.jsp"%>

    </div>

    <div id="main">
<%--        <h1>你的订单已结算，订单号为：${requestScope.orderId}</h1>--%>
        <h1>你的订单已结算，订单号为：${sessionScope.orderId}</h1>
    </div>

    <%--静态包含页脚内容--%>
    <%@include file="/pages/common/footer.jsp"%>
</body>
</html>

修改 OrderServiceImpl 以解决库存销量bug

package com.atguigu.service.impl;

import com.atguigu.dao.BookDao;
import com.atguigu.dao.OrderDao;
import com.atguigu.dao.OrderItemDao;
import com.atguigu.dao.impl.BookDaoImpl;
import com.atguigu.dao.impl.OrderDaoImpl;
import com.atguigu.dao.impl.OrderItemDaoImpl;
import com.atguigu.pojo.*;
import com.atguigu.service.OrderService;

import java.util.Date;
import java.util.Map;

public class OrderServiceImpl implements OrderService {
    private OrderDao orderDao =new OrderDaoImpl();
    private OrderItemDao orderItemDao=new OrderItemDaoImpl();
    private BookDao bookDao=new BookDaoImpl();
    @Override
    public String createOrder(Cart cart, Integer userId) {
        //订单号==唯一性
        String orderId=System.currentTimeMillis()+""+userId;
        //创建一个订单对象
        Order order=new Order(orderId,new Date(),cart.getTotalPrice(),0,userId);
        //保存订单
        orderDao.saveOrder(order);

        //遍历购物车中每一个商品项转换为订单保存到数据库
        for (Map.Entry<Integer, CartItem>entry:cart.getItems().entrySet()) {
            //获取购物车每一个商品项
            CartItem cartItem=entry.getValue();
            //转换为订单
            OrderItem orderItem=new OrderItem(null,cartItem.getName(),cartItem.getCount(),cartItem.getPrice(),cartItem.getTotalPrice(),orderId);
            //保存到数据库
            orderItemDao.saveOrderItem(orderItem);

            //更新库存和销量
            Book book = bookDao.queryBookById(cartItem.getId());
            book.setSales(book.getSales()+cartItem.getCount());
            book.setStock(book.getStock()-cartItem.getCount());
            bookDao.updateBook(book);
        }
        //清空购物车
        cart.clear();

        return orderId;
    }
}