buybookservlet.java

servlet实现网上书店查询

package com.ghy.bookstore.order.web;

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

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.ghy.bookstore.book.model.BookVO;
import com.ghy.bookstore.order.model.OrderItem;
import com.ghy.bookstore.service.BookStoreService;
import com.ghy.bookstore.service.BookStoreServiceFactory;

public class BuyBookServlet extends HttpServlet {

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

		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("utf-8");
		BookStoreService bsService = BookStoreServiceFactory
				.getBookStoreService();
		String bookid = request.getParameter("bookId");
		HttpSession session = request.getSession();
		OrderItem orderItem = new OrderItem();
		ArrayList list = (ArrayList) session.getAttribute("ShopCart");
		String s;
		
		
		boolean flag = false;
		if(list==null)
			list=new ArrayList();
	    if (list != null) {
			for (int i = 0; i < list.size(); i++) {
				orderItem = (OrderItem) list.get(i);
				if (orderItem.getBookid().equals(bookid))
				// 如果购物车里面已经存在所要购买的书
				flag = true;
			}
		}

		if (!flag)// 如果购物车不存在所要购买的书
		{
			BookVO book = new BookVO();
			// 如果出异常,跳转到error.jsp页面,输出错误信息,return终止后面代码执行
			try {
				book = bsService.findBookByID(bookid);
	
			} catch (Exception e) {
				response.sendRedirect(request.getContextPath()
						+ "/jsp/error.jsp?message=" + e.getMessage());
				return;
			}

			OrderItem shopcart = new OrderItem();
			shopcart.setBookid(bookid);
			shopcart.setBookname(book.getName());
			shopcart.setPrice(book.getPrice());
			shopcart.setMount(1);
			list.add(shopcart);
			session.setAttribute("ShopCart", list);
			s = "toBookShopCart";
		}
		
		  else 
			  s="toWrong";
		  response.sendRedirect(request.getContextPath()+"/jsp/order/orderitems.jsp");
		 
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

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

}