org.apache.jackrabbit.webdav.client.methods.PollMethod.java Source code

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Here is the source code for org.apache.jackrabbit.webdav.client.methods.PollMethod.java

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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  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.client.methods;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.jackrabbit.webdav.DavMethods;
import org.apache.jackrabbit.webdav.DavServletResponse;
import org.apache.jackrabbit.webdav.DavException;
import org.apache.jackrabbit.webdav.header.PollTimeoutHeader;
import org.apache.jackrabbit.webdav.xml.DomUtil;
import org.apache.jackrabbit.webdav.xml.ElementIterator;
import org.apache.jackrabbit.webdav.observation.ObservationConstants;
import org.apache.jackrabbit.webdav.observation.EventDiscovery;
import org.apache.jackrabbit.webdav.observation.EventBundle;
import org.apache.commons.httpclient.HttpMethodBase;
import org.apache.commons.httpclient.HttpState;
import org.apache.commons.httpclient.HttpConnection;
import org.w3c.dom.Element;
import org.w3c.dom.Document;

import java.io.IOException;

/**
 * <code>PollMethod</code> implementation.
 */
public class PollMethod extends DavMethodBase implements ObservationConstants {

    private static Logger log = LoggerFactory.getLogger(PollMethod.class);

    private EventDiscovery eventDiscovery;

    public PollMethod(String uri, String subscriptionId) {
        this(uri, subscriptionId, 0);
    }

    public PollMethod(String uri, String subscriptionId, long timeout) {
        super(uri);
        setRequestHeader(ObservationConstants.HEADER_SUBSCRIPTIONID, subscriptionId);
        if (timeout > 0) {
            setRequestHeader(new PollTimeoutHeader(timeout));
        }
    }

    public EventDiscovery getResponseAsEventDiscovery() throws IOException, DavException {
        checkUsed();
        if (eventDiscovery != null) {
            return eventDiscovery;
        } else {
            DavException dx = getResponseException();
            if (dx != null) {
                throw dx;
            } else {
                throw new DavException(getStatusCode(),
                        getName() + " resulted with unexpected status: " + getStatusLine());
            }
        }
    }

    //---------------------------------------------------------< HttpMethod >---
    @Override
    public String getName() {
        return DavMethods.METHOD_POLL;
    }

    //------------------------------------------------------< DavMethodBase >---
    @Override
    protected boolean isSuccess(int statusCode) {
        return DavServletResponse.SC_OK == statusCode;
    }

    //------------------------------------------------------< HttpMethodBase >---
    /**
     * Retrieves the DAV:subscriptiondiscovery property present in the response body
     * and builds 'Subscription' objects from the corresponding DAV:subscription
     * child elements inside the discovery. If parsing the response body
     * fails for whatever reason or if the DAV:subscriptiondiscovery did not contain
     * at least a single DAV:subscription entry (the one created by the SUBSCRIBE
     * call) this methods in addition resets the 'success' flag to false.
     *
     * @param httpState
     * @param httpConnection
     * @see HttpMethodBase#processResponseBody(HttpState, HttpConnection)
     */
    @Override
    protected void processResponseBody(HttpState httpState, HttpConnection httpConnection) {
        // in case of successful response code -> parse xml body discovery object
        if (getSuccess()) {
            try {
                setSuccess(buildDiscoveryFromRoot(getRootElement()));
            } catch (IOException e) {
                log.error("Error while parsing multistatus response: " + e);
                setSuccess(false);
            }
        }
    }

    //------------------------------------------------------------< private >---
    /**
     *
     * @param root
     * @return
     */
    private boolean buildDiscoveryFromRoot(Element root) {
        if (DomUtil.matches(root, XML_EVENTDISCOVERY, ObservationConstants.NAMESPACE)) {
            eventDiscovery = new EventDiscovery();
            ElementIterator it = DomUtil.getChildren(root, 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 true;
        } else {
            log.debug("Missing 'eventdiscovery' response body in POLL method.");
        }
        return false;
    }
}