cartservlet.java

网上购物源代码

package com.chinaaccpservlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;

import javax.servlet.RequestDispatcher;
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.chinaaccpDao.BookCount;

public class CartServlet extends HttpServlet {

	
	Set s = null;
	HashMap hm = null;  
	HashMap hm2 = new HashMap();
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		request.setCharacterEncoding("utf-8");
		response.setCharacterEncoding("utf-8");
		HttpSession session = request.getSession();
		session.getAttribute("set");
		session.getAttribute("hashmap");
		
		if(session.getAttribute("set")==null)
		{
			s = new HashSet(); //用HashSet实现Set接口
		}
		if(session.getAttribute("hashmap")==null)
		{
			hm = new HashMap(); //创建HashMap用来纪录购买商品的数量
		}
		String id = request.getParameter("id");
		String cnt = request.getParameter("cnt");
		String dispage = request.getParameter("dis");
		String cont = null;
		int num = 0;
		PrintWriter out = response.getWriter();
		if(hm.get(id)==null)
		{
			cont="1";
			num = Integer.parseInt(cont);
			hm.put(id, num);
			hm2.put(id, num);
		}
		else
		{
			num = Integer.parseInt(hm.get(id).toString());
			num = num+1;
			hm.put(id, num);
			hm2.put(id, num);
		}
		int cnts = Integer.parseInt(hm.get(id).toString());
		//System.out.println(cnts+"&&&&&*********");
		BookCount bookcnt = new BookCount();
		int cnt2=bookcnt.GetBookCount(id);
		//System.out.println(cnt+"  "+cnt2);
		if(cnt2<cnts)
		{
			hm.put(id, cnt2);
			out.println("<script>");
			out.println("alert('数量已不足');");
			out.println("location.href='DisServlet'");
			out.println("</script>");
			return;
		}
		if(id!=null)
		{
			s.add(id);
		}
		
		session.setAttribute("set", s);
		session.setAttribute("hashmap", hm);
		session.setAttribute("hashmap2", hm2);
		
		
		RequestDispatcher dis = request.getRequestDispatcher(cnt);
		dis.forward(request, response);
		out.flush();
		out.close();
		
	}


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

		this.doGet(request, response);
	}
	
}