carbo.java

模拟网上购物系统

package business;

import java.util.ArrayList;
import java.util.Iterator;

import javax.servlet.http.HttpSession;

import vo.CarVO;
import vo.shopVO;

public class CarBO {
	
	public void addPro(HttpSession session,shopVO vo)
	{
         //取得session中的信息
		CarVO mycar = (CarVO)session.getAttribute("car");
		
		if(mycar == null)//第一次购物,购物车被清空
		{
			CarVO car = new CarVO();
			
			ArrayList al = new ArrayList();
			al.add(vo);
			car.setAl(al);
			
            //写入session对象
			session.setAttribute("car", car);
		}
		else
		{
			if(isBuy(session,vo))
			{
				modify(session,vo);
			}
			else
			{
				ArrayList al = mycar.getAl();
				al.add(vo);
			}
		}
		
	}
	
	////判断是否已经购买了该商品
	public boolean isBuy(HttpSession session,shopVO vo)
	{
		boolean isbuy = false;
		CarVO car = (CarVO)session.getAttribute("car");
		ArrayList al = car.getAl();
		Iterator it = al.iterator();
		while(it.hasNext())
		{
			shopVO mypo = (shopVO)it.next();
			if(mypo.getProid() == vo.getProid())
			{
				isbuy = true;
				break;
			}
		}
		return isbuy;
	}
	
	//修改重复的商品
	public void modify(HttpSession session,shopVO po)
	{
		CarVO car = (CarVO)session.getAttribute("car");
		ArrayList al = car.getAl();
		Iterator it = al.iterator();
		while(it.hasNext())
		{
			shopVO mypo = (shopVO)it.next();
			if(mypo.getProid() == po.getProid())
			{
			    int temp = mypo.getNum()+po.getNum();
			    mypo.setNum(temp);
			}
		
	    }
	}
	
	//清空
	public void clean(HttpSession session)
	{
		CarVO car = (CarVO)session.getAttribute("car");
		if(car != null)
		{
			session.removeAttribute("car");
		}
		
		
	}
	
	//取消商品
	public void delete(HttpSession session,shopVO po)
	{
		CarVO car = (CarVO)session.getAttribute("car");
		
		if(car != null)
		{
			ArrayList al = car.getAl();
			Iterator it = al.iterator();
			
			for(int i=0;i<al.size();i++)
			{
				shopVO mypo = (shopVO)al.get(i);
				if(mypo.getProid() == po.getProid())
				{
					al.remove(i);
				}
			}
		}
	}

}