startnetpeergroup.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: StartNetPeerGroup.java,v 1.46 2006/06/21 19:42:19 bondolo Exp $
 */

package net.jxta.impl.peergroup;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;
import net.jxta.id.ID;
import net.jxta.protocol.ModuleImplAdvertisement;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PeerGroupAdvertisement;
import net.jxta.discovery.DiscoveryService;
import net.jxta.peergroup.PeerGroup;
import net.jxta.peergroup.PeerGroupFactory;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
import net.jxta.platform.Application;
import net.jxta.exception.PeerGroupException;

/**
 * This code is responsible for configuring and starting the NetPeerGroup.
 *
 * <p/>Right now it starts an standard peergroup.
 *
 *  @deprecated The World Peer Group behaviour which starts the net peer group
 *  when the startApp() method has long been deprecated and hard to access given
 *  how PeerGroupFactory is commonly used. The StartNetPeerGroup behaviour will
 *  be removed in a future release.
 */
public class StartNetPeerGroup implements Application {

    PeerGroup pg;
    ID assignedID;
    Advertisement impl;

    /**
     *  {@inheritDoc}
     */
    public void stopApp() {}
                                                            
    private synchronized void delay() {
        try {
            wait(2000);
        } catch (Exception e) {}
    }

    /**
     *  {@inheritDoc}
     */
    public void init(PeerGroup pg, ID assignedID, Advertisement impl)
    throws PeerGroupException {
        this.pg = pg;
        this.assignedID = assignedID;
        this.impl = impl;
    }

    /**
     *  {@inheritDoc}
     */
    public int startApp(String[] arg) {
        try {
            // Attempt the recover the NetPeerGroup from a saved adv.
            PeerGroupAdvertisement npgAdv = null;

            // Look for the NetPeerGroup ADV on the net. In theory, there
            // should be some authoritative source for it. That is, whatever
            // advertisement named "NetPeerGroup" that you find, should describe
            // the same group with the same GID. In practice, for now, anyone
            // is an authoritative source, so there might be competing versions
            // seeded by different people who did not find any instance around
            // at some point in time and decided to seed it.

            BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

            // Offer the newbie mode; others know what to do.
            // That is, race against the boot to type "D<enter>"
            // before we run that code below...

            boolean doDisco = false;
            String answer = "";

            try {
                if (in.ready()) {
                    answer = in.readLine();
                    if (answer.equals("D")) {
                        doDisco = true;
                    }
                }
            } catch (Exception e) {}

            // If the user typed "D", we'll do discovery anyhow.
            // otherwise, we'll try to be smart; if there ever was
            // a NetPeerGroup other than the default instantiated
            // here, we'll assume that the user uses discovery for the
            // netPeerGroup. Otherwise, we'll assume that the user
            // just always uses the hardwired default.

            boolean beSmart = false;
            Hashtable advs = new Hashtable();
            boolean first = true;

            DiscoveryService disco = null;
            disco = pg.getDiscoveryService();

            // Until we find something or the user decides to make a choice.

            try {
                while (in.ready()) in.readLine();
            } catch (Exception e) {}

            int loop = 0;
            while (true) {
                try {
                    if (in.ready()) {
                        break;
                    }
                } catch (Exception e) {
                    break;
                }

                if (first) {
                    System.out.println("Looking for NetPeerGroup advertisements.");
                    if (doDisco) {
                        System.out.println("Press <enter> to stop looking and "
                                           + "choose.");
                    }
                }

                Enumeration ae = null;
                try {
                    if (first) {
                        ae = disco.getLocalAdvertisements(DiscoveryService.GROUP
                                                          , "Name"
                                                          , "NetPeerGroup");
                    } else {
                        if (loop++ % 5 == 0)
                            disco.getRemoteAdvertisements(null
                                                          , DiscoveryService.GROUP
                                                          , "Name"
                                                          , "NetPeerGroup",10);
                        delay();
                        ae = disco.getLocalAdvertisements(DiscoveryService.GROUP
                                                          , "Name"
                                                          , "NetPeerGroup");
                    }
                } catch (IOException e) {
                    // found nothing!  move on
                }


                first = false;
                while (ae != null && ae.hasMoreElements()) {
                    PeerGroupAdvertisement a =
                        (PeerGroupAdvertisement) ae.nextElement();

                    if (a.getName().equals("NetPeerGroup")) {
                        String kw = a.getDescription();
                        if (kw == null) kw = "";
                        if (! advs.containsKey(kw+a.getPeerGroupID().toString())) {
                            String self = " ";
                            // Do a quick lookup for a past local instantiation.
                            // May not find anything if we do not publish padvs
                            // in the parent grp.
                            Enumeration paEnum = (new Vector()).elements();