摘要：用jsp和servlet制作一个简单的购物车
1，首先需要一个用来选择商品的JSP页面
程序如下：
1 <%@ page language="java" import="java.util.*" pageEncoding="GBK" contentType="text/html; charset=GBK"%> 2 <% 3 String path = request.getContextPath(); 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 5 %> 6 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 8 <html> 9 <head> 10 <base href="<%=basePath%>"> 11 12 <title>My JSP 'Buy.jsp' starting page</title> 13 14 <meta http-equiv="pragma" content="no-cache"> 15 <meta http-equiv="cache-control" content="no-cache"> 16 <meta http-equiv="expires" content="0"> 17 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 18 <meta http-equiv="description" content="This is my page"> 19 <!-- 20 <link rel="stylesheet" type="text/css" href="styles.css"> 21 --> 22 23 </head> 24 25 <body> 26 <form action="buycar" method="post"> 27 电脑:<input type="checkbox" name="goods" value="computer"><br/> 28 手机:<input type="checkbox" name="goods" value="phone"><br/> 29 手表:<input type="checkbox" name="goods" value="watch"><br/> 30 <input type="submit" value="购买"/> 31 </form> 32 33 34 </body> 35 </html>
2，需要一个servlet服务端
程序如下：
1 package servlet; 2 3 import java.io.IOException; 4 import java.util.HashMap; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.annotation.WebServlet; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest; 10 import javax.servlet.http.HttpServletResponse; 11 import javax.servlet.http.HttpSession; 12 13 @WebServlet(urlPatterns={"/buycar"}) 14 public class ShopCar extends HttpServlet{ 15 private HttpSession hts; 16 HashMap<String, Integer> hs=new HashMap<String, Integer>(); 17 static int sumcom=0; 18 static int sumphone=0; 19 static int sumwatch=0; 20 @Override 21 protected void service(HttpServletRequest req, HttpServletResponse res) 22 throws ServletException, IOException { 23 req.setCharacterEncoding("GBK"); 24 String[] goodshop=req.getParameterValues("goods"); 25 for(String goods:goodshop){ 26 if("computer".equals(goods)){ 27 hs.put("电脑", ++sumcom); 28 } 29 if("phone".equals(goods)){ 30 hs.put("手机", ++sumphone); 31 } 32 if("watch".equals(goods)){ 33 hs.put("手表", ++sumwatch); 34 } 35 } 36 hts=req.getSession(); 37 hts.setAttribute("shoppingCar", hs); 38 req.getRequestDispatcher("shoppcar.jsp").forward(req, res); 39 } 40 41 }
3，需要一个购买到商品的显示页面
程序如下：
1 <%@ page language="java" import="java.util.*" pageEncoding="GBK" contentType="text/html; charset=GBK"%> 2 <% 3 String path = request.getContextPath(); 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 5 %> 6 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 8 <html> 9 <head> 10 <base href="<%=basePath%>"> 11 12 <title>My JSP 'shoppcar.jsp' starting page</title> 13 14 <meta http-equiv="pragma" content="no-cache"> 15 <meta http-equiv="cache-control" content="no-cache"> 16 <meta http-equiv="expires" content="0"> 17 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 18 <meta http-equiv="description" content="This is my page"> 19 <!-- 20 <link rel="stylesheet" type="text/css" href="styles.css"> 21 --> 22 23 </head> 24 25 <body> 26 <% 27 request.setCharacterEncoding("GBK"); 28 HashMap<String,Integer> hs=(HashMap<String,Integer>)session.getAttribute("shoppingCar"); 29 if(hs!=null){ 30 Set set=hs.keySet(); 31 Iterator<String> it=set.iterator(); 32 while(it.hasNext()){ 33 String key=it.next(); 34 if(key.equals("电脑")){ 35 out.print("购买电脑"+hs.get(key)+"台"); 36 } 37 if(key.equals("手机")){ 38 out.print("购买手机"+hs.get(key)+"台"); 39 } 40 if(key.equals("手表")){ 41 out.print("购买手表"+hs.get(key)+"台"); 42 } 43 } 44 } 45 46 47 48 49 %> 50 51 <a hres="Buy.jsp">继续购买</a> 52 </body> 53 </html>