購物車案列

一、項目目錄結構

　　

 

 二、源代碼

　　dao包——dao層：BookDao.java

package com.dao;  2 
import java.util.Map;  4 
import com.DB.DB;  6 import com.domain.Book;  7 


public class BookDao { 11     
    public Map getAll(){ 13         return DB.getAll(); 14  } 15     
    public Book find(String id){ 17         return (Book) DB.getAll().get(id); 18  } 19 }

 

　　

 

　　DB包：DB.java——模擬數據庫

　　

package com.DB;  2 import java.util.LinkedHashMap;  3 import java.util.Map;  4 import com.domain.Book;  5 import com.sun.org.apache.bcel.internal.generic.NEW;  6 //代表數據庫  7 //代表數據庫
public class DB {  9     
    private static Map map = new LinkedHashMap(); 11     static{ 12         map.put("1", new Book("1","javaweb開發","老張",38,"一本好書")); 13         map.put("2", new Book("2","jdbc開發","老黎",18,"一本好書")); 14         map.put("3", new Book("3","ajax開發","老佟",328,"一本好書")); 15         map.put("4", new Book("4","jbpm開發","老畢",58,"一本好書")); 16         map.put("5", new Book("5","struts開發","老方",28,"一本好書")); 17         map.put("6", new Book("6","spring開發","老方",98,"一本好書")); 18  } 19     
    
    public static Map getAll(){ 22         return map; 23  } 24     
}

 

 

　　domain包：

　　　Book.java:書的實體類

package com.domain;  2 //書的實體類
public class Book {  4     
    private String id;  6     private String name;  7     private String author;  8     private double price;  9     private String description; 10     
    
    
    
    public Book() { 15         super(); 16         // TODO Auto-generated constructor stub
 } 18     public Book(String id, String name, String author, double price, 19  String description) { 20         super(); 21         this.id = id; 22         this.name = name; 23         this.author = author; 24         this.price = price; 25         this.description = description; 26  } 27     public String getId() { 28         return id; 29  } 30     public void setId(String id) { 31         this.id = id; 32  } 33     public String getName() { 34         return name; 35  } 36     public void setName(String name) { 37         this.name = name; 38  } 39     public String getAuthor() { 40         return author; 41  } 42     public void setAuthor(String author) { 43         this.author = author; 44  } 45     public double getPrice() { 46         return price; 47  } 48     public void setPrice(double price) { 49         this.price = price; 50  } 51     public String getDescription() { 52         return description; 53  } 54     public void setDescription(String description) { 55         this.description = description; 56  } 57     
    
}

 

　　　

　　Cart.java：購物車類

　　　　

package com.domain;  2 
import java.util.LinkedHashMap;  4 import java.util.Map;  5 
//代表用戶的購物車  7 
//代表用戶的購物車
public class Cart { 10 
    private Map<String,CartItem> map = new LinkedHashMap(); 12     private double price;  //記住購物車所有商品多少錢
    
    public void add(Book book){ 15         //看購物車中有沒有，要添加的書對應的購物項
        CartItem item = map.get(book.getId()); 17         if(item==null){ 18             item = new CartItem(); 19  item.setBook(book); 20             item.setQuantity(1); 21  map.put(book.getId(), item); 22         }else{ 23             item.setQuantity(item.getQuantity()+1); 24  } 25  } 26     
    public Map<String, CartItem> getMap() { 28         return map; 29  } 30     public void setMap(Map<String, CartItem> map) { 31         this.map = map; 32  } 33     public double getPrice() { 34         double totalprice = 0; 35         for(Map.Entry<String, CartItem> entry : map.entrySet()){ 36             CartItem item = entry.getValue(); 37             totalprice += item.getPrice(); 38  } 39         this.price = totalprice; 40         return price; 41  } 42     public void setPrice(double price) { 43         this.price = price; 44  } 45 }

 

　　CartItem.java:購物項

　　　　

package com.domain;  2 //用於代表某個商品，以及商品出現的次數（購物項）
public class CartItem {  4 
    private Book book;  6     private int quantity;  7     private double price;  8     
    
    public Book getBook() { 11         return book; 12  } 13     public void setBook(Book book) { 14         this.book = book; 15  } 16     public int getQuantity() { 17         return quantity; 18  } 19     public void setQuantity(int quantity) { 20         this.quantity = quantity; 21         this.price = this.book.getPrice() * this.quantity; 22  } 23     public double getPrice() { 24         return price; 25  } 26     public void setPrice(double price) { 27         this.price = price; 28  } 29 
}

