pubsubengine.java

基于Jabber协议的即时消息服务器

            if (!service.isInstantNodeSupported()) {
                // Instant nodes creation is not allowed so return an error
                Element pubsubError = DocumentHelper.createElement(
                        QName.get("nodeid-required", "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.not_acceptable, pubsubError);
                return;
            }
            do {
                // Create a new nodeID and make sure that the random generated string does not
                // match an existing node. Probability to match an existing node are very very low
                // but they exist :)
                newNodeID = StringUtils.randomString(15);
            }
            while (service.getNode(newNodeID) != null);
        }
        // Check if user requested to configure the node (using a data form)
        Element configureElement = childElement.element("configure");
        if (configureElement != null) {
            // Get the data form that contains the parent nodeID
            completedForm = getSentConfigurationForm(configureElement);
            if (completedForm != null) {
                // Calculate newNodeID when new node is affiliated with a Collection
                FormField field = completedForm.getField("pubsub#collection");
                if (field != null) {
                    List<String> values = field.getValues();
                    if (!values.isEmpty()) {
                        String parentNodeID = values.get(0);
                        Node tempNode = service.getNode(parentNodeID);
                        if (tempNode == null) {
                            // Requested parent node was not found so return an error
                            sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
                            return;
                        }
                        else if (!tempNode.isCollectionNode()) {
                            // Requested parent node is not a collection node so return an error
                            sendErrorPacket(iq, PacketError.Condition.not_acceptable, null);
                            return;
                        }
                        parentNode = (CollectionNode) tempNode;
                        // If requested new nodeID does not contain parent nodeID then add
                        // the parent nodeID to the beginging of the new nodeID
                        if (!newNodeID.startsWith(parentNodeID)) {
                            newNodeID = parentNodeID + "/" + newNodeID;
                        }
                    }
                }
            }
        }
        // If no parent was defined then use the root collection node
        if (parentNode == null && service.isCollectionNodesSupported()) {
            parentNode = service.getRootCollectionNode();
            // Calculate new nodeID for the new node
            if (!newNodeID.startsWith(parentNode.getNodeID() + "/")) {
                newNodeID = parentNode.getNodeID() + "/" + newNodeID;
            }
        }
        // Check that the requested nodeID does not exist
        Node existingNode = service.getNode(newNodeID);
        if (existingNode != null) {
            // There is a conflict since a node with the same ID already exists
            sendErrorPacket(iq, PacketError.Condition.conflict, null);
            return;
        }

        // Check if user requested to create a new collection node
        boolean collectionType = "collection".equals(createElement.attributeValue("type"));

        if (collectionType && !service.isCollectionNodesSupported()) {
            // Cannot create a collection node since the service doesn't support it
            Element pubsubError = DocumentHelper.createElement(
                    QName.get("unsupported", "http://jabber.org/protocol/pubsub#errors"));
            pubsubError.addAttribute("feature", "collections");
            sendErrorPacket(iq, PacketError.Condition.feature_not_implemented, pubsubError);
            return;
        }

        if (parentNode != null && !collectionType) {
            // Check if requester is allowed to add a new leaf child node to the parent node
            if (!parentNode.isAssociationAllowed(from)) {
                // User is not allowed to add child leaf node to parent node. Return an error.
                sendErrorPacket(iq, PacketError.Condition.forbidden, null);
                return;
            }
            // Check if number of child leaf nodes has not been exceeded
            if (parentNode.isMaxLeafNodeReached()) {
                // Max number of child leaf nodes has been reached. Return an error.
                Element pubsubError = DocumentHelper.createElement(QName.get("max-nodes-exceeded",
                        "http://jabber.org/protocol/pubsub#errors"));
                sendErrorPacket(iq, PacketError.Condition.conflict, pubsubError);
                return;
            }
        }

        // Create and configure the node
        boolean conflict = false;
        Node newNode = null;
        try {
            // TODO Assumed that the owner of the subscription is the bare JID of the subscription JID. Waiting StPeter answer for explicit field.
            JID owner = new JID(from.toBareJID());
            synchronized (newNodeID.intern()) {
                if (service.getNode(newNodeID) == null) {
                    // Create the node
                    if (collectionType) {
                        newNode = new CollectionNode(service, parentNode, newNodeID, from);
                    }
                    else {
                        newNode = new LeafNode(service, parentNode, newNodeID, from);
                    }
                    // Add the creator as the node owner
                    newNode.addOwner(owner);
                    // Configure and save the node to the backend store
                    if (completedForm != null) {
                        newNode.configure(completedForm);
                    }
                    else {
                        newNode.saveToDB();
                    }
                }
                else {
                    conflict = true;
                }
            }
            if (conflict) {
                // There is a conflict since a node with the same ID already exists
                sendErrorPacket(iq, PacketError.Condition.conflict, null);
            }
            else {
                // Return success to the node owner
                IQ reply = IQ.createResultIQ(iq);
                // Include new nodeID if it has changed from the original nodeID
                if (!newNode.getNodeID().equals(nodeID)) {
                    Element elem =
                            reply.setChildElement("pubsub", "http://jabber.org/protocol/pubsub");
                    elem.addElement("create").addAttribute("node", newNode.getNodeID());
                }
                router.route(reply);
            }
        }
        catch (NotAcceptableException e) {
            // Node should have at least one owner. Return not-acceptable error.
            sendErrorPacket(iq, PacketError.Condition.not_acceptable, null);
        }
    }

