carservlet.java

一套购物车项目。电子商务系统。实现了前台和后台的业务逻辑。

package com.softfz.jn0708.servlet;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
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.softfz.jn0708.bean.ItemBean;
import com.softfz.jn0708.dao.ItemDAO;
import com.softfz.jn0708.util.StrUtil;

/**
 * 购物车Servlet
 * @author student
 *
 */
public class CarServlet extends HttpServlet {

	
	/**
	 * 
	 */
	private static final long serialVersionUID = 7206100069748340795L;
	
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doPost(request,response);
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String task = request.getParameter("task");
		if(task!=null&&task.equals("add")){
			doadd(request,response);			
		}else if(task!=null&&task.equals("del")){
			String itemid = request.getParameter("itemid");
			HttpSession session  = request.getSession();
			List list = (List)session.getAttribute("car");
			if(list!=null){
				for (int i=0;i<list.size();i++) {
					ItemBean element = (ItemBean)list.get(i);
					if(String.valueOf(element.getItemid()).equals(itemid)){
						list.remove(i);
						break;
					}					
				}
			}
		}else if(task!=null&&task.equals("update")){
			String itemid = request.getParameter("itemid");
			String quantity = request.getParameter("quantity");
			HttpSession session  = request.getSession();
			List list = (List)session.getAttribute("car");
			if(list!=null){
				for (int i=0;i<list.size();i++) {
					ItemBean element = (ItemBean) list.get(i);
					if(String.valueOf(element.getItemid()).equals(itemid)){
						element.setQuantity(quantity);
						break;
					}					
				}
			}
		}
		else if(task!=null&&task.equals("clear")){
			HttpSession session  = request.getSession();
			List list = (List)session.getAttribute("car");
			if(list!=null){
				list.removeAll(list);										

			}
		}
		
		String contextPath = request.getContextPath();
		response.sendRedirect(contextPath+"/car/car.jsp");		
	}
	/**
	 * 添加商品信息到购物车
	 * @param request
	 * @param response
	 * @throws IOException
	 */
	private void doadd(HttpServletRequest request, HttpServletResponse response) throws IOException {
		
		boolean flag = false;
		String itemid = request.getParameter("itemid");	

		ItemDAO itemsdao = new ItemDAO();		
		ItemBean bean  = itemsdao.getItemById(itemid);		
		HttpSession session = request.getSession();
		List list = (List)session.getAttribute("car");

		if(list==null){
			list = new ArrayList();
			list.add(bean);			
			session.setAttribute("car",list);
		}			
			Iterator iter = list.iterator();		
			while(iter.hasNext()) {
				ItemBean element = (ItemBean)iter.next();
				if(String.valueOf(element.getItemid()).trim().equals(itemid)){
					element.setQuantity(String.valueOf(StrUtil.parseInt(element.getQuantity().trim())+1));
					flag = true;					
					break;
				}						
			}
			

		if(!flag){
			bean.setQuantity("1");
			list.add(bean);
		}
	}

}