jsp电子商务购物车之五 数据库存储篇2

//ChangeCartCountServlet 使用ajax实现数量，增加或减少;

package com.cart.web;

import java.io.IOException;
import java.io.PrintWriter;
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.cart.dao.BookDao;
import com.cart.dao.impl.BookDaoImpl;
import com.cart.entity.Book;
import com.cart.entity.CartItem;
import com.cart.entity.Userinfo;
import com.cart.service.CartService;

public class ChangeCartCountServlet extends HttpServlet {
  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    this.doPost(req, resp);
  }

  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {

    resp.setContentType("text/html;charset=utf-8");
    PrintWriter out = resp.getWriter();

    int bookid = Integer.parseInt(req.getParameter("bookid"));
    int count = Integer.parseInt(req.getParameter("count"));
    CartService cartService=new CartService();
    Userinfo userinfo=(Userinfo)req.getSession().getAttribute("userinfo");
    int uid=userinfo.getId();//获得当前用户id编号；

    CartItem cartItem=cartService.findCartItemById(uid,bookid);
    if(cartItem.getCount()<count){//如果根据总数量小于你增加的总数量，则不能购物，业务正确;
      out.print("false");
      return;
    }

    Map<Integer,CartItem> cart = (Map<Integer,CartItem>)req.getSession().getAttribute("cart");
    int result=-1;
    if(cart!=null){
      cartItem = cart.get(bookid); //获得购物车项   
      cartItem.setCount(count);
      cart.put(bookid, cartItem);

      result=cartService.updateCartItemCount(cartItem);
    }
    if(result>0){
      out.print("true");
    }else{
      out.print("false");
    }

    out.flush();
    out.close();
  }
}

package com.cart.web;


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

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

import com.cart.entity.CartItem;
import com.cart.entity.Userinfo;
import com.cart.service.CartService;

public class ShowBookServlet extends HttpServlet {
  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    HttpSession session=req.getSession();
    Userinfo user=(Userinfo)session.getAttribute("userinfo");
    int uid=user.getId();
    CartService cartService=new CartService();
    Map<Integer,CartItem> cart = cartService.getCartItem(uid);

    session.setAttribute("cart", cart); //加入session用jstl读取；
    resp.sendRedirect("show_cart.jsp");

  }
  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    this.doGet(req, resp);
  }
}

package com.cart.web;


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

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

import com.cart.entity.Book;
import com.cart.entity.CartItem;
import com.cart.entity.Userinfo;
import com.cart.service.CartService;

public class DeleteCartServlet extends HttpServlet {
  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    HttpSession session=req.getSession();
    Userinfo user=(Userinfo)session.getAttribute("userinfo");
    int uid=user.getId();
    int bookid = Integer.parseInt(req.getParameter("bookid"));

        Map<Integer,CartItem> cart = (Map<Integer,CartItem>)req.getSession().getAttribute("cart");
        // 根据key(bookid)删除
        cart.remove(bookid);
        //需要根据carService进行操作;
        CartService cartService=new CartService();
        cartService.deletecartItem(uid, bookid);

        req.getSession().setAttribute("cart", cart);

        resp.sendRedirect("show_cart.jsp");
  }
  @Override
  protected void doPost(HttpServletRequest req, HttpServletResponse resp)
      throws ServletException, IOException {
    this.doGet(req, resp);
  }
}