 

 　　service包：service層

　　　　BusinessService.java:
　　　　　　

package com.service;  2 
import java.util.Map;  4 
import com.dao.BookDao;  6 import com.domain.Book;  7 import com.domain.Cart;  8 import com.domain.CartItem;  9 //業務類，統一對web層提供所有服務
public class BusinessService { 11 
    private BookDao dao = new BookDao(); 13     
    public Map getAllBook(){ 15         return dao.getAll(); 16  } 17     
    public Book findBook(String id){ 19         return dao.find(id); 20  } 21 
    //刪除購物車中的購物項
    public void deleteCartItem(String id, Cart cart) { 24  cart.getMap().remove(id); 25  } 26     
    //清空購物車
    public void clearCart(Cart cart) { 29  cart.getMap().clear(); 30  } 31     
    //改變購物項的數量
    public void changeItemQuantity(String id, String quantity, Cart cart) { 34         CartItem item = cart.getMap().get(id); 35  item.setQuantity(Integer.parseInt(quantity)); 36  } 37     
}

　　　　

 

　　web層：

　　　　ListBookServlet.java:顯示所有書籍

　　　　　　

package com.web.controller;  2 
import java.io.IOException;  4 import java.io.PrintWriter;  5 import java.util.Map;  6 
import javax.servlet.ServletException;  8 import javax.servlet.http.HttpServlet;  9 import javax.servlet.http.HttpServletRequest; 10 import javax.servlet.http.HttpServletResponse; 11 
import com.service.BusinessService; 13 //獲取所有書籍 14 //獲取所有書
public class ListBookServlet extends HttpServlet { 16 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 18             throws ServletException, IOException { 19 
        BusinessService service = new BusinessService(); 21         Map map = service.getAllBook(); 22         request.setAttribute("map", map); 23         
        request.getRequestDispatcher("/WEB-INF/jsp/listbook.jsp").forward(request, response); 25  } 26 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 28             throws ServletException, IOException { 29  doGet(request, response); 30  } 31 
}

 

 

　　　　BuyServlet.java：處理購買請求

　　　　　　

package com.web.controller;  2 
import java.io.IOException;  4 
import javax.servlet.ServletException;  6 import javax.servlet.http.HttpServlet;  7 import javax.servlet.http.HttpServletRequest;  8 import javax.servlet.http.HttpServletResponse;  9 
import com.domain.Book; 11 import com.domain.Cart; 12 import com.service.BusinessService; 13 
//完成書籍購買 15 //完成書籍購買
public class BuyServlet extends HttpServlet { 17 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 19             throws ServletException, IOException { 20 
        String id = request.getParameter("id"); 22         BusinessService service = new BusinessService(); 23         Book book = service.findBook(id); 24         
        //得到用戶的購物車
        Cart cart = (Cart) request.getSession().getAttribute("cart"); 27         if(cart==null){ 28             cart = new Cart(); 29             request.getSession().setAttribute("cart", cart); 30  } 31         
        //把書加到用戶購物車中,完成購買
 cart.add(book); 34         
        //response.sendRedirect("/WEB-INF/jsp/listcart.jsp");
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 37         
 } 39 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 41             throws ServletException, IOException { 42  doGet(request, response); 43  } 44 
}

 

 

 

　　　　

　　　　DeleteItemServlet.java:刪除某一種商品

　　　　　　

package com.web.controller;  2 
import java.io.IOException;  4 
import javax.servlet.ServletException;  6 import javax.servlet.http.HttpServlet;  7 import javax.servlet.http.HttpServletRequest;  8 import javax.servlet.http.HttpServletResponse;  9 
import com.domain.Cart; 11 import com.service.BusinessService; 12 //刪除指定的購物項
public class DeleteItemServlet extends HttpServlet { 14 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 16             throws ServletException, IOException { 17 
        String id = request.getParameter("id"); 19         Cart cart = (Cart) request.getSession().getAttribute("cart"); 20         
        
        BusinessService service = new BusinessService(); 23  service.deleteCartItem(id,cart); 24         
        //刪除成功
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 27         
 } 29 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 31             throws ServletException, IOException { 32  doGet(request, response); 33  } 34 
}

 

 

 

 　　

　　　　ClearCartServlet.java:清空購物車

　　　　

package com.web.controller;  2 
import java.io.IOException;  4 import java.io.PrintWriter;  5 
import javax.servlet.ServletException;  7 import javax.servlet.http.HttpServlet;  8 import javax.servlet.http.HttpServletRequest;  9 import javax.servlet.http.HttpServletResponse; 10 
import com.domain.Cart; 12 import com.service.BusinessService; 13 //清空購物車
public class ClearCartServlet extends HttpServlet { 15 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 17             throws ServletException, IOException { 18 
        Cart cart = (Cart) request.getSession().getAttribute("cart"); 20         
        BusinessService service = new BusinessService(); 22  service.clearCart(cart); 23         
        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 25         
 } 27 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 29             throws ServletException, IOException { 30  doGet(request, response); 31  } 32 
}

