/**
* $RCSfile$
* $Revision: 4603 $
* $Date: 2006-07-19 23:24:00 +0400 (Wed, 19 Jul 2006) $
*
* Copyright 2003-2004 Jive Software.
*
* All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smackx;
import org.jivesoftware.smack.*;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.filter.PacketIDFilter;
import org.jivesoftware.smack.filter.PacketTypeFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smack.packet.XMPPError;
import org.jivesoftware.smackx.packet.DiscoverInfo;
import org.jivesoftware.smackx.packet.DiscoverItems;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
/**
* Manages discovery of services in XMPP entities. This class provides:
* <ol>
* <li>A registry of supported features in this XMPP entity.
* <li>Automatic response when this XMPP entity is queried for information.
* <li>Ability to discover items and information of remote XMPP entities.
* <li>Ability to publish publicly available items.
* </ol>
*
* @author Gaston Dombiak
*/
public class ServiceDiscoveryManager {
private static String identityName = "Smack";
private static String identityType = "pc";
private static Map<XMPPConnection, ServiceDiscoveryManager> instances =
new ConcurrentHashMap<XMPPConnection, ServiceDiscoveryManager>();
private XMPPConnection connection;
private final List<String> features = new ArrayList<String>();
private Map<String, NodeInformationProvider> nodeInformationProviders =
new ConcurrentHashMap<String, NodeInformationProvider>();
// Create a new ServiceDiscoveryManager on every established connection
static {
XMPPConnection.addConnectionListener(new ConnectionEstablishedListener() {
public void connectionEstablished(XMPPConnection connection) {
new ServiceDiscoveryManager(connection);
}
});
}
/**
* Creates a new ServiceDiscoveryManager for a given XMPPConnection. This means that the
* service manager will respond to any service discovery request that the connection may
* receive.
*
* @param connection the connection to which a ServiceDiscoveryManager is going to be created.
*/
public ServiceDiscoveryManager(XMPPConnection connection) {
this.connection = connection;
init();
}
/**
* Returns the ServiceDiscoveryManager instance associated with a given XMPPConnection.
*
* @param connection the connection used to look for the proper ServiceDiscoveryManager.
* @return the ServiceDiscoveryManager associated with a given XMPPConnection.
*/
public static ServiceDiscoveryManager getInstanceFor(XMPPConnection connection) {
return instances.get(connection);
}
/**
* Returns the name of the client that will be returned when asked for the client identity
* in a disco request. The name could be any value you need to identity this client.
*
* @return the name of the client that will be returned when asked for the client identity
* in a disco request.
*/
public static String getIdentityName() {
return identityName;
}
/**
* Sets the name of the client that will be returned when asked for the client identity
* in a disco request. The name could be any value you need to identity this client.
*
* @param name the name of the client that will be returned when asked for the client identity
* in a disco request.
*/
public static void setIdentityName(String name) {
identityName = name;
}
/**
* Returns the type of client that will be returned when asked for the client identity in a
* disco request. The valid types are defined by the category client. Follow this link to learn
* the possible types: <a href="http://www.jabber.org/registrar/disco-categories.html#client">Jabber::Registrar</a>.
*
* @return the type of client that will be returned when asked for the client identity in a
* disco request.
*/
public static String getIdentityType() {
return identityType;
}
/**
* Sets the type of client that will be returned when asked for the client identity in a
* disco request. The valid types are defined by the category client. Follow this link to learn
* the possible types: <a href="http://www.jabber.org/registrar/disco-categories.html#client">Jabber::Registrar</a>.
*
* @param type the type of client that will be returned when asked for the client identity in a
* disco request.
*/
public static void setIdentityType(String type) {
identityType = type;
}
/**
* Initializes the packet listeners of the connection that will answer to any
* service discovery request.
