jsp实验-应用Servlet实现购物车

1、应用Servlet实现购物车具体实现过程1、 创建封装商品信息的值JavaBean-GoodsSinglepackage com.yxq.valuebean;public class GoodsSingle private String name;/保存商品名称private float price; /保存商品价格private int num;/保存商品购买数量public String getName() return name;public void setName(String name) = name;public int getNum() return num

2、;public void setNum(int num) this.num = num;public float getPrice() return price;public void setPrice(float price) this.price = price;2、 创建工具JavaBean- MyTools 实现字符型数据转换为整型及乱码处理package com.yxq.toolbean;import java.io.UnsupportedEncodingException;public class MyTools public static int strToint(String

3、str)/将String型数据转换为int型数据的方法if(str=null|str.equals("")str="0"int i=0;tryi=Integer.parseInt(str); /把str 转换成 int 类型的变量catch(NumberFormatException e) / try-catch就是监视try中的语句,如果抛出catch中声明的异常类型i=0;e.printStackTrace(); /把Exception的详细信息打印出来return i;public static String toChinese(String st

4、r)/进行转码操作的方法if(str=null)str=""try str=new String(str.getBytes("ISO-8859-1"),"gb2312"); catch (UnsupportedEncodingException e) str=""e.printStackTrace();return str;3、 创建购物车JavaBean- ShopCar实现添加、删除，购物车制作package com.yxq.toolbean;package com.yxq.toolbean;import ja

5、va.util.ArrayList;import com.yxq.valuebean.GoodsSingle;public class ShopCar private ArrayList buylist=new ArrayList();/用来存储购买的商品public void setBuylist(ArrayList buylist) this.buylist = buylist;/* * 功能 向购物车中添加商品 * 参数 single为GoodsSingle类对象，封装了要添加的商品信息 */public void addItem(GoodsSingle single)if(single

6、!=null)if(buylist.size()=0)/如果buylist中不存在任何商品GoodsSingle temp=new GoodsSingle();temp.setName(single.getName();temp.setPrice(single.getPrice();temp.setNum(single.getNum();buylist.add(temp);/存储商品else/如果buylist中存在商品int i=0;for(;i<buylist.size();i+)/遍历buylist集合对象，判断该集合中是否已经存在当前要添加的商品GoodsSingle temp=

7、(GoodsSingle)buylist.get(i);/获取buylist集合中当前元素if(temp.getName().equals(single.getName()/判断从buylist集合中获取的当前商品的名称是否与要添加的商品的名称相同/如果相同，说明已经购买了该商品，只需要将商品的购买数量加1temp.setNum(temp.getNum()+1);/将商品购买数量加1break;/结束for循环if(i>=buylist.size()/说明buylist中不存在要添加的商品GoodsSingle temp=new GoodsSingle();temp.setName(si

8、ngle.getName();temp.setPrice(single.getPrice();temp.setNum(single.getNum();buylist.add(temp);/存储商品/* * 功能 从购物车中移除指定名称的商品 * 参数 name表示商品名称 */public void removeItem(String name)for(int i=0;i<buylist.size();i+)/遍历buylist集合，查找指定名称的商品GoodsSingle temp=(GoodsSingle)buylist.get(i); /获取集合中当前位置的商品if(temp.ge

9、tName().equals(name)/如果商品的名称为name参数指定的名称if(temp.getNum()>1)/如果商品的购买数量大于1temp.setNum(temp.getNum()-1);/则将购买数量减1break; /结束for循环else if(temp.getNum()=1)/如果商品的购买数量为1buylist.remove(i); /从buylist集合对象中移除该商品4、 创建实例首页面index.jsp，初始化商品信息<% page contentType="text/html;charset=gb2312"%><jsp

10、:forward page="/index"/>5、 创建处理用户访问首页面请求的Servlet- IndexServletpackage com.yxq.servlet;import java.io.IOException;import java.util.ArrayList;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.

11、HttpServletResponse;import javax.servlet.http.HttpSession;import com.yxq.valuebean.GoodsSingle;public class IndexServlet extends HttpServlet protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException HttpSession session=request.getSession();s

12、ession.setAttribute("goodslist",goodslist);response.sendRedirect("show.jsp");static/静态代码块String names="苹果","香蕉","梨","橘子"float prices=2.8f,3.1f,2.5f,2.3f;for(int i=0;i<4;i+)GoodsSingle single=new GoodsSingle();single.setName(namesi);singl