　　　　

　　ChangeQuantityServlet.java:修改購物車中指定商品的數量

　　　　

package com.web.controller;  2 
import java.io.IOException;  4 import java.io.PrintWriter;  5 
import javax.servlet.ServletException;  7 import javax.servlet.http.HttpServlet;  8 import javax.servlet.http.HttpServletRequest;  9 import javax.servlet.http.HttpServletResponse; 10 
import com.domain.Cart; 12 import com.service.BusinessService; 13 
//把購物車中的書修改為指定數量
public class ChangeQuantityServlet extends HttpServlet { 16 
    public void doGet(HttpServletRequest request, HttpServletResponse response) 18             throws ServletException, IOException { 19 
        String id = request.getParameter("id"); 21         String quantity = request.getParameter("quantity"); 22         
        Cart cart = (Cart) request.getSession().getAttribute("cart"); 24         
        BusinessService service = new BusinessService(); 26  service.changeItemQuantity(id,quantity,cart); 27         

        request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 30  } 31 
    public void doPost(HttpServletRequest request, HttpServletResponse response) 33             throws ServletException, IOException { 34  doGet(request, response); 35  } 36 
}

　　　

 

 

　　jsp頁面：

 

　　WebRoot/WEB-INF/jsp/listbook.jsp:顯示書籍列表

 

<%@ 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>書籍列表頁面</title>
  </head>
  
  <body style="text-align: center">
    
    <h1>書籍列表</h1>
    
    <table width="70%" border="1">
        <tr>
            <td>書名</td>
            <td>作者</td>
            <td>售價</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">購買</a>
                </td>
            </tr>
        </c:forEach>
    </table>
    
  </body>

 

 　　　

 

　　WebRoot/WEB-INF/jsp/listcart.jsp：顯示購物車列表

　　　　

<%@ 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>購物車列表</title>
    
    <script type="text/javascript">
        function deleteitem(id){ 10             var b = window.confirm("您確認刪除嗎？？"); 11             if(b){ 12  window.location.href="${pageContext.request.contextPath }/servlet/DeleteItemServlet?id="+id; 13  } 14  } 15         
        function clearcart(){ 17             var b = window.confirm("您確認清空嗎？？"); 18             if(b){ 19  window.location.href="${pageContext.request.contextPath}/servlet/ClearCartServlet"; 20  } 21  } 22         
        function changeQuantity(input,id,oldvalue){ 24             var quantity = input.value; //得到要修改的數量 sdfsfs
            
            /*
 //檢查用戶輸入的數量是不是一個數字 28  if(isNaN(quantity)){ 29  alert("請輸入數字！！"); 30  input.value = oldvalue; 31  return; 32  } 33             */
            
            //檢查用戶輸入的數量是不是一個正整數
            if(quantity<0 || quantity!=parseInt(quantity)){ 37  alert("請輸入正整數！！"); 38  input.value = oldvalue; 39                 return; 40  } 41             
            
            
            var b = window.confirm("您確認把書的數量修改為:" + quantity); 45             if(b){ 46  window.location.href="${pageContext.request.contextPath}/servlet/ChangeQuantityServlet?id=" + id + "&quantity=" + quantity; 47  } 48  } 49     </script>
    
  </head>
  
  <body style="text-align: center">
    
    <h1>購物車列表</h1>
    
    <c:if test="${empty(cart.map)}"> 
 您沒有購買任何商品！！！ 59     </c:if>
   
   
       <c:if test="${!empty(cart.map)}"> 
    <table width="70%" border="1">
        <tr>
            <td>書名</td>
            <td>作者</td>
            <td>單價</td>
            <td>數量 </td>
            <td>小計</td>
            <td>操作</td>
        </tr>
        <c:forEach var="entry" items="${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="width: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 })">刪除</a>  <!-- 去掉超鏈接默認行為 -->
                    
                </td>
            </tr>
        </c:forEach>
        
        <tr>
            <td colspan="3">總價</td>
            <td colspan="2">${cart.price }元</td>
            <td colspan="1">
                <a href="javascript:void(0)" onclick="clearcart()">清空購物車</a>
            </td>
        </tr>
    </table>
     </c:if>
    
  </body>
</html>