preindex.java

java web开发宝典源代码

package com.yxq.servlet;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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.yxq.bean.SingleObject;

public class PreIndex extends HttpServlet {
    private Map havemap=new HashMap();
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request,response);
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		HttpSession session=request.getSession();
		List currentlist=(ArrayList)session.getAttribute("currentlist");
		if(currentlist==null||currentlist.size()==0){
			System.out.println("没有记录显示！");
		}
		else{
			Map carmap=(HashMap)session.getAttribute("carmap");
			for(int i=0;i<currentlist.size();i++){
				SingleObject currentsingle=(SingleObject)currentlist.get(i);
				Object key=currentsingle.getId();
				synchronized(havemap){
					if(!havemap.containsKey(key)){
						havemap.put(key,currentsingle.getHave());
					}
					
					if((Integer)havemap.get(key)<=0){
						if(carmap==null||carmap.size()==0||!carmap.containsKey(key))
							currentsingle.setBuyN(0);
						else{
							SingleObject carsingle=(SingleObject)carmap.get(key);
							currentsingle.setBuyN(carsingle.getBuyN());
						}
						currentsingle.setHave(0);
						currentsingle.setMessage("库存已空！");
					}
					else{
						currentsingle.setMessage("");
						if(carmap==null||carmap.size()==0||!carmap.containsKey(key)){
							currentsingle.setBuyN(0);
							currentsingle.setHave((Integer)havemap.get(key));
						}
						else{
							SingleObject carsingle=(SingleObject)carmap.get(key);
							currentsingle.setBuyN(carsingle.getBuyN());
							currentsingle.setHave(carsingle.getHave());
						}
					}
				    currentlist.set(i,currentsingle);					
				}//synchronized
			}//for
            session.getServletContext().setAttribute("havemap",havemap);
			session.setAttribute("currentlist",currentlist);
		}
		RequestDispatcher rd=request.getRequestDispatcher("/templet.jsp");
		rd.forward(request,response);
	}
}