JXTA in a Nutshell

Name

Package net.jxta.peergroup

Synopsis

Peergroups serve a number of purposes in JXTA. All peers belong to at least one peergroup (the NetPeerGroup); they are encouraged to discover (or create) and join other peergroups. Peergroups also scope JXTA operations: discovery of peers, pipes, or other services occurs only within the context of a given peergroup. Therefore, two peers that wish to communicate must join the same peergroup. Peergroups may optionally enforce membership restrictions and other security features.

Peergroups are self-organizing: any peer can create a new peergroup by creating the appropriate peergroup advertisement and publishing it. From a programming perspective, the peergroup object is created by taking a peergroup advertisement (whether created or discovered by the peer) and using it to initialize the peergroup object. Peergroups are named, which is how peers usually discover peergroups that they want to join.

Peergroups are created by providing the appropriate peer advertisement to the PeerGroupFactory class. The class hierarchy for this package is shown in Figure 9-11.

Figure 9-11. The net.jxta.peergroup package

Interfaces

public interface PeerGroup extends net.jxta.service.Service;

Classes

public static class PeerGroup.IdMaker;

public class PeerGroupFactory;

public abstract class PeerGroupID extends net.jxta.id.ID;