*/
private void init() {
// Register the new instance and associate it with the connection
instances.put(connection, this);
// Add a listener to the connection that removes the registered instance when
// the connection is closed
connection.addConnectionListener(new ConnectionListener() {
public void connectionClosed() {
// Unregister this instance since the connection has been closed
instances.remove(connection);
}
public void connectionClosedOnError(Exception e) {
// Unregister this instance since the connection has been closed
instances.remove(connection);
}
});
// Listen for disco#items requests and answer with an empty result
PacketFilter packetFilter = new PacketTypeFilter(DiscoverItems.class);
PacketListener packetListener = new PacketListener() {
public void processPacket(Packet packet) {
DiscoverItems discoverItems = (DiscoverItems) packet;
// Send back the items defined in the client if the request is of type GET
if (discoverItems != null && discoverItems.getType() == IQ.Type.GET) {
DiscoverItems response = new DiscoverItems();
response.setType(IQ.Type.RESULT);
response.setTo(discoverItems.getFrom());
response.setPacketID(discoverItems.getPacketID());
response.setNode(discoverItems.getNode());
// Add the defined items related to the requested node. Look for
// the NodeInformationProvider associated with the requested node.
NodeInformationProvider nodeInformationProvider =
getNodeInformationProvider(discoverItems.getNode());
if (nodeInformationProvider != null) {
// Specified node was found
Iterator items = nodeInformationProvider.getNodeItems();
if (items != null) {
while (items.hasNext()) {
response.addItem((DiscoverItems.Item) items.next());
}
}
} else if(discoverItems.getNode() != null) {
// Return <item-not-found/> error since client doesn't contain
// the specified node
response.setType(IQ.Type.ERROR);
response.setError(new XMPPError(XMPPError.Condition.item_not_found));
}
connection.sendPacket(response);
}
}
};
connection.addPacketListener(packetListener, packetFilter);
// Listen for disco#info requests and answer the client's supported features
// To add a new feature as supported use the #addFeature message
packetFilter = new PacketTypeFilter(DiscoverInfo.class);
packetListener = new PacketListener() {
public void processPacket(Packet packet) {
DiscoverInfo discoverInfo = (DiscoverInfo) packet;
// Answer the client's supported features if the request is of the GET type
if (discoverInfo != null && discoverInfo.getType() == IQ.Type.GET) {
DiscoverInfo response = new DiscoverInfo();
response.setType(IQ.Type.RESULT);
response.setTo(discoverInfo.getFrom());
response.setPacketID(discoverInfo.getPacketID());
response.setNode(discoverInfo.getNode());
// Add the client's identity and features only if "node" is null
if (discoverInfo.getNode() == null) {
// Set this client identity
DiscoverInfo.Identity identity = new DiscoverInfo.Identity("client",
getIdentityName());
identity.setType(getIdentityType());
response.addIdentity(identity);
// Add the registered features to the response
synchronized (features) {
for (Iterator<String> it = getFeatures(); it.hasNext();) {
response.addFeature(it.next());
}
}
}
else {
// Disco#info was sent to a node. Check if we have information of the
// specified node
NodeInformationProvider nodeInformationProvider =
getNodeInformationProvider(discoverInfo.getNode());
if (nodeInformationProvider != null) {
// Node was found. Add node features
Iterator features = nodeInformationProvider.getNodeFeatures();
if (features != null) {
while (features.hasNext()) {
response.addFeature((String) features.next());
}
}
}
else {
// Return <item-not-found/> error since specified node was not found
response.setType(IQ.Type.ERROR);
response.setError(new XMPPError(XMPPError.Condition.item_not_found));
}
}
connection.sendPacket(response);
}
}
};
connection.addPacketListener(packetListener, packetFilter);
}
/**
* Returns the NodeInformationProvider responsible for providing information
* (ie items) related to a given node or <tt>null</null> if none.<p>
*
* In MUC, a node could be 'http://jabber.org/protocol/muc#rooms' which means that the
* NodeInformationProvider will provide information about the rooms where the user has joined.
*
* @param node the node that contains items associated with an entity not addressable as a JID.
