Project JXTA

net.jxta.peergroup
Class LightWeightPeerGroup

java.lang.Object
  extended bynet.jxta.peergroup.LightWeightPeerGroup
All Implemented Interfaces:
Module, PeerGroup, Service

public class LightWeightPeerGroup
extends Object
implements PeerGroup

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.


Nested Class Summary
 
Nested classes inherited from class net.jxta.peergroup.PeerGroup
PeerGroup.GlobalRegistry
 
Field Summary
 
Fields inherited from interface net.jxta.peergroup.PeerGroup
accessClassID, allPurposePeerGroupSpecID, applicationClassID, Both, DEFAULT_EXPIRATION, DEFAULT_LIFETIME, discoveryClassID, endpointClassID, FromParent, globalRegistry, Here, httpProtoClassID, membershipClassID, peerGroupClassID, peerinfoClassID, pipeClassID, proxyClassID, refAccessSpecID, refDiscoverySpecID, refEndpointSpecID, refHttpProtoSpecID, refMembershipSpecID, refNetPeerGroupSpecID, refPeerinfoSpecID, refPipeSpecID, refPlatformSpecID, refProxySpecID, refRelayProtoSpecID, refRendezvousSpecID, refResolverSpecID, refRouterProtoSpecID, refShellSpecID, refStartNetPeerGroupSpecID, refTcpProtoSpecID, refTlsProtoSpecID, relayProtoClassID, rendezvousClassID, resolverClassID, routerProtoClassID, tcpProtoClassID, tlsProtoClassID, WK_ID_PREFIX
 
Fields inherited from interface net.jxta.platform.Module
START_AGAIN_PROGRESS, START_AGAIN_STALLED, START_OK
 
Constructor Summary
LightWeightPeerGroup(PeerGroupAdvertisement adv)
          Constructor All classes that extend this class must invoke this constructor.
 
Method Summary
 boolean compatible(Element compat)
          Return true if the provided compatibility statement is compatible with this group.
 AccessService getAccessService()
          Return the Access Service for this Peer Group. This service is present in every Peer Group.
 ModuleImplAdvertisement getAllPurposePeerGroupImplAdvertisement()
          Get an all purpose peerGroup ModuleImplAdvertisement that is compatible with this group. This impl adv can be used to create any group that relies only on the standard services. Or to derive other impl advs, using this impl advertisement as a basis.
 ConfigParams getConfigAdvertisement()
          Returns the config advertisment for this peer in this group (if any).
 DiscoveryService getDiscoveryService()
          Return the Discovery Service for this Peer Group.
 EndpointService getEndpointService()
          Return the Endpoint Service for this Peer Group. This service is present in every Peer Group.
 ThreadGroup getHomeThreadGroup()
          Returns the Thread Group in which threads for this peer group will live. This is currently used only for debugging purposes so that the source of a thread can be determined.
 Advertisement getImplAdvertisement()
          Returns the advertisment for this service.
 Service getInterface()
          Service objects are not manipulated directly to protect usage of the service. A Service interface is returned to access the service methods.
 JxtaLoader getLoader()
          Returns the class loader for this group.
 MembershipService getMembershipService()
          Return the Membership Service for this Peer Group. This service is present in every Peer Group.
 PeerGroup getParentGroup()
          Returns the parent group of this group. Not all groups have parents and some implementations may not reveal their parents.
 PeerAdvertisement getPeerAdvertisement()
          Return the PeerAdvertisement of the local Peer within this Peer Group.
 PeerGroupAdvertisement getPeerGroupAdvertisement()
          Return the PeerGroupAdvertisement for this group.
 PeerGroupID getPeerGroupID()
          Return the Peer Group ID of this Peer Group.
 String getPeerGroupName()
          Return the Name of this group. This name is not canonical, meaning that there may be other groups with the same name.
 PeerID getPeerID()
          Return the Peer ID by which this Peer is known within this Peer Group.
 PeerInfoService getPeerInfoService()
          Return the PeerInfo Service for this Peer Group.
 String getPeerName()
          Return the name of the local peer within this group. This name is not canonical, meaning that there may be other peers with the same name.
 PipeService getPipeService()
          Return the Pipe Service for this Peer Group.
 RendezVousService getRendezVousService()
          Return the Rendezvous Service for this Peer Group. This service is optional and may not be present in all groups.
 ResolverService getResolverService()
          Return the Resolver Service for this Peer Group. This service is present in every Peer Group.
 Iterator getRoleMap(ID name)
          Returns the map of the assigned IDs currently associated with the given ModuleClassID by this PeerGroup object. The IDs are returned in the order of their index in the map. So the first ID returned will be identical to what would be returned by the lookup method for the given ID and index 0. If there is no explicit such map, this method will return a singleton containing the given ID as this is the default mapping. There is no guarantee that any of the returned IDs correspond to an actually registered service. This method only maps IDs.
 PeerGroup getWeakInterface()
          Returns a weak interface object that represents this group.

A weak interface object has no life-cycle privileges over the group that it represents and therefore its users have no accountability. A weak interface object is safe to give away but holds no promise of sustained validity.

