一、項目目錄結構

　　

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?二、源代碼

　　dao包——dao層：BookDao.java

1 package com.dao; 2 3 import java.util.Map; 4 5 import com.DB.DB; 6 import com.domain.Book; 7 8 9 10 public class BookDao { 11 12 public Map getAll(){ 13 return DB.getAll(); 14 } 15 16 public Book find(String id){ 17 return (Book) DB.getAll().get(id); 18 } 19 }

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　　DB包：DB.java——模擬數據庫

　　

1 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 8 public class DB { 9 10 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 20 21 public static Map getAll(){ 22 return map; 23 } 24 25 }

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　　domain包：

　　　Book.java:書的實體類

1 package com.domain; 2 //書的實體類 3 public class Book { 4 5 private String id; 6 private String name; 7 private String author; 8 private double price; 9 private String description; 10 11 12 13 14 public Book() { 15 super(); 16 // TODO Auto-generated constructor stub 17 } 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 58 59 }

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　　Cart.java：購物車類

　　　　

1 package com.domain; 2 3 import java.util.LinkedHashMap; 4 import java.util.Map; 5 6 //代表用戶的購物車 7 8 //代表用戶的購物車 9 public class Cart { 10 11 private Map<String,CartItem> map = new LinkedHashMap(); 12 private double price; //記住購物車所有商品多少錢 13 14 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 16 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 27 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 }

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　　CartItem.java:購物項

　　　　

1 package com.domain; 2 //用于代表某個商品，以及商品出現的次數（購物項） 3 public class CartItem { 4 5 private Book book; 6 private int quantity; 7 private double price; 8 9 10 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 30 }

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?　　service包：service層

　　　　BusinessService.java:
　　　　　　

1 package com.service; 2 3 import java.util.Map; 4 5 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 10 public class BusinessService { 11 12 private BookDao dao = new BookDao(); 13 14 public Map getAllBook(){ 15 return dao.getAll(); 16 } 17 18 public Book findBook(String id){ 19 return dao.find(id); 20 } 21 22 //刪除購物車中的購物項 23 public void deleteCartItem(String id, Cart cart) { 24 cart.getMap().remove(id); 25 } 26 27 //清空購物車 28 public void clearCart(Cart cart) { 29 cart.getMap().clear(); 30 } 31 32 //改變購物項的數量 33 public void changeItemQuantity(String id, String quantity, Cart cart) { 34 CartItem item = cart.getMap().get(id); 35 item.setQuantity(Integer.parseInt(quantity)); 36 } 37 38 }

　　　　

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　　web層：

　　　　ListBookServlet.java:顯示所有書籍

　　　　　　

1 package com.web.controller; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 import java.util.Map; 6 7 import javax.servlet.ServletException; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest; 10 import javax.servlet.http.HttpServletResponse; 11 12 import com.service.BusinessService; 13 //獲取所有書籍 14 //獲取所有書 15 public class ListBookServlet extends HttpServlet { 16 17 public void doGet(HttpServletRequest request, HttpServletResponse response) 18 throws ServletException, IOException { 19 20 BusinessService service = new BusinessService(); 21 Map map = service.getAllBook(); 22 request.setAttribute("map", map); 23 24 request.getRequestDispatcher("/WEB-INF/jsp/listbook.jsp").forward(request, response); 25 } 26 27 public void doPost(HttpServletRequest request, HttpServletResponse response) 28 throws ServletException, IOException { 29 doGet(request, response); 30 } 31 32 }

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　　　　BuyServlet.java：處理購買請求

　　　　　　

1 package com.web.controller; 2 3 import java.io.IOException; 4 5 import javax.servlet.ServletException; 6 import javax.servlet.http.HttpServlet; 7 import javax.servlet.http.HttpServletRequest; 8 import javax.servlet.http.HttpServletResponse; 9 10 import com.domain.Book; 11 import com.domain.Cart; 12 import com.service.BusinessService; 13 14 //完成書籍購買 15 //完成書籍購買 16 public class BuyServlet extends HttpServlet { 17 18 public void doGet(HttpServletRequest request, HttpServletResponse response) 19 throws ServletException, IOException { 20 21 String id = request.getParameter("id"); 22 BusinessService service = new BusinessService(); 23 Book book = service.findBook(id); 24 25 //得到用戶的購物車 26 Cart cart = (Cart) request.getSession().getAttribute("cart"); 27 if(cart==null){ 28 cart = new Cart(); 29 request.getSession().setAttribute("cart", cart); 30 } 31 32 //把書加到用戶購物車中,完成購買 33 cart.add(book); 34 35 //response.sendRedirect("/WEB-INF/jsp/listcart.jsp"); 36 request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 37 38 } 39 40 public void doPost(HttpServletRequest request, HttpServletResponse response) 41 throws ServletException, IOException { 42 doGet(request, response); 43 } 44 45 }

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　　　　DeleteItemServlet.java:刪除某一種商品

　　　　　　

1 package com.web.controller; 2 3 import java.io.IOException; 4 5 import javax.servlet.ServletException; 6 import javax.servlet.http.HttpServlet; 7 import javax.servlet.http.HttpServletRequest; 8 import javax.servlet.http.HttpServletResponse; 9 10 import com.domain.Cart; 11 import com.service.BusinessService; 12 //刪除指定的購物項 13 public class DeleteItemServlet extends HttpServlet { 14 15 public void doGet(HttpServletRequest request, HttpServletResponse response) 16 throws ServletException, IOException { 17 18 String id = request.getParameter("id"); 19 Cart cart = (Cart) request.getSession().getAttribute("cart"); 20 21 22 BusinessService service = new BusinessService(); 23 service.deleteCartItem(id,cart); 24 25 //刪除成功 26 request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 27 28 } 29 30 public void doPost(HttpServletRequest request, HttpServletResponse response) 31 throws ServletException, IOException { 32 doGet(request, response); 33 } 34 35 }

