您已经将 加入到购物车中,购物车中有 本书,总价格是 


 java 加入购物车
 ajax 加入购物车
 jquery 加入购物车

 public class AddToCartServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1:获取请求参数 id(bookName),price String bookName =request.getParameter("id"); int price =Integer.parseInt(request.getParameter("price")); //2：获取购物车对象，在session中 ShoppingCart sc=(ShoppingCart) request.getSession().getAttribute("sc"); if(sc==null){ sc=new ShoppingCart(); request.getSession().setAttribute("sc",sc); } //3；将点击的对象加入到购物车中 sc.addToCart(bookName, price); //4:准备响应的Json对象:{""bookName"":"totalBookNumber","totalMoney" } //若从服务器端返回json对象，则属性名必须使用双引号！！ StringBuilder sBuilder=new StringBuilder(); sBuilder.append("{") .append("\"bookName\":\""+bookName+"\"") .append(",") .append("\"totalBookNumber\":\""+sc.getTotalBookNumber()+"\"") .append(",") .append("\"totalMoney\":\""+sc.getTotalMoney()+"\"") .append("}"); //响应json请求 response.setContentType("text/javascript"); response.getWriter().print(sBuilder.toString()); } } 上述中的用StringBuilder来拼接JSON字符串的方式可以借助第三方开源Jackson来简化实现： String jsonStr=null; ObjectMapper objectMapper=new ObjectMapper(); jsonStr=objectMapper.writeValueAsString(sc);