购物车案列

一、项目目录结构

　　

 二、源代码

　　dao包——dao层：BookDao.java

package com.dao;

import java.util.Map;

import com.DB.DB;
import com.domain.Book;



public class BookDao {
    
    public Map getAll(){
        return DB.getAll();
    }
    
    public Book find(String id){
        return (Book) DB.getAll().get(id);
    }
}

　　

　　DB包：DB.java——模拟数据库

　　

package com.DB;
import java.util.LinkedHashMap;
import java.util.Map;
import com.domain.Book;
import com.sun.org.apache.bcel.internal.generic.NEW;
//代表数据库
//代表数据库
public class DB {
    
    private static Map map = new LinkedHashMap();
    static{
        map.put("1", new Book("1","javaweb开发","老张",38,"一本好书"));
        map.put("2", new Book("2","jdbc开发","老黎",18,"一本好书"));
        map.put("3", new Book("3","ajax开发","老佟",328,"一本好书"));
        map.put("4", new Book("4","jbpm开发","老毕",58,"一本好书"));
        map.put("5", new Book("5","struts开发","老方",28,"一本好书"));
        map.put("6", new Book("6","spring开发","老方",98,"一本好书"));
    }
    
    
    public static Map getAll(){
        return map;
    }
    
}

　　domain包：

　　　Book.java:书的实体类

package com.domain;
//书的实体类
public class Book {
    
    private String id;
    private String name;
    private String author;
    private double price;
    private String description;
    
    
    
    
    public Book() {
        super();
        // TODO Auto-generated constructor stub
    }
    public Book(String id, String name, String author, double price,
            String description) {
        super();
        this.id = id;
        this.name = name;
        this.author = author;
        this.price = price;
        this.description = description;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAuthor() {
        return author;
    }
    public void setAuthor(String author) {
        this.author = author;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    
    
}

　　　

　　Cart.java：购物车类

　　　　

package com.domain;

import java.util.LinkedHashMap;
import java.util.Map;

//代表用户的购物车

//代表用户的购物车
public class Cart {

    private Map<String,CartItem> map = new LinkedHashMap();
    private double price;  //记住购物车所有商品多少钱
    
    public void add(Book book){
        //看购物车中有没有，要添加的书对应的购物项
        CartItem item = map.get(book.getId());
        if(item==null){
            item = new CartItem();
            item.setBook(book);
            item.setQuantity(1);
            map.put(book.getId(), item);
        }else{
            item.setQuantity(item.getQuantity()+1);
        }
    }
    
    public Map<String, CartItem> getMap() {
        return map;
    }
    public void setMap(Map<String, CartItem> map) {
        this.map = map;
    }
    public double getPrice() {
        double totalprice = 0;
        for(Map.Entry<String, CartItem> entry : map.entrySet()){
            CartItem item = entry.getValue();
            totalprice += item.getPrice();
        }
        this.price = totalprice;
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
}

　　CartItem.java:购物项

　　　　

package com.domain;
//用于代表某个商品，以及商品出现的次数（购物项）
public class CartItem {

    private Book book;
    private int quantity;
    private double price;
    
    
    public Book getBook() {
        return book;
    }
    public void setBook(Book book) {
        this.book = book;
    }
    public int getQuantity() {
        return quantity;
    }
    public void setQuantity(int quantity) {
        this.quantity = quantity;
        this.price = this.book.getPrice() * this.quantity;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }

}

 　　service包：service层

　　　　BusinessService.java:
　　　　　　

package com.service;

import java.util.Map;

import com.dao.BookDao;
import com.domain.Book;
import com.domain.Cart;
import com.domain.CartItem;
//业务类，统一对web层提供所有服务
public class BusinessService {

    private BookDao dao = new BookDao();
    
    public Map getAllBook(){
        return dao.getAll();
    }
    
    public Book findBook(String id){
        return dao.find(id);
    }

    //删除购物车中的购物项
    public void deleteCartItem(String id, Cart cart) {
        cart.getMap().remove(id);
    }
    
    //清空购物车
    public void clearCart(Cart cart) {
        cart.getMap().clear();
    }
    
    //改变购物项的数量
    public void changeItemQuantity(String id, String quantity, Cart cart) {
        CartItem item = cart.getMap().get(id);
        item.setQuantity(Integer.parseInt(quantity));
    }
    
}

　　　　

　　web层：

　　　　ListBookServlet.java:显示所有书籍

　　　　　　

package com.web.controller;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.service.BusinessService;
//获取所有书籍
//获取所有书
public class ListBookServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        BusinessService service = new BusinessService();
        Map map = service.getAllBook();
        request.setAttribute("map", map);
        
        request.getRequestDispatcher("/WEB-INF/jsp/listbook.jsp").forward(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

 

　　　　BuyServlet.java：处理购买请求

　　　　　　

package com.web.controller;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.domain.Book;
import com.domain.Cart;
import com.service.BusinessService;

//完成书籍购买
//完成书籍购买
public class BuyServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String id = request.getParameter("id");
        BusinessService service = new BusinessService();
        Book book = service.findBook(id);
        
        //得到用户的购物车
        Cart cart = (Cart) request.getSession().getAttribute("cart");
        if(cart==null){
            cart = new Cart();
            request.getSession().setAttribute("cart", cart);
        }
        