* @return the NodeInformationProvider responsible for providing information related
* to a given node.
*/
private NodeInformationProvider getNodeInformationProvider(String node) {
if (node == null) {
return null;
}
return nodeInformationProviders.get(node);
}
/**
* Sets the NodeInformationProvider responsible for providing information
* (ie items) related to a given node. Every time this client receives a disco request
* regarding the items of a given node, the provider associated to that node will be the
* responsible for providing the requested information.<p>
*
* In MUC, a node could be 'http://jabber.org/protocol/muc#rooms' which means that the
* NodeInformationProvider will provide information about the rooms where the user has joined.
*
* @param node the node whose items will be provided by the NodeInformationProvider.
* @param listener the NodeInformationProvider responsible for providing items related
* to the node.
*/
public void setNodeInformationProvider(String node, NodeInformationProvider listener) {
nodeInformationProviders.put(node, listener);
}
/**
* Removes the NodeInformationProvider responsible for providing information
* (ie items) related to a given node. This means that no more information will be
* available for the specified node.
*
* In MUC, a node could be 'http://jabber.org/protocol/muc#rooms' which means that the
* NodeInformationProvider will provide information about the rooms where the user has joined.
*
* @param node the node to remove the associated NodeInformationProvider.
*/
public void removeNodeInformationProvider(String node) {
nodeInformationProviders.remove(node);
}
/**
* Returns the supported features by this XMPP entity.
*
* @return an Iterator on the supported features by this XMPP entity.
*/
public Iterator<String> getFeatures() {
synchronized (features) {
return Collections.unmodifiableList(new ArrayList<String>(features)).iterator();
}
}
/**
* Registers that a new feature is supported by this XMPP entity. When this client is
* queried for its information the registered features will be answered.<p>
*
* Since no packet is actually sent to the server it is safe to perform this operation
* before logging to the server. In fact, you may want to configure the supported features
* before logging to the server so that the information is already available if it is required
* upon login.
*
* @param feature the feature to register as supported.
*/
public void addFeature(String feature) {
synchronized (features) {
features.add(feature);
}
}
/**
* Removes the specified feature from the supported features by this XMPP entity.<p>
*
* Since no packet is actually sent to the server it is safe to perform this operation
* before logging to the server.
*
* @param feature the feature to remove from the supported features.
*/
public void removeFeature(String feature) {
synchronized (features) {
features.remove(feature);
}
}
/**
* Returns true if the specified feature is registered in the ServiceDiscoveryManager.
*
* @param feature the feature to look for.
* @return a boolean indicating if the specified featured is registered or not.
*/
public boolean includesFeature(String feature) {
synchronized (features) {
return features.contains(feature);
}
}
/**
* Returns the discovered information of a given XMPP entity addressed by its JID.
*
* @param entityID the address of the XMPP entity.
* @return the discovered information.
* @throws XMPPException if the operation failed for some reason.
*/
public DiscoverInfo discoverInfo(String entityID) throws XMPPException {
return discoverInfo(entityID, null);
}
/**
* Returns the discovered information of a given XMPP entity addressed by its JID and
* note attribute. Use this message only when trying to query information which is not
* directly addressable.
*
* @param entityID the address of the XMPP entity.
* @param node the attribute that supplements the 'jid' attribute.
* @return the discovered information.
* @throws XMPPException if the operation failed for some reason.
*/
public DiscoverInfo discoverInfo(String entityID, String node) throws XMPPException {
// Discover the entity's info
DiscoverInfo disco = new DiscoverInfo();
disco.setType(IQ.Type.GET);
disco.setTo(entityID);
disco.setNode(node);
// Create a packet collector to listen for a response.
PacketCollector collector =
connection.createPacketCollector(new PacketIDFilter(disco.getPacketID()));
connection.sendPacket(disco);
// Wait up to 5 seconds for a result.
