carservlet.java

用jsp和servlet技术运用MVC模式做的购物车小系统源码

package com.hygj.servlet;

import java.io.IOException;
import java.util.Hashtable;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class CarServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public CarServlet() {
		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 {
		//获得参数信息
		String productId=request.getParameter("productId");
		String shuliang=request.getParameter("shuliang");
		//获得session
		HttpSession session=request.getSession(true);
		//获得购物车对象
		Hashtable car=(Hashtable)session.getAttribute("car");
		//判断购物车是否存在
		if(car==null){
			//新建购物车
			car=new Hashtable();
		}
		//把新购买的信息添加到购物车中
		car.put(productId, shuliang);
		//更新session。把新的购物车存回去
		session.setAttribute("car",car);
		//页面转到购物车显示页面进行处理
		response.sendRedirect("showCar.jsp");
	}

	/**
	 * 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 {

		this.doGet(request, response);
	}

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

}