bookingservlet.java

Java程序设计高级教程（第三版）

package com.nearhills.servlets;

import java.io.IOException;
import java.util.Enumeration;

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

import com.nearhills.ClubMember;
import com.nearhills.NoSessionException;
import com.nearhills.SkierInfo;

/**
 * @version 	1.0
 * @author
 */
public class BookingServlet extends HttpServlet {
	/**
	* @see javax.servlet.http.HttpServlet#void (
	*   javax.servlet.http.HttpServletRequest, 
	*   javax.servlet.http.HttpServletResponse)
	*/
	public void doGet(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
		try {
			HttpSession session = req.getSession(false);
			if (session == null) {
				throw new NoSessionException(
					"No session: have you registered " + "or Logged in?");
			}
			Cookie[] cookies = req.getCookies();
			req.setAttribute("new", "no");
			for (int i = 0; i < cookies.length; i++) {
				if (cookies[i].getName().equals("NewMember")
					&& cookies[i].getValue().equals("yes")) {
					resp.addCookie(new Cookie("NewMember", "no"));
					req.setAttribute("new", "yes");
					break;
				}
			}
			RequestDispatcher rd =
				getServletContext().getRequestDispatcher("/bookTrips.jsp");
			rd.forward(req, resp);
		} catch (Exception e) {
			req.setAttribute("exception", e);
			RequestDispatcher rd =
				getServletContext().getRequestDispatcher("/errorReport.jsp");
			rd.forward(req, resp);
		}

	}

	/**
	* @see javax.servlet.http.HttpServlet#void (javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
	*/
	public void doPost(HttpServletRequest req, HttpServletResponse resp)
		throws ServletException, IOException {
		try {
			if (!req.isRequestedSessionIdValid()) {
				throw new NoSessionException("This http request has no valid session.");
			}
			HttpSession session = req.getSession();
			ClubMember skier = (ClubMember) session.getAttribute("member");
			Enumeration e = req.getParameterNames();
			while (e.hasMoreElements()) {
				String action = (String) e.nextElement();
				String button[] = req.getParameterValues(action);
				for (int i = 0; i < button.length; i++) {
					int tripId = Integer.parseInt(button[i]);
					if (action.equals("CANCEL")) {
						skier.cancel(tripId);
					}
					if (action.equals("BOOK")) {
						skier.book(tripId);
					}
				}
			}
			SkierInfo tripInfo = new SkierInfo();
			tripInfo.setId(skier.getId());
			tripInfo.countTrips();
			System.out.println("Trip Booking Complete");
			RequestDispatcher rd =
				getServletContext().getRequestDispatcher("/memberHome.jsp");
			rd.forward(req, resp);
		} catch (Exception e) {
			req.setAttribute("exception", e);
			RequestDispatcher rd =
				getServletContext().getRequestDispatcher("/errorReport.jsp");
			rd.forward(req, resp);
		}
		return;
	}
}