additemservlet.java

使用jsp+Servlet,采用MVC模式,实现了一典型小型电子商务网站的全过程.包括前台和后台的全部功能.适合于初学者学习使用.

package com.eshop.servlet;

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

import javax.servlet.RequestDispatcher;
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.eshop.service.CartService;
import com.eshop.service.ItemService;
import com.eshop.vo.Cart;
import com.eshop.vo.Item;

public class AddItemServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public AddItemServlet() {
		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 {

		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 {

		response.setContentType("text/html");
		String contextPath=request.getContextPath();
		String itemId=request.getParameter("theItemId");
		HttpSession session=request.getSession();
		String userid=(String) session.getAttribute("userid");
		String password=(String) session.getAttribute("password");
		if(userid==null||userid.equals(null)&&password==null||password.equals(null)){
			response.sendRedirect(contextPath+"/account/login.jsp");	
		}else{
		Item item=new Item();
		ItemService itemService=new ItemService();
		item=itemService.getItemById(itemId);
		CartService cartService=(CartService)session.getAttribute("cartService");
		if(cartService==null){
			 cartService=new CartService();
			session.setAttribute("cartService", cartService);			
		}
		cartService.addItem(item);
		RequestDispatcher dis1=request.getRequestDispatcher("listItem");
		dis1.forward(request, response);

		}

	}

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

}