13、e.setPrice(pricesi);single.setNum(1);goodslist.add(single);6、 show.jsp显示商品信息<% page contentType="text/html;charset=gb2312"%><% page import="java.util.ArrayList" %><% page import="com.yxq.valuebean.GoodsSingle" %><%ArrayList goodslist=(ArrayList)sess

14、ion.getAttribute("goodslist");%><table border="1" width="450" rules="none" cellspacing="0" cellpadding="0"><tr height="50"><td colspan="3" align="center">提供商品如下</td></tr><tr

15、align="center" height="30" bgcolor="lightgrey"><td>名称</td><td>价格(元/斤)</td><td>购买</td></tr><% if(goodslist=null|goodslist.size()=0) %><tr height="100"><td colspan="3" align="center"

16、>没有商品可显示！</td></tr><% elsefor(int i=0;i<goodslist.size();i+)GoodsSingle single=(GoodsSingle)goodslist.get(i);%><tr height="50" align="center"><td><%=single.getName()%></td><td><%=single.getPrice()%></td><td>&

17、lt;a href="doCar?action=buy&id=<%=i%>">购买</a></td></tr><%><tr height="50"><td align="center" colspan="3"><a href="shopcar.jsp">查看购物车</a></td></tr></table>7、 创建处理用户购买、移除、清空

18、购物车请求的Servlet Servlet- BuyServletpackage com.yxq.servlet;import java.io.IOException;import java.util.ArrayList;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.h

19、ttp.HttpSession;import com.yxq.toolbean.MyTools;import com.yxq.toolbean.ShopCar;import com.yxq.valuebean.GoodsSingle;public class BuyServlet extends HttpServlet protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException doPost(request,response

20、);protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException String action=request.getParameter("action");/获取action参数值if(action=null)action=""if(action.equals("buy")/触发了“购买”请求buy(request,response);/调用buy()方法实现商品的

21、购买if(action.equals("remove")/触发了“移除”请求remove(request,response);/调用remove()方法实现商品的移除if(action.equals("clear")/触发了“清空购物车”请求clear(request,response);/调用clear()方法实现购物车的清空/实现购买商品的方法protected void buy(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOE

22、xception HttpSession session=request.getSession();String strId=request.getParameter("id");/获取触发“购买”请求时传递的id参数，该参数存储的是商品在goodslist对象中存储的位置int id=MyTools.strToint(strId);ArrayList goodslist=(ArrayList)session.getAttribute("goodslist");GoodsSingle single=(GoodsSingle)goodslist.get(i

23、d);ArrayList buylist=(ArrayList)session.getAttribute("buylist");/从session范围内获取存储了用户已购买商品的集合对象if(buylist=null)buylist=new ArrayList();ShopCar myCar=new ShopCar();myCar.setBuylist(buylist); /将buylist对象赋值给ShopCar类实例中的属性myCar.addItem(single);/调用ShopCar类中addItem()方法实现商品添加操作session.setAttribute(

24、"buylist",buylist);response.sendRedirect("show.jsp");/将请求重定向到show.jsp页面8、 在web.xml文件中配置Servlet<?xml version="1.0" encoding="UTF-8"?><web-app><!- 配置IndexServlet -><servlet><servlet-name>indexServlet</servlet-name><servlet-

25、class>com.yxq.servlet.IndexServlet</servlet-class></servlet><servlet-mapping><servlet-name>indexServlet</servlet-name><url-pattern>/index</url-pattern></servlet-mapping> <!- 配置BuyServlet -><servlet><servlet-name>buyServlet</serv

26、let-name><servlet-class>com.yxq.servlet.BuyServlet</servlet-class></servlet><servlet-mapping><servlet-name>buyServlet</servlet-name><url-pattern>/doCar</url-pattern></servlet-mapping></web-app>9、 创建页面shopcar.jsp购物车<% page contentType=

27、"text/html;charset=gb2312"%><% page import="java.util.ArrayList" %><% page import="com.yxq.valuebean.GoodsSingle" %><% /获取存储在session中用来存储用户已购买商品的buylist集合对象ArrayList buylist=(ArrayList)session.getAttribute("buylist");float total=0; /用来存储应付金额%

28、><table border="1" width="450" rules="none" cellspacing="0" cellpadding="0"><tr height="50"><td colspan="5" align="center">购买的商品如下</td></tr><tr align="center" height="30

29、" bgcolor="lightgrey"><td width="25%">名称</td><td>价格(元/斤)</td><td>数量</td><td>总价(元)</td><td>移除(-1/次)</td></tr><%if(buylist=null|buylist.size()=0) %><tr height="100"><td colspan="5" align="center">您的购物车为空！</td></tr><% elsefor(int i=0;i<buylist.size();i+)GoodsSi