iqdiscoitemshandler.java

基于Jabber协议的即时消息服务器

/**
 * $RCSfile$
 * $Revision: 1701 $
 * $Date: 2005-07-26 02:23:45 -0300 (Tue, 26 Jul 2005) $
 *
 * Copyright (C) 2004 Jive Software. All rights reserved.
 *
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
 */

package org.jivesoftware.wildfire.disco;

import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.QName;
import org.jivesoftware.wildfire.IQHandlerInfo;
import org.jivesoftware.wildfire.Session;
import org.jivesoftware.wildfire.SessionManager;
import org.jivesoftware.wildfire.XMPPServer;
import org.jivesoftware.wildfire.auth.UnauthorizedException;
import org.jivesoftware.wildfire.handler.IQHandler;
import org.jivesoftware.wildfire.roster.RosterItem;
import org.jivesoftware.wildfire.user.User;
import org.jivesoftware.wildfire.user.UserManager;
import org.jivesoftware.wildfire.user.UserNotFoundException;
import org.xmpp.packet.IQ;
import org.xmpp.packet.JID;
import org.xmpp.packet.PacketError;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

/**
 * IQDiscoItemsHandler is responsible for handling disco#items requests. This class holds a map with
 * the main entities and the associated DiscoItemsProvider. We are considering the host of the
 * recipient JIDs as main entities. It's the DiscoItemsProvider responsibility to provide the items
 * associated with the JID's name together with any possible requested node.<p>
 * <p/>
 * For example, let's have in the entities map the following entries: "localhost" and
 * "conference.localhost". Associated with each entry we have different DiscoItemsProvider. Now we
 * receive a disco#items request for the following JID: "[e-mail]" which is a disco
 * request for a MUC room. So IQDiscoItemsHandler will look for the DiscoItemsProvider associated
 * with the JID's host which in this case is "conference.localhost". Once we have located the
 * provider we will delegate to the provider the responsibility to provide the items specific to
 * the JID's name which in this case is "room". Depending on the implementation, the items could be
 * the list of existing occupants if that information is publicly available. Finally, after we have
 * collected all the items provided by the provider we will add them to the reply. On the other
 * hand, if no provider was found or the provider has no information for the requested name/node
 * then a not-found error will be returned.<p>
 * <p/>
 * Publishing of client items is still not supported.
 *
 * @author Gaston Dombiak
 */
public class IQDiscoItemsHandler extends IQHandler implements ServerFeaturesProvider {

    private Map<String,DiscoItemsProvider> entities = new HashMap<String,DiscoItemsProvider>();
    private List<Element> serverItems = new ArrayList<Element>();
    private Map<String, DiscoItemsProvider> serverNodeProviders =
            new ConcurrentHashMap<String, DiscoItemsProvider>();
    private IQHandlerInfo info;
    private IQDiscoInfoHandler infoHandler;

    public IQDiscoItemsHandler() {
        super("XMPP Disco Items Handler");
        info = new IQHandlerInfo("query", "http://jabber.org/protocol/disco#items");
    }

    public IQHandlerInfo getInfo() {
        return info;
    }

    public IQ handleIQ(IQ packet) throws UnauthorizedException {
        // TODO Let configure an authorization policy (ACL?). Currently anyone can discover items.
        
        // Create a copy of the sent pack that will be used as the reply
        // we only need to add the requested items to the reply if any otherwise add 
        // a not found error
        IQ reply = IQ.createResultIQ(packet);
        
        // TODO Implement publishing client items
        if (IQ.Type.set == packet.getType()) {
            reply.setChildElement(packet.getChildElement().createCopy());
            reply.setError(PacketError.Condition.feature_not_implemented);
            return reply;
        }

        // Look for a DiscoItemsProvider associated with the requested entity.
        // We consider the host of the recipient JID of the packet as the entity. It's the 
        // DiscoItemsProvider responsibility to provide the items associated with the JID's name  
        // together with any possible requested node.  
        DiscoItemsProvider itemsProvider = getProvider(packet.getTo() == null ?
                XMPPServer.getInstance().getServerInfo().getName() : packet.getTo().getDomain());
        if (itemsProvider != null) {
            // Get the JID's name
            String name = packet.getTo() == null ? null : packet.getTo().getNode();
            if (name == null || name.trim().length() == 0) {
                name = null;
            }
            // Get the requested node
            Element iq = packet.getChildElement();
            String node = iq.attributeValue("node");

            // Check if we have items associated with the requested name and node
            Iterator<Element> itemsItr = itemsProvider.getItems(name, node, packet.getFrom());
            if (itemsItr != null) {
                reply.setChildElement(iq.createCopy());
                Element queryElement = reply.getChildElement();

                // Add to the reply all the items provided by the DiscoItemsProvider
                Element item;
                while (itemsItr.hasNext()) {
                    item = itemsItr.next();
                    item.setQName(new QName(item.getName(), queryElement.getNamespace()));
                    queryElement.add(item.createCopy());
                }
            }
            else {
                // If the DiscoItemsProvider has no items for the requested name and node 
                // then answer a not found error
                reply.setChildElement(packet.getChildElement().createCopy());
                reply.setError(PacketError.Condition.item_not_found);
            }
        }
        else {
            // If we didn't find a DiscoItemsProvider then answer a not found error
            reply.setChildElement(packet.getChildElement().createCopy());
            reply.setError(PacketError.Condition.item_not_found);
        }

        return reply;
    }

    /**
     * Returns the DiscoItemsProvider responsible for providing the items related to a given entity
     * or null if none was found.
     *
     * @param name the name of the identity.
     * @return the DiscoItemsProvider responsible for providing the items related to a given entity
     *         or null if none was found.
     */
    private DiscoItemsProvider getProvider(String name) {
        return entities.get(name);
    }

    /**
     * Sets that a given DiscoItemsProvider will provide the items related to a given entity. This
     * message must be used when new modules (e.g. MUC) are implemented and need to provide
     * the items related to them.
     *
     * @param name     the name of the entity.
     * @param provider the DiscoItemsProvider that will provide the entity's items.
     */
    protected void setProvider(String name, DiscoItemsProvider provider) {
        entities.put(name, provider);
    }

    /**
     * Removes the DiscoItemsProvider related to a given entity.
     *
     * @param name the name of the entity.
     */
    protected void removeProvider(String name) {
        entities.remove(name);
    }

    /**
     * Adds the items provided by the new service that implements the ServerItemsProvider
     * interface. This information will be used whenever a disco for items is made against
     * the server (i.e. the packet's target is the server).
     * Example of item is: &lt;item jid='conference.localhost' name='Public chatrooms'/&gt;
     *
     * @param provider the ServerItemsProvider that provides new server items.
     */