        //把书加到用户购物车中,完成购买
        cart.add(book);
        
        //response.sendRedirect("/WEB-INF/jsp/listcart.jsp");
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
        
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

　　　　

　　　　DeleteItemServlet.java:删除某一种商品

　　　　　　

package com.web.controller;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.domain.Cart;
import com.service.BusinessService;
//删除指定的购物项
public class DeleteItemServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String id = request.getParameter("id");
        Cart cart = (Cart) request.getSession().getAttribute("cart");
        
        
        BusinessService service = new BusinessService();
        service.deleteCartItem(id,cart);
        
        //删除成功
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
        
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

 　　

　　　　ClearCartServlet.java:清空购物车

　　　　

package com.web.controller;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.domain.Cart;
import com.service.BusinessService;
//清空购物车
public class ClearCartServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        Cart cart = (Cart) request.getSession().getAttribute("cart");
        
        BusinessService service = new BusinessService();
        service.clearCart(cart);
        
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
        
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

　　　　

　　ChangeQuantityServlet.java:修改购物车中指定商品的数量

　　　　

package com.web.controller;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.domain.Cart;
import com.service.BusinessService;

//把购物车中的书修改为指定数量
public class ChangeQuantityServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String id = request.getParameter("id");
        String quantity = request.getParameter("quantity");
        
        Cart cart = (Cart) request.getSession().getAttribute("cart");
        
        BusinessService service = new BusinessService();
        service.changeItemQuantity(id,quantity,cart);
        

        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response);
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }

}

　　　

　　jsp页面：

　　WebRoot/WEB-INF/jsp/listbook.jsp:显示书籍列表

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>书籍列表页面</title>
  </head>
  
  <body style="text-align: center">
    
    <h1>书籍列表</h1>
    
    <table width="70%" border="1">
        <tr>
            <td>书名</td>
            <td>作者</td>
            <td>售价</td>
            <td>描述 </td>
            <td>操作</td>
        </tr>
        <c:forEach var="entry" items="${map}">
            <tr>
                <td>${entry.value.name }</td>
                <td>${entry.value.author }</td>
                <td>${entry.value.price }</td>
                <td>${entry.value.description } </td>
                <td>
                    <a href="${pageContext.request.contextPath }/servlet/BuyServlet?id=${entry.value.id }" target="_blank">购买</a>
                </td>
            </tr>
        </c:forEach>
    </table>
    
  </body>

 　　　

　　WebRoot/WEB-INF/jsp/listcart.jsp：显示购物车列表

　　　　

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>购物车列表</title>
    
    <script type="text/javascript">
        function deleteitem(id){
            var b = window.confirm("您确认删除吗？？");
            if(b){
                window.location.href="${pageContext.request.contextPath }/servlet/DeleteItemServlet?id="+id;
            }
        }
        
        function clearcart(){
            var b = window.confirm("您确认清空吗？？");
            if(b){
                window.location.href="${pageContext.request.contextPath}/servlet/ClearCartServlet";
            }
        }
        
        function changeQuantity(input,id,oldvalue){
            var quantity = input.value;   //得到要修改的数量 sdfsfs
            
            /*
            //检查用户输入的数量是不是一个数字
            if(isNaN(quantity)){
                alert("请输入数字！！");
                input.value = oldvalue;
                return;
            }
            */
            
            //检查用户输入的数量是不是一个正整数
            if(quantity<0 || quantity!=parseInt(quantity)){
                alert("请输入正整数！！");
                input.value = oldvalue;
                return;
            }
            
            
            
            var b = window.confirm("您确认把书的数量修改为:" + quantity);
            if(b){
                window.location.href="${pageContext.request.contextPath}/servlet/ChangeQuantityServlet?id=" + id + "&quantity=" + quantity;
            }
        }
    </script>
    
  </head>
  
  <body style="text-align: center">
    
    <h1>购物车列表</h1>
    
    <c:if test="${empty(cart.map)}"> 
        您没有购买任何商品！！！
    </c:if>
   
   
       <c:if test="${!empty(cart.map)}"> 
    <table width="70%" border="1">
        <tr>
            <td>书名</td>
            <td>作者</td>
            <td>单价</td>
            <td>数量 </td>
            <td>小计</td>
            <td>操作</td>
        </tr>
        <c:forEach var="entry" items="${cart.map}">
            <tr>
                <td>${entry.value.book.name }</td>
                <td>${entry.value.book.author }</td>
                <td>${entry.value.book.price }</td>
                <td>
                    <input type="text" name="quantity" value="${entry.value.quantity }" style="35px" onchange="changeQuantity(this,${entry.key},${entry.value.quantity})">
                </td>
                <td>${entry.value.price }</td>
                <td>
                    <a href="javascript:void(0)" onclick="deleteitem(${entry.key })">删除</a>  <!-- 去掉超链接默认行为 -->
                    
                </td>
            </tr>
        </c:forEach>
        
        <tr>
            <td colspan="3">总价</td>
            <td colspan="2">${cart.price }元</td>
            <td colspan="1">
                <a href="javascript:void(0)" onclick="clearcart()">清空购物车</a>
            </td>
        </tr>
    </table>
     </c:if>
    
  </body>
</html>