jforum.java

一个论坛程序的简单实现

/*
 * Copyright (c) 2003, Rafael Steil
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met:
 * 
 * 1) Redistributions of source code must retain the above 
 * copyright notice, this list of conditions and the 
 * following  disclaimer.
 * 2)  Redistributions in binary form must reproduce the 
 * above copyright notice, this list of conditions and 
 * the following disclaimer in the documentation and/or 
 * other materials provided with the distribution.
 * 3) Neither the name of "Rafael Steil" nor 
 * the names of its contributors may be used to endorse 
 * or promote products derived from this software without 
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT 
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY 
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, 
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 
 * THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER 
 * IN CONTRACT, STRICT LIABILITY, OR TORT 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE
 * 
 * This file creation date: Mar 3, 2003 / 11:43:35 AM
 * The JForum Project
 * http://www.jforum.net
 */
package net.jforum;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Date;
import java.util.HashMap;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.jforum.entities.User;
import net.jforum.entities.UserSession;
import net.jforum.model.DataAccessDriver;
import net.jforum.model.UserSessionModel;
import net.jforum.repository.SecurityRepository;
import net.jforum.util.I18n;
import net.jforum.util.MD5;
import net.jforum.util.preferences.ConfigKeys;
import net.jforum.util.preferences.SystemGlobals;
import freemarker.template.Template;

/**
 * Front Controller.
 * 
 * @author Rafael Steil
 * @version $Id: JForum.java,v 1.43 2004/11/07 14:01:42 rafaelsteil Exp $
 */
public class JForum extends JForumCommonServlet 
{
	private static boolean isDatabaseUp; 
	
	private void startDatabase() throws Exception
	{
		DBConnection.getImplementation().init();
		
		// If init() fails, the above code will not
		// be executed, soh is safe to have it this way
		isDatabaseUp = true;
	}
	
	public void init(ServletConfig config) throws ServletException
	{
		super.init(config);
		
		try {
			this.startDatabase();
		}
		catch (Exception e) {
			// we don't care about the exception here
			// to not invalidate the context
			isDatabaseUp = false;
		}
	}
	
	private void setAnonymousUserSession(UserSession userSession)
	{
		userSession.setStartTime(new Date(System.currentTimeMillis()));
		userSession.setLastVisit(new Date(System.currentTimeMillis()));
		userSession.setUserId(SystemGlobals.getIntValue(ConfigKeys.ANONYMOUS_USER_ID));
		userSession.setSessionId(JForum.getRequest().getSession().getId());
		
		SessionFacade.setAttribute("logged", "0");
	}
	
	private void checkCookies() throws Exception
	{
		if (SessionFacade.getUserSession() == null) {
			UserSession userSession = new UserSession();
			userSession.setSessionId(JForum.getRequest().getSession().getId());

			String cookieName = SystemGlobals.getValue(ConfigKeys.COOKIE_NAME_DATA);
			
			Cookie cookie = JForum.getCookie(cookieName);
			Cookie hashCookie = JForum.getCookie(SystemGlobals.getValue(ConfigKeys.COOKIE_USER_HASH));
			Cookie autoLoginCookie = JForum.getCookie(SystemGlobals.getValue(ConfigKeys.COOKIE_AUTO_LOGIN));
			
			// If we don't have any cookie yet, then we should set it with the default values
			if (hashCookie == null || cookie == null 
					|| cookie.getValue().equals(SystemGlobals.getValue(ConfigKeys.ANONYMOUS_USER_ID))
					|| (autoLoginCookie == null || !"1".equals(autoLoginCookie.getValue()))) {
				this.setAnonymousUserSession(userSession);
			}
			else {
				String uid = cookie.getValue();
				String uidHash = hashCookie.getValue();
				
				String securityHash = SystemGlobals.getValue(ConfigKeys.USER_HASH_SEQUENCE);
				
				if ((uid != null && !uid.equals(""))
						&& (securityHash != null && !securityHash.equals(""))
						&& (MD5.crypt(securityHash + uid).equals(uidHash))) {
					int userId = Integer.parseInt(uid);
					userSession.setUserId(userId);

					User user = DataAccessDriver.getInstance().newUserModel().selectById(userId);
					UserSessionModel sm = DataAccessDriver.getInstance().newUserSessionModel();

					UserSession tmpUs = sm.selectById(userSession, JForum.getConnection());
					if (tmpUs == null) {
						userSession.setStartTime(new Date(System.currentTimeMillis()));
						userSession.setLastVisit(new Date(System.currentTimeMillis()));
						sm.add(userSession, JForum.getConnection());
					}
					else {
						// Update last visit and session start time
						userSession.setLastVisit(new Date(tmpUs.getStartTime().getTime() + tmpUs.getSessionTime()));
						userSession.setStartTime(new Date(System.currentTimeMillis()));
					}
					
					userSession.setPrivateMessages(user.getPrivateMessagesCount());
					userSession.setUsername(user.getUsername());

					// If the execution point is here, then the user
					// has choosed "autoLogin"
					userSession.setAutoLogin(true);
					SessionFacade.setAttribute("logged", "1");
					
					userSession.setLang(user.getLang());
					if (user.getLang() != null && !user.getLang().equals("") && !I18n.contains(user.getLang())) {
						I18n.load(user.getLang());
					}
				}
				else {
					this.setAnonymousUserSession(userSession);
				}
			}
			