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　　　　ClearCartServlet.java:清空購物車

　　　　

1 package com.web.controller; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10 11 import com.domain.Cart; 12 import com.service.BusinessService; 13 //清空購物車 14 public class ClearCartServlet extends HttpServlet { 15 16 public void doGet(HttpServletRequest request, HttpServletResponse response) 17 throws ServletException, IOException { 18 19 Cart cart = (Cart) request.getSession().getAttribute("cart"); 20 21 BusinessService service = new BusinessService(); 22 service.clearCart(cart); 23 24 request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 25 26 } 27 28 public void doPost(HttpServletRequest request, HttpServletResponse response) 29 throws ServletException, IOException { 30 doGet(request, response); 31 } 32 33 }

　　　　

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

　　　　

1 package com.web.controller; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse; 10 11 import com.domain.Cart; 12 import com.service.BusinessService; 13 14 //把購物車中的書修改為指定數量 15 public class ChangeQuantityServlet extends HttpServlet { 16 17 public void doGet(HttpServletRequest request, HttpServletResponse response) 18 throws ServletException, IOException { 19 20 String id = request.getParameter("id"); 21 String quantity = request.getParameter("quantity"); 22 23 Cart cart = (Cart) request.getSession().getAttribute("cart"); 24 25 BusinessService service = new BusinessService(); 26 service.changeItemQuantity(id,quantity,cart); 27 28 29 request.getRequestDispatcher("/WEB-INF/jsp/listcart.jsp").forward(request, response); 30 } 31 32 public void doPost(HttpServletRequest request, HttpServletResponse response) 33 throws ServletException, IOException { 34 doGet(request, response); 35 } 36 37 }

　　　

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　　jsp頁面：

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

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1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> 3 4 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 5 <html> 6 <head> 7 <title>書籍列表頁面</title> 8 </head> 9 10 <body style="text-align: center"> 11 12 <h1>書籍列表</h1> 13 14 <table width="70%" border="1"> 15 <tr> 16 <td>書名</td> 17 <td>作者</td> 18 <td>售價</td> 19 <td>描述 </td> 20 <td>操作</td> 21 </tr> 22 <c:forEach var="entry" items="${map}"> 23 <tr> 24 <td>${entry.value.name }</td> 25 <td>${entry.value.author }</td> 26 <td>${entry.value.price }</td> 27 <td>${entry.value.description } </td> 28 <td> 29 <a href="${pageContext.request.contextPath }/servlet/BuyServlet?id=${entry.value.id }" target="_blank">購買</a> 30 </td> 31 </tr> 32 </c:forEach> 33 </table> 34 35 </body>

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

　　　　

1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> 3 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 4 <html> 5 <head> 6 <title>購物車列表</title> 7 8 <script type="text/javascript"> 9 function deleteitem(id){ 10 var b = window.confirm("您確認刪除嗎？？"); 11 if(b){ 12 window.location.href="${pageContext.request.contextPath }/servlet/DeleteItemServlet?id="+id; 13 } 14 } 15 16 function clearcart(){ 17 var b = window.confirm("您確認清空嗎？？"); 18 if(b){ 19 window.location.href="${pageContext.request.contextPath}/servlet/ClearCartServlet"; 20 } 21 } 22 23 function changeQuantity(input,id,oldvalue){ 24 var quantity = input.value; //得到要修改的數量 sdfsfs 25 26 /* 27 //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 */ 34 35 //檢查用戶輸入的數量是不是一個正整數 36 if(quantity<0 || quantity!=parseInt(quantity)){ 37 alert("請輸入正整數！！"); 38 input.value = oldvalue; 39 return; 40 } 41 42 43 44 var b = window.confirm("您確認把書的數量修改為:" + quantity); 45 if(b){ 46 window.location.href="${pageContext.request.contextPath}/servlet/ChangeQuantityServlet?id=" + id + "&quantity=" + quantity; 47 } 48 } 49 </script> 50 51 </head> 52 53 <body style="text-align: center"> 54 55 <h1>購物車列表</h1> 56 57 <c:if test="${empty(cart.map)}"> 58 您沒有購買任何商品！！！ 59 </c:if> 60 61 62 <c:if test="${!empty(cart.map)}"> 63 <table width="70%" border="1"> 64 <tr> 65 <td>書名</td> 66 <td>作者</td> 67 <td>單價</td> 68 <td>數量 </td> 69 <td>小計</td> 70 <td>操作</td> 71 </tr> 72 <c:forEach var="entry" items="${cart.map}"> 73 <tr> 74 <td>${entry.value.book.name }</td> 75 <td>${entry.value.book.author }</td> 76 <td>${entry.value.book.price }</td> 77 <td> 78 <input type="text" name="quantity" value="${entry.value.quantity }" style="width:35px" onchange="changeQuantity(this,${entry.key},${entry.value.quantity})"> 79 </td> 80 <td>${entry.value.price }</td> 81 <td> 82 <a href="javascript:void(0)" onclick="deleteitem(${entry.key })">刪除</a> <!-- 去掉超鏈接默認行為 --> 83 84 </td> 85 </tr> 86 </c:forEach> 87 88 <tr> 89 <td colspan="3">總價</td> 90 <td colspan="2">${cart.price }元</td> 91 <td colspan="1"> 92 <a href="javascript:void(0)" onclick="clearcart()">清空購物車</a> 93 </td> 94 </tr> 95 </table> 96 </c:if> 97 98 </body> 99 </html>

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轉載于:https://www.cnblogs.com/niuchuangfeng/p/9077503.html

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