dispshopcarservlet.java

MVC设计+jsp+servlet+sqlserver开发

package com.accp.fan.servlet;

import java.io.IOException;
import java.sql.SQLException;

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.accp.fan.dao.Fooddao;
import com.accp.fan.entity.Food;
import com.accp.fan.entity.Shopcar;

public class DispShopCarServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public DispShopCarServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 * 
	 * This method is called when a form has its tag value method equals to
	 * post.
	 * 
	 * @param request
	 *            the request send by the client to the server
	 * @param response
	 *            the response send by the server to the client
	 * @throws ServletException
	 *             if an error occurred
	 * @throws IOException
	 *             if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String foodID = request.getParameter("foodID");
		int counter = 1;
		try {
			Fooddao dao = new Fooddao();
			Food food = dao.getFoodById(foodID);

			HttpSession session = request.getSession();
			// Shopcar当作是实体类来接收session中的obj
			Shopcar car = (Shopcar) session.getAttribute("car");
			//------第一次订购-------
			if (car == null) {
				food.setCounter(counter);// --第一次订购设置数量为0
				car = new Shopcar();
				car.addItems(food);
				// 即使为空，也要放个空的进去，不然在界面读取时会空指针
				session.setAttribute("car", car);
				response.sendRedirect(request.getContextPath()
						+ "/shopCart.jsp");
			
				
			}
			//------再次订购------
			else {	
				Food item = car.getItem(foodID);// 获取购物车中某个商品
				//-------如果再次订购的是购物车中没有的食物--------
				if(item == null){
					food.setCounter(counter);			
					car.addItems(food);
					// 即使为空，也要放个空的进去，不然在界面读取时会空指针
					session.setAttribute("car", car);
					response.sendRedirect(request.getContextPath()
							+ "/shopCart.jsp");
				}		
				// 如果再次添加的是购物车已经有的食物，需要将数量+1
				
				else if (item.getFoodID().equals(foodID)) {
					food.setCounter(counter + item.getCounter());
					//调用购物车业务类 添加购物车
					car.addItems(food);
					session.setAttribute("car", car);
					response.sendRedirect(request.getContextPath()
							+ "/shopCart.jsp");
				}
				
			}
			
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

	/**
	 * Initialization of the servlet. <br>
	 * 
	 * @throws ServletException
	 *             if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}