rendezvouspropagatemessage.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  
 *  2. Redistributions in binary form must reproduce the above copyright notice, 
 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
 *  
 *  3. The end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
 *  
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
 *     without prior written permission. For written permission, please contact 
 *     Project JXTA at http://www.jxta.org.
 *  
 *  5. Products derived from this software may not be called "JXTA", nor may 
 *     "JXTA" appear in their name, without prior written permission of Sun.
 *  
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 *  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
 *  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN 
 *  MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 *  OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
 *  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */
package net.jxta.impl.rendezvous;

import net.jxta.document.Attributable;
import net.jxta.document.Attribute;
import net.jxta.document.Document;
import net.jxta.document.Element;
import net.jxta.document.MimeMediaType;
import net.jxta.document.StructuredDocument;
import net.jxta.document.StructuredDocumentFactory;
import net.jxta.document.XMLDocument;
import net.jxta.document.XMLElement;
import net.jxta.impl.id.UUID.UUID;
import net.jxta.impl.id.UUID.UUIDFactory;
import net.jxta.logging.Logging;

import java.net.URI;
import java.util.Enumeration;
import java.util.LinkedHashSet;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * This class defines the wire format of the Propagation header for messages.
 */
public class RendezVousPropagateMessage {

    /**
     * Logger
     */
    private final static transient Logger LOG = Logger.getLogger(RendezVousPropagateMessage.class.getName());

    public final static String MSG_NAME = "jxta:RendezVousPropagateMessage";
    public static final String MsgIdTag = "MessageId";
    public final static String DestSNameTag = "DestSName";
    public final static String DestSParamTag = "DestSParam";
    public final static String TTLTag = "TTL";
    public final static String PathTag = "Path";

    /**
     * Description of the Field
     */
    public final static String Name = "RendezVousPropagate";

    private UUID msgId = null;
    private String destSName = null;
    private String destSParam = null;
    private int TTL = Integer.MIN_VALUE;
    private final Set<URI> visited = new LinkedHashSet<URI>();

    /**
     * Constructor for the RendezVousPropagateMessage object
     */
    public RendezVousPropagateMessage() {}

    /**
     * Constructor for the RendezVousPropagateMessage object
     *
     * @param root The root element of the message.
     */
    public RendezVousPropagateMessage(Element root) {
        this();

        if (!XMLElement.class.isInstance(root)) {
            throw new IllegalArgumentException(getClass().getName() + " only supports XLMElement");
        }

        XMLElement doc = (XMLElement) root;

        String doctype = doc.getName();

        String typedoctype = "";
        Attribute itsType = doc.getAttribute("type");

        if (null != itsType) {
            typedoctype = itsType.getValue();
        }

        if (!doctype.equals(MSG_NAME) && !MSG_NAME.equals(typedoctype)) {
            throw new IllegalArgumentException(
                    "Could not construct : " + getClass().getName() + "from doc containing a " + doc.getName());
        }

        Enumeration elements = doc.getChildren();

        while (elements.hasMoreElements()) {
            XMLElement elem = (XMLElement) elements.nextElement();

            if (!handleElement(elem)) {
                if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                    LOG.fine("Unhandled Element: " + elem.toString());
                }
            }
        }

        // Sanity Check!!!

        if (Integer.MIN_VALUE == getTTL()) {
            throw new IllegalArgumentException("TTL value not specified");
        }

        if (null == destSName) {
            throw new IllegalArgumentException("Destination service name uninitialized");
        }

        if (null == msgId) {
            throw new IllegalArgumentException("Message id uninitialized");
        }
    }

    /**
     * Process the document
     *
     * @param raw the document
     * @return true if successful
     */
    protected boolean handleElement(Element raw) {

        XMLElement elem = (XMLElement) raw;

        if (elem.getName().equals(MsgIdTag)) {
            try {
                msgId = new UUID(elem.getTextValue().trim());
            } catch (IllegalArgumentException iae) {
                // old message id format
                try {
                    msgId = UUIDFactory.newHashUUID(Long.parseLong(elem.getTextValue().trim()), 0);
                } catch (NumberFormatException notanumber) {
                    msgId = UUIDFactory.newHashUUID(elem.getTextValue().trim().hashCode(), 0);
                }
            }
            return true;
        }

        if (elem.getName().equals(DestSNameTag)) {
            destSName = elem.getTextValue().trim();
            return true;
        }

        if (elem.getName().equals(DestSParamTag)) {
            destSParam = elem.getTextValue().trim();
            return true;
        }

        if (elem.getName().equals(TTLTag)) {
            TTL = Integer.parseInt(elem.getTextValue().trim());
            return true;
        }

        if (elem.getName().equals(PathTag)) {
            addVisited(URI.create(elem.getTextValue().trim()));
            return true;
        }

        return false;
    }

    public UUID getMsgId() {
        return msgId;
    }

    public void setMsgId(UUID id) {
        msgId = id;
    }

    public String getDestSName() {
        return destSName;
    }

    public void setDestSName(String sName) {
        this.destSName = sName;
    }

    public String getDestSParam() {
        return destSParam;
    }

    public void setDestSParam(String sParam) {
        this.destSParam = sParam;
    }

    /**
     * Gets the TTL attribute of the RendezVousPropagateMessage object
     *
     * @return The TTL value
     */
    public int getTTL() {
        return TTL;
    }

    /**
     * Sets the TTL attribute of the RendezVousPropagateMessage object
     *
     * @param ttl The new TTL value
     */
    public void setTTL(int ttl) {
        TTL = ttl;
    }

    /**
     * Adds a location to the Visited Set
     *
     * @param location which was visited.
     */
    public void addVisited(URI location) {
        visited.add(location);
    }

    /**
     * Returns true if the specified location is in the visited Set.
     *
     * @param location The location to check
     * @return true if specified location has been visited.
     */
    public boolean isVisited(URI location) {
        return visited.contains(location);
    }

    /**
     * Returns the path which this message has travelled.
     *
     * @return the path this message travelled.
     */
    public URI[] getPath() {
        return visited.toArray(new URI[visited.size()]);
    }

    public Document getDocument(MimeMediaType encodeAs) {

        // Sanity Check!!!

        if (getTTL() <= 0) {
            throw new IllegalStateException("TTL value < 1");
        }

        if (null == destSName) {
            throw new IllegalStateException("Destination service name uninitialized");
        }

        if (null == msgId) {
            throw new IllegalStateException("Message id uninitialized");
        }

        if (visited.isEmpty()) {
            throw new IllegalStateException("Message has not visited local peer.");
        }

        StructuredDocument doc = StructuredDocumentFactory.newStructuredDocument(encodeAs, MSG_NAME);

        if (doc instanceof XMLDocument) {
            ((Attributable) doc).addAttribute("xmlns:jxta", "http://jxta.org");
            ((Attributable) doc).addAttribute("xml:space", "preserve");
        }

        Element e = null;

        e = doc.createElement(MsgIdTag, msgId.toString());
        doc.appendChild(e);

        e = doc.createElement(DestSNameTag, destSName);
        doc.appendChild(e);

        if (null != destSParam) {
            e = doc.createElement(DestSParamTag, destSParam);
            doc.appendChild(e);
        }

        e = doc.createElement(TTLTag, Integer.toString(TTL));
        doc.appendChild(e);

        for (Object aVisited : visited) {
            e = doc.createElement(PathTag, aVisited.toString());
            doc.appendChild(e);
        }
        return doc;
    }
}