FileDocCategorySizeDatePackage
RestoPeer.javaAPI DocExample6176Wed May 08 22:25:34 BST 2002None

RestoPeer

public class RestoPeer extends Object

Fields Summary
private net.jxta.peergroup.PeerGroup
netpg
private net.jxta.peergroup.PeerGroup
restoNet
private String
brand
private int
timeout
private net.jxta.discovery.DiscoveryService
disco
private net.jxta.pipe.PipeService
pipes
static String
groupURL
Constructors Summary
Methods Summary
private voidjoinRestoNet()


        int count = 3;   // maximun number of attempts to discover
        System.out.println("Attempting to Discover the RestoNet PeerGroup");

        // Get the discovery service from the NetPeergroup
        DiscoveryService hdisco = netpg.getDiscoveryService();

        Enumeration ae = null;  // Holds the discovered peers

        // Loop until we discover the RestoNet or
        // until we've exhausted the desired number of attempts
        while (count-- > 0) {
            try {
                // search first in the peer local cache to find
                // the RestoNet peergroup advertisement
                ae = hdisco.getLocalAdvertisements(DiscoveryService.GROUP,
                                          "Name", "RestoNet");

                // If we found the RestoNet advertisement we are done
                if ((ae != null) && ae.hasMoreElements())
                    break;

                // If we did not find it, we send a discovery request
                hdisco.getRemoteAdvertisements(null,
                       DiscoveryService.GROUP, "Name", "RestoNet", 1, null);

                // Sleep to allow time for peers to respond to the
                // discovery request
                try {
                    Thread.sleep(timeout);
                } catch (InterruptedException ie) {}
            } catch (IOException e) {
                // Found nothing! Move on.
            }
        }

        PeerGroupAdvertisement restoNetAdv = null;

        // Check if we found the RestoNet advertisement.
        // If we didn't, then either
        //       we are the first peer to join or
        //       no other RestoNet peers are up.
        // In either case, we must create the RestoNet peergroup

        if (ae == null || !ae.hasMoreElements()) {
            System.out.println(
                 "Could not find the RestoNet peergroup; creating one");
            try {

                // Create a new, all-purpose peergroup.
                ModuleImplAdvertisement implAdv =
                    netpg.getAllPurposePeerGroupImplAdvertisement();
                restoNet = netpg.newGroup(
                                mkGroupID(),      // Assign new group ID
                                implAdv,          // The implem. adv
                                "RestoNet",       // Name of peergroup
                                "RestoNet, Inc.");// Description of peergroup

                // Get the PeerGroup Advertisement
                restoNetAdv = netpg.getPeerGroupAdvertisement();

            } catch (Exception e) {
                System.out.println("Error in creating RestoNet Peergroup");
                throw e;
            }
        } else {
            // The RestoNet advertisement was found in the cache;
            // that means we can join the existing RestoNet peergroup

            try {
                restoNetAdv = (PeerGroupAdvertisement) ae.nextElement();
                restoNet = netpg.newGroup(restoNetAdv);
                 System.out.println(
                     "Found the RestoNet Peergroup advertisement; joined existing group");
            } catch (Exception e) {
                System.out.println("Error in creating RestoNet PeerGroup from existing adv");
                throw e;
            }
        }

        try {
            // Get the discovery and pipe services for the RestoNet Peergroup
            disco = restoNet.getDiscoveryService();
            pipes = restoNet.getPipeService();
        } catch (Exception e) {
            System.out.println("Error getting services from RestoNet");
            throw e;
        }

        System.out.println("RestoNet Restaurant (" + brand + ") is on-line");
        return;
public static voidmain(java.lang.String[] args)

 

         
        RestoPeer myapp = new RestoPeer();
        myapp.startJxta();
        System.exit(0);
private net.jxta.peergroup.PeerGroupIDmkGroupID()

        return (PeerGroupID) IDFactory.fromURL(
             new URL("urn", "", groupURL));
private voidstartJxta()

        try {
            // Discover and join (or start) the default peergroup
            netpg = PeerGroupFactory.newNetPeerGroup();
        } catch (PeerGroupException e) {
            // Couldn't initialize; can't continue
            System.out.println("Fatal error : creating the net PeerGroup");
            System.exit(1);
        }

        // Discover (or create) and join the RestoNet peergroup
        try {
            joinRestoNet();
        } catch (Exception e) {
            System.out.println("Can't join or create RestoNet");
            System.exit(1);
        }

        // Wait for HungryPeers
        System.out.println("Waiting for HungryPeers");
        while (true) {
            // In later examples, HungryPeer requests are processed here
        }