Session简单实现购物车功能
这个小程序主要就3个页面，一个商品列表页面(HomeServlet)，一个是提示加入购物车页面(AddCartTipServlet)，一个是显示购物车清单页面(ShowCartServlet)。
HomeServlet页面：
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@WebServlet({ "/HomeServlet", "/home" })public class HomeServlet extends HttpServlet { private static final long serialVersionUID = 1L; public HomeServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); out.print("<h2>书单</h2><hr/><br/>"); out.print("人类简史<a href='"+request.getContextPath()+"/addCartTip?id=1'>加入购物车</a><br/>"); out.print("未来简史<a href='"+request.getContextPath()+"/addCartTip?id=2'>加入购物车</a><br/>"); out.print("世界简史<a href='"+request.getContextPath()+"/addCartTip?id=3'>加入购物车</a><br/>"); out.print("时间简史<a href='"+request.getContextPath()+"/addCartTip?id=4'>加入购物车</a><br/>"); out.print("<a href='"+request.getContextPath()+"/show/cart'>查看购物车</a><br/>"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} |
AddCartTipServlet页面：
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@WebServlet({ "/AddCartTipsServlet", "/addCartTip" })public class AddCartTipsServlet extends HttpServlet { private static final long serialVersionUID = 1L; public AddCartTipsServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); HttpSession session = request.getSession(); List<String> list = (List<String>) session.getAttribute("cart"); if(list==null){ list=new ArrayList<>(); } String id = request.getParameter("id"); list.add(id); session.setAttribute("cart", list); System.out.println(list.toString()); response.getWriter().println("已加入购物车<br/>" + "<a href='"+request.getContextPath()+"/home'>继续购物</a><br/>" + "<a href='"+request.getContextPath()+"/show/cart'>查看购物车</a><br/>"); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} |
ShowCartSevlet页面
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@WebServlet({ "/ShowCartServlet", "/show/cart" })public class ShowCartServlet extends HttpServlet { private static final long serialVersionUID = 1L; public ShowCartServlet() { super(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); PrintWriter out = response.getWriter(); List<String> list = (List<String>)request.getSession().getAttribute("cart"); if(list!=null){ out.print("你的购物清单：<br/>"); for (String string : list) { out.println(DBUtils.findById(string)+"<br/>"); } out.println("<br/><a href='"+request.getContextPath()+"/home'>继续购物</a><br/>"); }else{ out.println("你还没有将商品添加到购物车<br/>" + "<a href='"+request.getContextPath()+"/home'>返回商品列表</a><br/>"); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); }} |
DBUtils：存储着商品信息
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public class DBUtils { private static Map<String,String> map = new HashMap<>(); static{ map.put("1", "人类简史"); map.put("2", "未来简史"); map.put("3", "世界简史"); map.put("4", "时间简史"); } public static String findById(String id){ return map.get(id); }} |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：http://blog.csdn.net/qq_33689414/article/details/59102339
