jsp实验-应用Servlet实现购物车讲解

1、GoodsSingle/保存商品名称/保存商品价格/保存商品购买数量应用Servlet实现购物车具体实现过程1、创建封装商品信息的值JavaBeanpackagecom.yxq.valuebean;publicclassGoodsSingleprivateStringname;privatefloatprice;privateintnum;publicStringgetName()returnname;publicvoidsetName(Stringname)=name;publicintgetNum()returnnum;publicvoidsetNum(intnum)th

2、is.num=num;publicfloatgetPrice()returnprice;publicvoidsetPrice(floatprice)this.price=price;2、创建工具JavaBeanMyTools实现字符型数据转换为整型及乱码处理packagecom.yxq.toolbean;importjava.io.UnsupportedEncodingException;publicclassMyToolspublicstaticintstrToint(Stringstr)/将String型数据转换为int型数据的方法if(str=null|str.equals("

3、")str="0"inti=0;tryi=Integer.parseInt(str);/把str转换成int类型的变量catch(NumberFormatExceptione)/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returni;publicstaticStringtoChinese(Stringstr)/进行转码操作的方法if(str=null)str=""trystr=newString(str.getBytes(

4、"ISO-8859-1"),"gb2312");catch(UnsupportedEncodingExceptione)str=""e.printStackTrace();returnstr;3、创建购物车JavaBeanShopCar实现添加、删除，购物车制作packagecom.yxq.toolbean;packagecom.yxq.toolbean;importjava.util.ArrayList;importcom.yxq.valuebean.GoodsSingle;publicclassShopCarprivateArra

5、yListbuylist=newArrayList();/用来存储购买的商品publicvoidsetBuylist(ArrayListbuylist)this.buylist=buylist;/*功能向购物车中添加商品*参数single为GoodsSingle类对象，圭寸装了要添加的商品信息*/publicvoidaddItem(GoodsSinglesingle)if(single!=null)if(buylist.size()=0)/如果buylist中不存在任何商品GoodsSingletemp=newGoodsSingle();temp.setName(single.getName(

6、);temp.setPrice(single.getPrice();temp.setNum(single.getNum();buylist.add(temp);/存储商品else/如果buylist中存在商品inti=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GoodsSingletemp=(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

7、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GoodsSingletemp=newGoodsSingle();temp.setName(single.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

8、称的商品*参数name表示商品名称*/publicvoidremoveItem(Stringname)for(inti=0;i<buylist.size();i+)/遍历buylist集合，查找指定名称的商品GoodsSingletemp=(GoodsSingle)buylist.get(i);/获取集合中当前位置的商品if(temp.getName().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

9、环elseif(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<%pagecontentType="text/html;charset=gb2312"%><jsp:forwardpage="/index"/>5、创建处理用户访问首页面请求的Servlet-IndexServletpackagecom.yxq.servlet;importjava.io.IOException;importjava.

10、util.ArrayList;importjavax.servlet.ServletException;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletResponse;importjavax.servlet.http.HttpSession;importcom.yxq.valuebean.GoodsSingle;publicclassIndexServletextendsHttpServletprotecte

11、dvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOExceptionHttpSessionsession=request.getSession();session.setAttribute("goodslist",goodslist);response.sendRedirect("show.jsp");static/静态代码块Stringnames="苹果","香蕉","梨&

12、quot;,"橘子"floatprices=2.8f,3.1f,2.5f,2.3f;for(inti=0;i<4;i+)GoodsSinglesingle=newGoodsSingle();single.setName(namesi);single.setPrice(pricesi);single.setNum(1);goodslist.add(single);6、show.jsp显示商品信息<%pagecontentType="text/html;charset=gb2312"%><%pageimport="java.

13、util.ArrayList"%><%pageimport="com.yxq.valuebean.GoodsSingle"%><%ArrayListgoodslist=(ArrayList)session.getAttribute("goodslist");%><tableborder="1"width="450"rules="none"cellspacing="0"cellpadding="0"><

14、;trheight="50"><tdcolspan="3"align="center">提供商品如下</td></tr><tralign="center"height="30"bgcolor="lightgrey"><td>名称</td><td>价格(元/斤)v/td><td>购买v/td></tr><%if(goodslist=null|goo

15、dslist.size()=0)%><trheight="100"><tdcolspan="3"align="center">没有商品可显示！</td></tr><%elsefor(inti=0;ivgoodslist.size();i+)GoodsSinglesingle=(GoodsSingle)goodslist.get(i);%>vtrheight="50"align="center"><td>v%=si

16、nglegetName()%x/td><td>v%=singlegetPrice()%x/td>vtdxahref="doCar?action=buy&id=v%=i%>">购买v/a>v/td>v/tr>v%><trheight="50"><tdalign="center"colspan="3"><ahref="shopcar.jsp">查看购物车</a></td>&

17、lt;/tr></table>7、创建处理用户购买、移除、清空购物车请求的ServletServletBuyServletpackagecom.yxq.servlet;importjava.io.IOException;importjava.util.ArrayList;importjavax.servlet.ServletException;importjavax.servlet.http.HttpServlet;importjavax.servlet.http.HttpServletRequest;importjavax.servlet.http.HttpServletR

18、esponse;importjavax.servlet.http.HttpSession;importcom.yxq.toolbean.MyTools;importcom.yxq.toolbean.ShopCar;importcom.yxq.valuebean.GoodsSingle;publicclassBuyServletextendsHttpServletprotectedvoiddoGet(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOExceptiondoPost(requ

19、est,response);protectedvoiddoPost(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOExceptionStringaction=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

20、品的购买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protectedvoidbuy(HttpServletRequestrequest,HttpServletResponseresponse)throwsServletException,IOExcepti

21、onHttpSessionsession=request.getSession();StringstrId=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intid=MyTools.strToint(strId);ArrayListgoodslist=(ArrayList)session.getAttribute("goodslist");GoodsSinglesingle=(GoodsSingle)goodslist.get(id);ArrayList

22、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=newArrayList();ShopCarmyCar=newShopCar();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/将请求session.setAttribute("buylist

23、",buylist);response.sendRedirect("show.jsp");重定向到show.jsp页面8、在web.xml文件中配置Servlet<?xmlversion="1.0"encoding="UTF-8"?><web-app><!-配置IndexServlet-><servlet><servlet-name>indexServlet</servlet-name><servlet-class>com.yxq.servl

24、et.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</servlet-name><servlet-c

25、lass>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<%pagecontentType="text/html;charset=gb23

26、12"%><%pageimport="java.util.ArrayList"%><%pageimport="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ArrayListbuylist=(ArrayList)session.getAttribute("buylist");floattotal=0;/用来存储应付金额%><tableborder="1"width

27、="450"rules="none"cellspacing="0"cellpadding="0"><trheight="50"><tdcolspan="5"align="center">购买的商品如下</td></tr><tralign="center"height="30"bgcolor="lightgrey"><tdwid

28、th="25%">名称</td><td>价格(元/斤)v/td><td>数量v/td><td>总价(元)</td>vtd>移除(-1/次)</td>v/tr>v%if(buylist=null|buylist.size()=0)%>vtrheight="100">vtdcolspan="5"align="center">您的购物车为空！v/td>v/tr>v%elsefor(inti=0;ivbuylist.size();i+)GoodsSinglesingle=(GoodsSing