			SessionFacade.add(userSession);
			SessionFacade.setAttribute("topics_tracking", new HashMap());
		}
		else {
			SessionFacade.getUserSession().updateSessionTime();
		}
	}
	
	protected void setupTemplateContext()
	{
		JForum.getContext().put("contextPath", JForum.getRequest().getContextPath());
		JForum.getContext().put("serverName", JForum.getRequest().getServerName());
		JForum.getContext().put("templateName", SystemGlobals.getValue(ConfigKeys.TEMPLATE_NAME));
		JForum.getContext().put("extension", SystemGlobals.getValue(ConfigKeys.SERVLET_EXTENSION));
		JForum.getContext().put("serverPort", Integer.toString(JForum.getRequest().getServerPort()));
		JForum.getContext().put("I18n", I18n.getInstance());
		JForum.getContext().put("JForumContext", new JForumContext(JForum.getRequest().getContextPath(), 
				SystemGlobals.getValue(ConfigKeys.SERVLET_EXTENSION), getResponse()));
		JForum.getContext().put("version", SystemGlobals.getValue(ConfigKeys.VERSION));
		JForum.getContext().put("forumTitle", SystemGlobals.getValue(ConfigKeys.FORUM_PAGE_TITLE));
		JForum.getContext().put("pageTitle", SystemGlobals.getValue(ConfigKeys.FORUM_PAGE_TITLE));
		JForum.getContext().put("metaKeywords", SystemGlobals.getValue(ConfigKeys.FORUM_PAGE_METATAG_KEYWORDS));
		JForum.getContext().put("metaDescription", SystemGlobals.getValue(ConfigKeys.FORUM_PAGE_METATAG_DESCRIPTION));
		JForum.getContext().put("forumLink", SystemGlobals.getValue(ConfigKeys.FORUM_LINK));
		JForum.getContext().put("encoding", SystemGlobals.getValue(ConfigKeys.ENCODING));
	}
	
	public void service(HttpServletRequest req, HttpServletResponse response) throws IOException, ServletException
	{
		BufferedWriter out = null;
		
		try {
			// Initializes thread local data
			DataHolder dataHolder = new DataHolder();
			localData.set(dataHolder);

			String encoding = SystemGlobals.getValue(ConfigKeys.ENCODING);
			req.setCharacterEncoding(encoding);
			
			// Request
			ActionServletRequest request = new ActionServletRequest(req);
			request.setCharacterEncoding(encoding);

			dataHolder.setResponse(response);
			dataHolder.setRequest(request);
			
			if (!isDatabaseUp) {
				this.startDatabase();
			}
			
			
			if (isDatabaseUp) {
				dataHolder.setConnection(DBConnection.getImplementation().getConnection());
			}
			
			localData.set(dataHolder);
			
			// Context
			this.setupTemplateContext();
			
			// Verify cookies
			this.checkCookies();
			
			boolean logged = false;
			if ("1".equals(SessionFacade.getAttribute("logged"))) {
				logged = true;
			}
			
			JForum.getContext().put("logged", logged);
			
			// Process security data
			SecurityRepository.load(SessionFacade.getUserSession().getUserId());

			String module = request.getModule();
			
			// Gets the module class name
			String moduleClass = this.getModuleClass(module);
			
			JForum.getContext().put("moduleName", module);
			JForum.getContext().put("action", JForum.getRequest().getAction());
			
			JForum.getContext().put("securityHash", MD5.crypt(JForum.getRequest().getSession().getId()));
			JForum.getContext().put("session", SessionFacade.getUserSession());
			
			out = new BufferedWriter(new OutputStreamWriter(response.getOutputStream(), encoding));
			if (moduleClass != null) {
				// Here we go, baby
				Command c = (Command)Class.forName(moduleClass).newInstance();
				Template template = c.process();

				DataHolder dh = (DataHolder)localData.get();
				if (dh.getRedirectTo() == null) {
					String contentType = dh.getContentType();
					if (contentType == null) {
						contentType = "text/html";
					}
					
					response.setContentType(contentType + ";charset=" + encoding);

					template.process(JForum.getContext(), out);
					out.flush();
				}
			}
		}
		catch (Exception e) {
			response.setContentType("text/html");
			if (out != null) {
				new ForumException(e, out);
				out.flush();
			}
			else {
				new ForumException(e, new BufferedWriter(new OutputStreamWriter(response.getOutputStream())));
			}
		}
		finally {
			try {
				if (JForum.getConnection() != null) {
					DBConnection.getImplementation().releaseConnection(JForum.getConnection());
				}
			}
			catch (Exception e) {
				new ForumException(e);
				e.printStackTrace();
			}
		}
		
		String redirectTo = ((DataHolder)localData.get()).getRedirectTo();
		if (redirectTo != null) {
			JForum.getResponse().sendRedirect(redirectTo);
		}
		
		localData.set(null);
	}
	
	/** 
	 * @see javax.servlet.GenericServlet#destroy()
	 */
	public void destroy() {
		super.destroy();
		System.out.println("destroying...");
		
		try {
			DBConnection.getImplementation().realReleaseAllConnections();
		}
		catch (Exception e) {}
	}
}