updateservlet.java

用Mvc做的一个小项目.用Mvc做的一个小项目. 用Mvc做的一个小项目. 用Mvc做的一个小项目.

package discShop;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Map;

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 UpdateServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//获取两个参数，不多说，最简单的一步
		String discId = request.getParameter("discId");
		String discNum = request.getParameter("discNum");
		//书上54页有详细解释
		HttpSession session = request.getSession(false);

		// 取出购物车和添加的唱片并存入Map中
		Map cart = (Map) session.getAttribute("cart");

		// 在购物车中查找存在的唱片
		DiscItemBean cartItem = (DiscItemBean) cart.get(discId);
		// 更新其数量为网页传进来的（即用户输入的）数量
		cartItem.setNum(Integer.parseInt(discNum));
		//并把Map中的对象存入session
		session.setAttribute("cart", cart);
		//跳转页面，转发请求
		request.getRequestDispatcher("discCart.jsp").forward(request, response);
	}


	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//Post调用Get方法
		this.doGet(request, response);
	}

}