discoveryresponse.java

jxta_src_2.41b jxta 2.41b 最新版源码 from www.jxta.org

/*
 *  Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 *  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 the
 *  Sun Microsystems, Inc. for Project JXTA."
 *  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.
 *  ====================================================================
 *
 *  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.
 *
 *  $Id: DiscoveryResponse.java,v 1.47 2005/04/15 20:39:18 hamada Exp $
 */
package net.jxta.impl.protocol;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.UndeclaredThrowableException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
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.StructuredDocumentFactory;
import net.jxta.document.StructuredTextDocument;
import net.jxta.document.TextElement;
import net.jxta.document.XMLDocument;
import net.jxta.protocol.DiscoveryResponseMsg;
import net.jxta.protocol.PeerAdvertisement;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;

/**
 *  DiscoveryResponse.
 *
 *  <p/>This message is part of the standard JXTA Peer Discovery Protocol (PDP).
 *
 *  <pre>
 * &lt;xs:element name="DiscoveryResponse" type="jxta:DiscoveryResponse"/>
 *
 * &lt;xs:complexType name="DiscoveryResponse">
 *   &lt;xs:sequence>
 *     &lt;xs:element name="Type" type="jxta:DiscoveryQueryType"/>
 *     &lt;xs:element name="Count" type="xs:unsignedInt" minOccurs="0"/>
 *     &lt;xs:element name="Attr" type="xs:string" minOccurs="0"/>
 *     &lt;xs:element name="Value" type="xs:string" minOccurs="0"/>
 *     &lt;!-- The following should refer to a peer adv, but is instead a whole doc for historical reasons -->
 *     &lt;xs:element name="PeerAdv" minOccurs="0">
 *     &lt;xs:complexType>
 *       &lt;xs:simpleContent>
 *         &lt;xs:extension base="xs:string">
 *           &lt;xs:attribute name="Expiration" type="xs:unsignedLong"/>
 *         &lt;/xs:extension>
 *       &lt;/xs:simpleContent>
 *     &lt;/xs:complexType>
 *     &lt;/xs:element>
 *     &lt;xs:element name="Response" maxOccurs="unbounded">
 *     &lt;xs:complexType>
 *       &lt;xs:simpleContent>
 *         &lt;xs:extension base="xs:string">
 *           &lt;xs:attribute name="Expiration" type="xs:unsignedLong"/>
 *         &lt;/xs:extension>
 *       &lt;/xs:simpleContent>
 *     &lt;/xs:complexType>
 *     &lt;/xs:element>
 *   &lt;/xs:sequence>
 * &lt;/xs:complexType>
 * </pre>
 *
 *@see    net.jxta.discovery.DiscoveryService
 *@see    net.jxta.impl.discovery.DiscoveryServiceImpl
 *@see    <a href="http://spec.jxta.org/nonav/v1.0/docbook/JXTAProtocols.html#proto-pdp" 
 *        target="_blank">JXTA Protocols Specification : Peer Discovery Protocol</a>
 */
public class DiscoveryResponse extends DiscoveryResponseMsg {

    private final static transient Logger LOG = Logger.getLogger(DiscoveryResponse.class.getName());

    private final static String countTag = "Count";
    private final static String expirationTag = "Expiration";
    private final static String peerAdvTag = "PeerAdv";
    private final static String queryAttrTag = "Attr";
    private final static String queryValueTag = "Value";
    private final static String responsesTag = "Response";
    private final static String typeTag = "Type";

    /**
     *  Constructor for new instances.
     */
    public DiscoveryResponse() {
        super();
    }

    /**
     *  Construct from a StructuredDocument
     *
     *@param  root  Description of the Parameter
     */
    public DiscoveryResponse(Element root) {

        if (!TextElement.class.isInstance(root)) {
            throw new IllegalArgumentException(getClass().getName() + " only supports TextElement");
        }
        TextElement doc = (TextElement) root;
        String docName = doc.getName();
        if (!getAdvertisementType().equals(docName)) {
            throw new IllegalArgumentException("Could not construct : " +
                                               getClass().getName() + " from doc containing a " +
                                               docName);
        }
        readIt(doc);
    }


    /**
     * {@inheritDoc}
     */
    public Enumeration getAdvertisements() {
        if (null == advertisements) {
            parseAdvertisements();
        }

        if ((0 == advertisements.size()) && (getPeerAdvertisement() != null) && (type == DiscoveryService.PEER)) {
            // this takes care of the case where the only response
            // is the peerAdv
            advertisements = Collections.singletonList(peerAdvertisement);
        }
        return Collections.enumeration(advertisements);
    }

    /**
     *  set the responses to the query
     *
     *@param  advs  the responses for this query
     */
    protected void setAdvertisements(List advs) {
        this.advertisements = new ArrayList(advs);
    }

    /**
     * {@inheritDoc}
     */
    public Document getDocument(MimeMediaType asMimeType) {

        StructuredTextDocument adv = (StructuredTextDocument)
                                     StructuredDocumentFactory.newStructuredDocument(asMimeType,
                                             getAdvertisementType());

        if (adv instanceof XMLDocument) {
            ((XMLDocument) adv).addAttribute("xmlns:jxta", "http://jxta.org");
        }

        Enumeration advs = getResponses();
        Enumeration exps = getExpirations();

        Element e;
        e = adv.createElement(countTag, Integer.toString(responses.size()));
        adv.appendChild(e);
        e = adv.createElement(typeTag, Integer.toString(type));
        adv.appendChild(e);

        PeerAdvertisement myPeerAdv = getPeerAdvertisement();

        if(null != myPeerAdv) {
            e = adv.createElement(peerAdvTag, myPeerAdv.toString());
            adv.appendChild(e);
        }

        if ((attr != null) && (attr.length() > 0)) {
            e = adv.createElement(queryAttrTag, getQueryAttr());
            adv.appendChild(e);
            if ((value != null) && (value.length() > 0)) {
                e = adv.createElement(queryValueTag, value);
                adv.appendChild(e);