lightweightpeergroup.java

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

/*
 * Copyright (c) 2003 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: LightWeightPeerGroup.java,v 1.7 2006/02/22 01:29:43 bondolo Exp $
 */

package net.jxta.peergroup;

import java.net.URI;
import java.io.IOException;
import java.util.Iterator;
import java.util.Collections;

import net.jxta.access.AccessService;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.Element;
import net.jxta.endpoint.EndpointService;
import net.jxta.exception.ServiceNotFoundException;
import net.jxta.exception.PeerGroupException;
import net.jxta.exception.ProtocolNotSupportedException;
import net.jxta.id.ID;
import net.jxta.membership.MembershipService;
import net.jxta.peer.PeerID;
import net.jxta.peer.PeerInfoService;
import net.jxta.pipe.PipeService;
import net.jxta.platform.JxtaLoader;
import net.jxta.platform.Module;
import net.jxta.platform.ModuleSpecID;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PeerGroupAdvertisement;
import net.jxta.protocol.ModuleImplAdvertisement;
import net.jxta.protocol.ConfigParams;
import net.jxta.rendezvous.RendezVousService;
import net.jxta.resolver.ResolverService;
import net.jxta.service.Service;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

/**
 * LightWeightPeerGroup is a class intended to help
 * building PeerGroup that can inherit one or more
 * services from a parent PeerGroup.
 *
 * An LightWeightPeerGroup implements PeerGroup and is to
 * be used like a PeerGroup by applications.
 *
 * This class is intended to be extended/implemented.
 *
 * Note: unlike implementations of peer groups that existed until JXTA 2.2, 
 * LightweightPeergroup permits to implement groups that borrow all or 
 * part of their services to a parent group. One needs to remember 
 * that peers in various such subgroups of a given parent groups may 
 * implicitly all share the same services if that is what the PeerGroup
 * implementing LightWeightPeerGroup is doing. Please refer to the documentation
 * of PeerGroups extending LightWeigthPeerGroup do understand which
 * services are shared, and which are not.
 *
 **/

public class LightWeightPeerGroup implements PeerGroup {

    /**
     *  Log4J Logger
     **/
	private static final Logger LOG = Logger.getLogger(LightWeightPeerGroup.class.getName());

    private PeerGroup group = null;
    private ID assignedID  = null;
    private Advertisement implAdv = null;
    private final PeerGroupAdvertisement adv;

    /**
     * Constructor
     *
     * All classes that extend this class must invoke this
     * constructor.
     *
     * @param adv PeerGroupAdvertisement of this LightWeightPeerGroup.
     * Note that only the PeerGroupID is used.
     **/
    public LightWeightPeerGroup (PeerGroupAdvertisement adv) {
        this.adv = adv;
    }

    /***********************************************************
     ** Module API
     ***********************************************************/
    /**
    *	{@inheritDoc}
    **/
    public void init(PeerGroup group, ID assignedID, Advertisement implAdv) {
        this.group = group;
        this.assignedID = assignedID;
        this.implAdv = implAdv;
    }


    /**
    *	{@inheritDoc}
    **/
    public int startApp(String[] args) {
        if( null == group ) {
            if ( LOG.isEnabledFor(Level.ERROR) ) {
                LOG.error("No base peer group defined.");
            }
            return -1;
        }
        
        return START_OK;
    }

    /**
    *	{@inheritDoc}
    **/
    public void stopApp() {
        return;
    }

    /**
    *	{@inheritDoc}
    **/
    public Service getInterface() {
        return this;
    }

    /**
    *	{@inheritDoc}
    **/
    public Advertisement getImplAdvertisement() {
        return implAdv;
    }

    /***********************************************************
     ** PeerGroup API
     ***********************************************************/

    /**
    *	{@inheritDoc}
    **/
    public ThreadGroup getHomeThreadGroup() {
        if (group != null) {
            return group.getHomeThreadGroup();
        } else {
            return null;
        }
    }

    /***********************************************************
     ** PeerGroup API
     ***********************************************************/

    /**
    *	{@inheritDoc}
    **/
    public URI getStoreHome() {
        if (group != null) {
            return group.getStoreHome();
        } else {
            return null;
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public JxtaLoader getLoader() {
        if (group != null) {
            return group.getLoader();
        } else {
            return null;
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public PeerGroup getParentGroup() {

        try {
            return (PeerGroup) group;
        } catch (Exception ex) {
            if ( LOG.isEnabledFor(Level.DEBUG) ) {
                LOG.debug("LightWeightPeerGroup is a base PeerGroup: no parent");
            }
            throw new RuntimeException ("LightWeightPeerGroup is a base PeerGroup: no parent");
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public boolean isRendezvous() {

        if (group != null) {
            return group.isRendezvous();
        } else {
            return false;
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public PeerGroupAdvertisement getPeerGroupAdvertisement() {

        if (adv != null) {
            return adv;
        } else if (group != null) {
            return group.getPeerGroupAdvertisement();
        } else {
            return null;
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public PeerAdvertisement getPeerAdvertisement() {

        if (group != null) {
            return group.getPeerAdvertisement();
        } else {
            return null;
        }
    }

    /**
    *	{@inheritDoc}
    **/
    public Service lookupService(ID name) throws ServiceNotFoundException {

        if (group != null) {
            return group.lookupService (name);
        } else {
            throw new ServiceNotFoundException ("Not implemented");
        }
    }

    /**
     *	{@inheritDoc}
     **/
    public Service lookupService(ID name, int ignoredForNow) throws ServiceNotFoundException {

        if (group != null) {
            return group.lookupService (name);
        } else {
            throw new ServiceNotFoundException ("Not implemented");
        }