org.apache.jackrabbit.webdav.observation.EventDiscovery Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.jackrabbit.webdav.observation;
import org.apache.jackrabbit.webdav.xml.DomUtil;
import org.apache.jackrabbit.webdav.xml.ElementIterator;
import org.apache.jackrabbit.webdav.xml.XmlSerializable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* EventDiscovery represents the request body of a successful
* POLL request. It reveals all events that occurred since the last POLL. The
* definition what events that particular subscription is interested in was
* specified with the initial SUBSCRIPTION that started the event listening.
*/
public class EventDiscovery implements ObservationConstants, XmlSerializable {
private static Logger log = LoggerFactory.getLogger(EventDiscovery.class);
private final List bundles = new ArrayList();
/**
* Add the Xml representation of an single 'eventBundle' listing the
* events that resulted from a change in the server, filtered by the
* restrictions present in the corresponding subscription.
*
* @param eventBundle
* @see Subscription
*/
public void addEventBundle(EventBundle eventBundle) {
if (eventBundle != null) {
bundles.add(eventBundle);
}
}
/**
* Returns an iterator over the {@link EventBundle event bundles} currently
* present on this discovery.
*
* @return iterator over event bundles present.
*/
public Iterator getEventBundles() {
return bundles.iterator();
}
/**
* Returns true, if this event discovery does not report any events (thus
* {@link #getEventBundles()} would return an empty iterator.
*
* @return true if {@link #getEventBundles()} would return an empty iterator,
* false otherwise.
*/
public boolean isEmpty() {
return bundles.isEmpty();
}
/**
* Returns the Xml representation of this EventDiscovery as
* being present in the POLL response body.
*
* @return Xml representation
* @see org.apache.jackrabbit.webdav.xml.XmlSerializable#toXml(Document)
* @param document
*/
public Element toXml(Document document) {
Element ed = DomUtil.createElement(document, XML_EVENTDISCOVERY, NAMESPACE);
for (EventBundle bundle : bundles) {
ed.appendChild(bundle.toXml(document));
}
return ed;
}
/**
* Build a EventDiscovery from the specified xml element.
*
* @param eventDiscoveryElement
* @return new EventDiscovery instance.
* @throws IllegalArgumentException if the given document is null
* or does not provide the required element.
*/
public static EventDiscovery createFromXml(Element eventDiscoveryElement) {
if (!DomUtil.matches(eventDiscoveryElement, XML_EVENTDISCOVERY, ObservationConstants.NAMESPACE)) {
throw new IllegalArgumentException(
"{" + ObservationConstants.NAMESPACE + "}" + XML_EVENTDISCOVERY + " element expected, but got: {"
+ eventDiscoveryElement.getNamespaceURI() + "}" + eventDiscoveryElement.getLocalName());
}
EventDiscovery eventDiscovery = new EventDiscovery();
ElementIterator it = DomUtil.getChildren(eventDiscoveryElement, XML_EVENTBUNDLE, ObservationConstants.NAMESPACE);
while (it.hasNext()) {
final Element ebElement = it.nextElement();
EventBundle eb = new EventBundle() {
public Element toXml(Document document) {
return (Element) document.importNode(ebElement, true);
}
};
eventDiscovery.addEventBundle(eb);
}
return eventDiscovery;
}
}