lightweightpeergroup.java

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

/*
 * Copyright (c) 2003-2007 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.
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 *     and/or other materials provided with the distribution.
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 *  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.
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 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
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 *  http://www.jxta.org.
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package net.jxta.peergroup;


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.PeerGroupException;
import net.jxta.exception.ProtocolNotSupportedException;
import net.jxta.exception.ServiceNotFoundException;
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.ConfigParams;
import net.jxta.protocol.ModuleImplAdvertisement;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PeerGroupAdvertisement;
import net.jxta.rendezvous.RendezVousService;
import net.jxta.resolver.ResolverService;
import net.jxta.service.Service;
import java.util.logging.Level;
import net.jxta.logging.Logging;
import java.util.logging.Logger;

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


/**
 * LightWeightPeerGroup is a class intended to help
 * building PeerGroup that can inherit one or more
 * services from a parent PeerGroup.
 * <p/>
 * An LightWeightPeerGroup implements PeerGroup and is to
 * be used like a PeerGroup by applications.
 * <p/>
 * This class is intended to be extended/implemented.
 * <p/>
 * 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 ModuleImplAdvertisement implAdv = null;
    private final PeerGroupAdvertisement adv;

    /**
     * Constructor
     * <p/>
     * 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 = (ModuleImplAdvertisement) implAdv;
    }

    /**
     * {@inheritDoc}
     */
    public int startApp(String[] args) {
        if (null == group) {
            if (Logging.SHOW_SEVERE && LOG.isLoggable(Level.SEVERE)) {
                LOG.severe("No base peer group defined.");
            }
            return -1;
        }

        return START_OK;
    }

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

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

    /**
     * {@inheritDoc}
     */
    public ModuleImplAdvertisement 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 group;
        } catch (Exception ex) {
            if (Logging.SHOW_FINE && LOG.isLoggable(Level.FINE)) {
                LOG.fine("LightWeightPeerGroup is a base PeerGroup: no parent");
            }
            throw new RuntimeException("LightWeightPeerGroup is a base PeerGroup: no parent");
        }
    }

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

        return group != null && group.isRendezvous();
    }

    /**
     * {@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 {