Ajax processing for modifying the number of shopping items books

First, cart.jsp page

<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding=" Utf-8 "%> <%@ taglib uri=" Http://java.sun.com/jsp/jstl/core "prefix=" C "%> <! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >
Ii. Modification of Cartservlet
Package Com.atguigu.bookstore.servlet.client;import Com.atguigu.bookstore.bean.book;import Com.atguigu.bookstore.fun.cart;import Com.atguigu.bookstore.service.impl.bookserviceimpl;import Com.atguigu.bookstore.service.impl.cartserviceimpl;import Com.atguigu.bookstore.service.inter.BookService; Import Com.atguigu.bookstore.service.inter.cartservice;import Com.atguigu.bookstore.servlet.baseservlet;import Com.atguigu.bookstore.utils.webutils;import Com.google.gson.gson;import Java.io.ioexception;import Java.util.hashmap;import Java.util.map;import Javax.servlet.servletexception;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;public class CartServlet Extends Baseservlet {private static final long serialversionuid = 1L; Cartservice cartservice=new Cartserviceimpl (); Bookservice bookservice=new Bookserviceimpl ();p rotected void Add (HttpServletRequest request, HttpServletResponse Response) throws Servletexception, IOException {System.out.println ("Add ....")); String BookID = Request.getparameter ("BookID"); Book book = Bookservice.getbookbyid (BookID); Cart cart = Webutils.getcart (request); Cartservice.add (book, cart);//To get such data {"BookName": "Java", "TotalCount": 2} How? String bookname = Book.getbookname (), int totalcount = Cart.gettotalcount ();//Use Gson to get the above type of data, but need a source, this only map and// SRC is a generic object or Map object, which can only be used in the Map object, because if it is a generic object, the need for a class to contain these 2 attributes, but also to redefine the class, it is troublesome//and SRC is a Map object does not need to redefine the class, map<string, Object>map=new hashmap<string, object> () map.put ("BookName", bookname); The time to fetch data is data.bookname;map.put ("TotalCount", totalcount); String jsonstr=new Gson (). ToJson (map); Response.setcontenttype ("Text/json;charset=utf-8"); Response.getwriter (). Write (JSONSTR);} protected void Delete (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { System.out.println ("Delete ..."); String BookID = Request.getparameter ("BookID"); Cart cart = Webutils.getcart (Request), Cartservice.deleteitem (Integer.parseint (bookid), cart); Webutils.myforwaRD (Request, response, "/client/book/cart.jsp");} protected void Update (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { SYSTEM.OUT.PRINTLN ("Update ...."); String count = Request.getparameter ("Count"); String bookId = Request.getparameter ("BookId"); Map<string, Object>map=cartservice.updatecount (Integer.parseint (bookId), Integer.parseint (count), Webutils.getcart (Request));//webutils.myforward (Request, Response, "/client/book/cart.jsp"); Not in this way//to return the data type: {count:2,itemprice:20,totalcount:5,totalprice:50}, then how to get it? You can change the Updatecount method so that it returns a map collection of string json = new Gson (). ToJson (map); Response.setcontenttype ("Text/json;charset=utf-8 "); Response.getwriter (). write (JSON);} protected void Clear (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException { System.out.println ("clear ..."); Cartservice.clear (Webutils.getcart (request)); Webutils.myforward (Request, Response, "/client/book/cart.jsp");}}

Third, modify the Cartserviceimpl
<span style= "White-space:pre" ></span> @Overridepublic map<string, object> updatecount (int BookId, int count, cart cart) {map<string, object>map=new hashmap<string, object> (); Cartitem Cartitem = Cart.getmap (). get (BookId); Cartitem.setcount (count);//{count:2,itemprice:20,totalcount:5, Totalprice:50},map.put ("Count", Count), Map.put ("Itemprice", Cartitem.getitemprice ()), Map.put ("TotalCount", Cart.gettotalcount ()); Map.put ("Totalprice", Cart.gettotalprice ()); return map;}


Ajax processing for modifying the number of shopping items books