    private void getNodeConfiguration(IQ iq, Element childElement, String nodeID) {
        Node node = service.getNode(nodeID);
        if (node == null) {
            // Node does not exist. Return item-not-found error
            sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
            return;
        }
        if (!node.isAdmin(iq.getFrom())) {
            // Requesting entity is prohibited from configuring this node. Return forbidden error
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }

        // Return data form containing node configuration to the owner
        IQ reply = IQ.createResultIQ(iq);
        Element replyChildElement = childElement.createCopy();
        reply.setChildElement(replyChildElement);
        replyChildElement.element("configure").add(node.getConfigurationForm().getElement());
        router.route(reply);
    }

    private void getDefaultNodeConfiguration(IQ iq, Element childElement, Element defaultElement) {
        String type = defaultElement.attributeValue("type");
        type = type == null ? "leaf" : type;

        boolean isLeafType = "leaf".equals(type);
        DefaultNodeConfiguration config = service.getDefaultNodeConfiguration(isLeafType);
        if (config == null) {
            // Service does not support the requested node type so return an error
            Element pubsubError = DocumentHelper.createElement(
                    QName.get("unsupported", "http://jabber.org/protocol/pubsub#errors"));
            pubsubError.addAttribute("feature", isLeafType ? "leaf" : "collections");
            sendErrorPacket(iq, PacketError.Condition.feature_not_implemented, pubsubError);
            return;
        }

        // Return data form containing default node configuration
        IQ reply = IQ.createResultIQ(iq);
        Element replyChildElement = childElement.createCopy();
        reply.setChildElement(replyChildElement);
        replyChildElement.element("default").add(config.getConfigurationForm().getElement());
        router.route(reply);
    }

    private void configureNode(IQ iq, Element configureElement, String nodeID) {
        Node node = service.getNode(nodeID);
        if (node == null) {
            // Node does not exist. Return item-not-found error
            sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
            return;
        }
        if (!node.isAdmin(iq.getFrom())) {
            // Requesting entity is not allowed to get node configuration. Return forbidden error
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }

        // Get the data form that contains the parent nodeID
        DataForm completedForm = getSentConfigurationForm(configureElement);
        if (completedForm != null) {
            try {
                // Update node configuration with the provided data form
                // (and update the backend store)
                node.configure(completedForm);
                // Return that node configuration was successful
                router.route(IQ.createResultIQ(iq));
            }
            catch (NotAcceptableException e) {
                // Node should have at least one owner. Return not-acceptable error.
                sendErrorPacket(iq, PacketError.Condition.not_acceptable, null);
            }
        }
        else {
            // No data form was included so return bad-request error
            sendErrorPacket(iq, PacketError.Condition.bad_request, null);
        }
    }

    private void deleteNode(IQ iq, Element deleteElement) {
        String nodeID = deleteElement.attributeValue("node");
        if (nodeID == null) {
            // NodeID was not provided. Return bad-request error
            sendErrorPacket(iq, PacketError.Condition.bad_request, null);
            return;
        }
        Node node = service.getNode(nodeID);
        if (node == null) {
            // Node does not exist. Return item-not-found error
            sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
            return;
        }
        if (!node.isAdmin(iq.getFrom())) {
            // Requesting entity is prohibited from deleting this node. Return forbidden error
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }
        if (node.isRootCollectionNode()) {
            // Root collection node cannot be deleted. Return not-allowed error
            sendErrorPacket(iq, PacketError.Condition.not_allowed, null);
            return;
        }

        // Delete the node
        if (node.delete()) {
            // Return that node was deleted successfully
            router.route(IQ.createResultIQ(iq));
        }
        else {
            // Some error occured while trying to delete the node
            sendErrorPacket(iq, PacketError.Condition.internal_server_error, null);
        }
    }

    private void purgeNode(IQ iq, Element purgeElement) {
        String nodeID = purgeElement.attributeValue("node");
        if (nodeID == null) {
            // NodeID was not provided. Return bad-request error
            sendErrorPacket(iq, PacketError.Condition.bad_request, null);
            return;
        }
        Node node = service.getNode(nodeID);
        if (node == null) {
            // Node does not exist. Return item-not-found error
            sendErrorPacket(iq, PacketError.Condition.item_not_found, null);
            return;
        }
        if (!node.isAdmin(iq.getFrom())) {
            // Requesting entity is prohibited from configuring this node. Return forbidden error
            sendErrorPacket(iq, PacketError.Condition.forbidden, null);
            return;
        }
        if (!((LeafNode) node).isPersistPublishedItems()) {
            // Node does not persist items. Return feature-not-implemented error
            Ele