Java tutorial
/* * Copyright (C) 2010 Moduad Co., Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ package android.apn.androidpn.server.xmpp.router; import java.util.ArrayList; import java.util.List; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.dom4j.Element; import org.xmpp.packet.IQ; import org.xmpp.packet.JID; import org.xmpp.packet.PacketError; import android.apn.androidpn.server.xmpp.handler.IQAuthHandler; import android.apn.androidpn.server.xmpp.handler.IQHandler; import android.apn.androidpn.server.xmpp.handler.IQRegisterHandler; import android.apn.androidpn.server.xmpp.handler.IQRosterHandler; import android.apn.androidpn.server.xmpp.session.ClientSession; import android.apn.androidpn.server.xmpp.session.Session; import android.apn.androidpn.server.xmpp.session.SessionManager; /** * This class is to route IQ packets to their corresponding handler. * * @author Sehwan Noh (devnoh@gmail.com) */ public class IQRouter { private final Log log = LogFactory.getLog(getClass()); private SessionManager sessionManager; private List<IQHandler> iqHandlers = new ArrayList<IQHandler>(); private Map<String, IQHandler> namespace2Handlers = new ConcurrentHashMap<String, IQHandler>(); /** * Constucts a packet router registering new IQ handlers. */ public IQRouter() { sessionManager = SessionManager.getInstance(); iqHandlers.add(new IQAuthHandler()); iqHandlers.add(new IQRegisterHandler()); iqHandlers.add(new IQRosterHandler()); } /** * Routes the IQ packet based on its namespace. * * @param packet the packet to route */ public void route(IQ packet) { if (packet == null) { throw new NullPointerException(); } JID sender = packet.getFrom(); ClientSession session = sessionManager.getSession(sender); if (session == null || session.getStatus() == Session.STATUS_AUTHENTICATED || ("jabber:iq:auth".equals(packet.getChildElement().getNamespaceURI()) || "jabber:iq:register".equals(packet.getChildElement().getNamespaceURI()) || "urn:ietf:params:xml:ns:xmpp-bind".equals(packet.getChildElement().getNamespaceURI()))) { handle(packet); } else { IQ reply = IQ.createResultIQ(packet); reply.setChildElement(packet.getChildElement().createCopy()); reply.setError(PacketError.Condition.not_authorized); session.process(reply); } } private void handle(IQ packet) { try { Element childElement = packet.getChildElement(); String namespace = null; if (childElement != null) { namespace = childElement.getNamespaceURI(); } if (namespace == null) { if (packet.getType() != IQ.Type.result && packet.getType() != IQ.Type.error) { log.warn("Unknown packet " + packet); } } else { IQHandler handler = getHandler(namespace); if (handler == null) { sendErrorPacket(packet, PacketError.Condition.service_unavailable); } else { handler.process(packet); } } } catch (Exception e) { log.error("Could not route packet", e); Session session = sessionManager.getSession(packet.getFrom()); if (session != null) { IQ reply = IQ.createResultIQ(packet); reply.setError(PacketError.Condition.internal_server_error); session.process(reply); } } } /** * Senda the error packet to the original sender */ private void sendErrorPacket(IQ originalPacket, PacketError.Condition condition) { if (IQ.Type.error == originalPacket.getType()) { log.error("Cannot reply an IQ error to another IQ error: " + originalPacket); return; } IQ reply = IQ.createResultIQ(originalPacket); reply.setChildElement(originalPacket.getChildElement().createCopy()); reply.setError(condition); try { PacketDeliverer.deliver(reply); } catch (Exception e) { // Ignore } } /** * Adds a new IQHandler to the list of registered handler. * * @param handler the IQHandler */ public void addHandler(IQHandler handler) { if (iqHandlers.contains(handler)) { throw new IllegalArgumentException("IQHandler already provided by the server"); } namespace2Handlers.put(handler.getNamespace(), handler); } /** * Removes an IQHandler from the list of registered handler. * * @param handler the IQHandler */ public void removeHandler(IQHandler handler) { if (iqHandlers.contains(handler)) { throw new IllegalArgumentException("Cannot remove an IQHandler provided by the server"); } namespace2Handlers.remove(handler.getNamespace()); } /** * Returns an IQHandler with the given namespace. */ private IQHandler getHandler(String namespace) { IQHandler handler = namespace2Handlers.get(namespace); if (handler == null) { for (IQHandler handlerCandidate : iqHandlers) { if (namespace.equalsIgnoreCase(handlerCandidate.getNamespace())) { handler = handlerCandidate; namespace2Handlers.put(namespace, handler); break; } } } return handler; } }