IQ result = (IQ) collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
// Stop queuing results
collector.cancel();
if (result == null) {
throw new XMPPException("No response from the server.");
}
if (result.getType() == IQ.Type.ERROR) {
throw new XMPPException(result.getError());
}
return (DiscoverInfo) result;
}
/**
* Returns the discovered items of a given XMPP entity addressed by its JID.
*
* @param entityID the address of the XMPP entity.
* @return the discovered information.
* @throws XMPPException if the operation failed for some reason.
*/
public DiscoverItems discoverItems(String entityID) throws XMPPException {
return discoverItems(entityID, null);
}
/**
* Returns the discovered items of a given XMPP entity addressed by its JID and
* note attribute. Use this message only when trying to query information which is not
* directly addressable.
*
* @param entityID the address of the XMPP entity.
* @param node the attribute that supplements the 'jid' attribute.
* @return the discovered items.
* @throws XMPPException if the operation failed for some reason.
*/
public DiscoverItems discoverItems(String entityID, String node) throws XMPPException {
// Discover the entity's items
DiscoverItems disco = new DiscoverItems();
disco.setType(IQ.Type.GET);
disco.setTo(entityID);
disco.setNode(node);
// Create a packet collector to listen for a response.
PacketCollector collector =
connection.createPacketCollector(new PacketIDFilter(disco.getPacketID()));
connection.sendPacket(disco);
// Wait up to 5 seconds for a result.
IQ result = (IQ) collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
// Stop queuing results
collector.cancel();
if (result == null) {
throw new XMPPException("No response from the server.");
}
if (result.getType() == IQ.Type.ERROR) {
throw new XMPPException(result.getError());
}
return (DiscoverItems) result;
}
/**
* Returns true if the server supports publishing of items. A client may wish to publish items
* to the server so that the server can provide items associated to the client. These items will
* be returned by the server whenever the server receives a disco request targeted to the bare
* address of the client (i.e. user@host.com).
*
* @param entityID the address of the XMPP entity.
* @return true if the server supports publishing of items.
* @throws XMPPException if the operation failed for some reason.
*/
public boolean canPublishItems(String entityID) throws XMPPException {
DiscoverInfo info = discoverInfo(entityID);
return info.containsFeature("http://jabber.org/protocol/disco#publish");
}
/**
* Publishes new items to a parent entity. The item elements to publish MUST have at least
* a 'jid' attribute specifying the Entity ID of the item, and an action attribute which
* specifies the action being taken for that item. Possible action values are: "update" and
* "remove".
*
* @param entityID the address of the XMPP entity.
* @param discoverItems the DiscoveryItems to publish.
* @throws XMPPException if the operation failed for some reason.
*/
public void publishItems(String entityID, DiscoverItems discoverItems)
throws XMPPException {
publishItems(entityID, null, discoverItems);
}
/**
* Publishes new items to a parent entity and node. The item elements to publish MUST have at
* least a 'jid' attribute specifying the Entity ID of the item, and an action attribute which
* specifies the action being taken for that item. Possible action values are: "update" and
* "remove".
*
* @param entityID the address of the XMPP entity.
* @param node the attribute that supplements the 'jid' attribute.
* @param discoverItems the DiscoveryItems to publish.
* @throws XMPPException if the operation failed for some reason.
*/
public void publishItems(String entityID, String node, DiscoverItems discoverItems)
throws XMPPException {
discoverItems.setType(IQ.Type.SET);
discoverItems.setTo(entityID);
discoverItems.setNode(node);
// Create a packet collector to listen for a response.
PacketCollector collector =
connection.createPacketCollector(new PacketIDFilter(discoverItems.getPacketID()));
connection.sendPacket(discoverItems);
// Wait up to 5 seconds for a result.
IQ result = (IQ) collector.nextResult(SmackConfiguration.getPacketReplyTimeout());
// Stop queuing results
collector.cancel();
if (result == null) {
throw new XMPPException("No response from the server.");
}
if (result.getType() == IQ.Type.ERROR) {
throw new XMPPException(result.getError());
}
}
}