1.大纲设计
2.shopingCartItem.java
1 package beans; 2 3 public class shopingCartItem { 4 private String bookname;//书对象 5 private int num; //书的数量 6 private int price; // 书的价格 7 public int getNum() { 8 return num; 9 } 10 public void setNum(int num) { 11 this.num = num; 12 } 13 public String getBookname() { 14 return bookname; 15 } 16 public void setBookname(String bookname) { 17 this.bookname = bookname; 18 } 19 public int getPrice() { 20 return price; 21 } 22 public void setPrice(int price) { 23 this.price = price; 24 } 25 }
3.shopingCart.java
1 package beans; 2 3 import java.util.HashMap; 4 import java.util.Map; 5 6 public class shopingCart { 7 //存放shopingCartItem的map，键是书名，值是shopingCartItem对象 8 private Map<String,shopingCartItem> items=new HashMap<>(); 9 /** 10 * 将书名与书的价格添加到购物车 11 * @param bookName 12 * @param price 13 */ 14 public void addToCart(String bookName,int price) { 15 if(items.containsKey(bookName)) { 16 shopingCartItem item=items.get(bookName); 17 item.setNum(item.getNum()+1); 18 }else { 19 shopingCartItem item=new shopingCartItem(); 20 item.setBookname(bookName); 21 item.setPrice(price); 22 item.setNum(1); 23 items.put(bookName, item); 24 } 25 } 26 /** 27 * 返回书的总数量 28 * @return 29 */ 30 public int totalBookNumer() { 31 int totalNum=0; 32 for(shopingCartItem item:items.values()) { 33 totalNum+=item.getNum(); 34 } 35 return totalNum; 36 } 37 /** 38 * 返回书的总价钱 39 */ 40 public int totalBookPrice() { 41 int totalPrice=0; 42 for(shopingCartItem item:items.values()) { 43 totalPrice+=item.getNum()*item.getPrice(); 44 } 45 return totalPrice; 46 } 47 }
4.AddToCartServlet.java
1 package servlets; 2 3 import java.io.IOException; 4 5 import javax.servlet.Servlet; 6 import javax.servlet.ServletConfig; 7 import javax.servlet.ServletException; 8 import javax.servlet.ServletRequest; 9 import javax.servlet.ServletResponse; 10 import javax.servlet.http.HttpServlet; 11 import javax.servlet.http.HttpServletRequest; 12 import javax.servlet.http.HttpServletResponse; 13 import javax.servlet.http.HttpSession; 14 15 import beans.shopingCart; 16 17 public class AddToCartServlet extends HttpServlet { 18 19 private static final long serialVersionUID = 1L; 20 21 @Override 22 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 23 doPost(request,response); 24 } 25 26 @Override 27 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 28 //获取请求参数 29 String bookName=request.getParameter("id"); 30 int price=Integer.parseInt(request.getParameter("price")); 31 //获取购物车对象 32 HttpSession session=request.getSession(); 33 shopingCart sc=(shopingCart)session.getAttribute("sc"); 34 if(sc==null) { 35 sc=new shopingCart(); 36 session.setAttribute("sc", sc); 37 } 38 //将点击的事件放入购物车 39 sc.addToCart(bookName, price); 40 //准备响应的JSON对象 41 StringBuilder result=new StringBuilder(); 42 result.append("{") 43 .append(""bookName":""+bookName+""") 44 .append(",") 45 .append(""totalBookName":""+sc.totalBookNumer()+""") 46 .append(",") 47 .append(""totalPrice":""+sc.totalBookPrice()+""") 48 .append("}"); 49 50 //响应JSON对象 51 response.setContentType("text/javascript"); 52 response.getWriter().print(result.toString()); 53 } 54 55 56 }
5.index.jsp
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 7 <title>Insert title here</title> 8 <script type="text/javascript" src="${pageContext.request.contextPath}/shopcart/jquery-3.2.1.min.js"></script> 9 <script type="text/javascript"> 10 $(function(){ 11 $("a").click(function(){ 12 alert(1); 13 var url=this.href; 14 var args={"time":new Date()}; 15 $.getJSON(url,args,function(data){ 16 $("#bookName").text(data.bookName); 17 $("#totalBookName").text(data.totalBookName); 18 $("#totalPrice").text(data.totalPrice); 19 }); 20 return false; 21 }) 22 }) 23 </script> 24 </head> 25 <body> 26 你已经将 <span id="bookName"></span> 加入到购物车中， 27 购物车中有 <span id="totalBookName"></span> 本书， 28 总价 <span id="totalPrice"></span> <br><br> 29 30 Java<a href="${pageContext.request.contextPath}/addToCart?id=java&price=100">加入购物车</a><br> 31 Oracle<a href="${pageContext.request.contextPath}/addToCart?id=Oracle&price=100">加入购物车</a><br> 32 Ajax<a href="${pageContext.request.contextPath}/addToCart?id=Ajax&price=100">加入购物车</a><br> 33 </body> 34 </html>
6.效果
