package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.dao.GoodsDAO;
import com.entity.Goods;
import com.entity.GoodsItem;

public class PutCarServlet extends HttpServlet {

 public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

 response.setContentType("text/html");
 PrintWriter out = response.getWriter();
 
 doPost(request, response);
 }

 public void doPost(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

 response.setContentType("text/html");
 PrintWriter out = response.getWriter();
 //得到編號(hào)
 String id = request.getParameter("goodsID");
 
 //通過編號(hào)得到商品對(duì)象的所有信息
 GoodsDAO dao = new GoodsDAO();
 Goods g = dao.getGoodsByID(id);
 //將商品放入購物車
 
 //map集合 就是購物車
 // map<鍵,值> 商品編號(hào)作為鍵 商品項(xiàng)作為值
 
 //1.判斷是否存在購物車
 //購物車是放在session中的
 //從session去取購物車
 Map<String,GoodsItem> gwc = (Map<String,GoodsItem>)request.getSession().getAttribute("gwc");
 //判斷是否存在
 if(gwc==null){
  //創(chuàng)建購物車
  gwc = new HashMap<String, GoodsItem>();
 }
 
 //將商品項(xiàng)放入購物車
 //put(商品編號(hào),商品項(xiàng)) 向gwc集合中添加數(shù)據(jù)
 //你要想 購物車中是否已存在該商品
 // 說白了 就是在gwc集合中去匹配是否存在這樣一個(gè)商品項(xiàng) ==》去集合中匹配是否存在這樣一個(gè)商品編號(hào)的key
 
 //判斷是否存在商品編號(hào)的鍵
 
 if(gwc.containsKey(id)){
  //存在
  //設(shè)置數(shù)量+1
  
  //通過鍵 獲得值
  //鍵為商品編號(hào) 值為商品項(xiàng) 商品項(xiàng)里面包含商品對(duì)象信息 和數(shù)量信息
  GoodsItem spx = gwc.get(id);
  //得到原來的數(shù)量
  int yldsl = spx.getCount();
  //在原來的數(shù)量上+1
  gwc.get(id).setCount(yldsl+1);
  
//  gwc.get(id).setCount(gwc.get(id).getCount()+1) ;
  
 }else{
  //不存在
  //創(chuàng)建一個(gè)新的商品項(xiàng) 數(shù)量為1
  GoodsItem gi = new GoodsItem(g, 1);
  
  //將此商品項(xiàng)放入gwc
  gwc.put(id, gi);
 }
 
 //將購物車放入session
 request.getSession().setAttribute("gwc", gwc);
 
 //繼續(xù)購物
 response.sendRedirect("index.jsp");
 }

}