Whatever code gave away a weak interface object retains the power of terminating the group object from which it was obtained, thereby making the weak interface object invalid.

A weak interface object is immutable; its unref and stopApp methods do nothing. Its validity is exactly that of the group or interface object from which it was obtained.

A weak interface object can be obtained from an interface object, or from a real group object, or from a weak interface object. In the later case, the object returned may be the original weak interface object since such objects are immutable.

Whatever code obtains a weak interface object from a group object or regular interface object, remains entirely liable for invoking unref on the initial object before discarding it. Giving away a weak interface object is not equivalent to transfering ownerhsip of the original.

 void init(PeerGroup group, ID assignedID, Advertisement implAdv)
          Initialize the module, passing it its peer group and advertisement.

Note: when subclassing one of the existing PeerGroup implementations (which implement Module), it may not be recommended to overload the init method. See the documentation of the PeerGroup class being subclassed.

 boolean isRendezvous()
          Returns the whether the group member is a Rendezvous peer for the group.
 Module loadModule(ID assignedID, Advertisement impl)
          Load a module from a ModuleImplAdv. Compatibility is checked and load is attempted. If compatible and loaded successfuly, the resulting Module is initialized and returned. In most cases the other loadModule() method should be preferred, since unlike this one, it will seek many compatible implementation advertisements and try them all until one works. The home group of the new module (its parent group if the new module is a group) will be this group.
 Module loadModule(ID assignedID, ModuleSpecID specID, int where)
          Load a module from a spec id. Advertisement is sought, compatibility is checked on all candidates and load is attempted. The first one that is compatible and loads successfuly is initialized and returned.
 Service lookupService(ID name)
          Lookup for a service by name.
 Service lookupService(ID name, int ignoredForNow)
          Lookup for a service by class ID and index in a map. More than one service in a group may be of a given ModuleClass. However each of them has a unique assigned ID which serves as the index in the map of services. In most cases, there is only one service of each given Module Class, and the ID of that Module Class is the assigned ID. Otherwise, the group may have a list of existing assigned ID per base class. This routine may be used to retrieve services of the given Module Class and index in that list. In the absence of a mapping, index 0 is still valid and corresponds to the service which assigned ID is exactly the given ID. Group objects with a map are normaly wrappers taylored specially by the loader of a module (often the group itself) in order to provide a map appropriate for that module. Modules that do not use more than one service of a given base class normally never need to call this method; lookupService(ID) is equivalent to lookupService(ID, 0) and will transparently remap index 0 to whatever the group's structure defines as the default for the invoking service. Note: traditionaly, the given ID is expected to be a base Module Class ID, and the assigned ID of a Module is a Class ID of the same base class with a role suffix to make it unique. If the given ID already contains a role suffix, there may exist an entry for it in the map anyway, if not (which is the expected use pattern), then only index 0 exists and the given ID is used whole and untranslated.
 PeerGroup newGroup(Advertisement pgAdv)
          Instantiate a peer group from its given advertisement. This instantiator requires that the ModuleImplAdvertisment for the peer group and the ModuleImplAdvertisements for the group's services be available for discovery within the current group.

The pgAdv itself may be all new and unpublished. Therefore, the two typical uses of this routine are:

  • Creating an all new group with a new ID while using an existing and published implementation. (Possibly a new one published for that purpose). The information should first be gathered in a new PeerGroupAdvertisement which is then passed to this method.
  • Instantiating a group which advertisement has already been discovered (therefore there is no need to find it by groupID again).

To create a group from a known implAdv, use PeerGroup.newGroup(PeerGroupID,Advertisement,String,String)

 PeerGroup newGroup(PeerGroupID gid)
          Instantiate a group from its Peer Group ID only. Use this when using a group that has already been published and discovered.

The typical uses of this routine are therefore:

  • Instantiating a peer group which is assumed to exist and whose Peer Group ID is already known.
  • Creating a new peer group instance using an already published Group advertisement, typically published for that purpose. All other referenced advertisements must also be available.

To create a group from a known implAdv, just use PeerGroup.loadModule(ID,Advertisement) or even:

grp = new GroupSubClass(); grp.init(parentGroup, gid, impladv);

then, REMEMBER TO PUBLISH THE GROUP IF IT IS ALL NEW.

 PeerGroup newGroup(PeerGroupID gid, Advertisement impl, String name, String description)
          Instantiates a new group from its elementary pieces and publishes the corresponding PeerGroupAdvertisement. The pieces are: the groups implementation adv, the group id, the name and description.

The typical use of this routine is creating a whole new group based on a newly created and possibly unpublished implementation adv.

This is a convenience method equivalent to either:

 newGrp = thisGroup.loadModule(gid, impl);
 newGrp.publishGroup(name, description);
 

or, but only if the implementation advertisement has been published:

 newPGAdv = AdvertisementFactory.newAdvertisement(
                 PeerGroupAdvertisement.getAdvertisementType());
 newPGAdv.setPeerGroupID(gid);
 newPGAdv.setModuleSpecID(impl.getModuleSpecID());
 newPGAdv.setName(name);
 newPGAdv.setDescription(description);
 newGrp = thisGroup.newGroup(newPGAdv);
 
 void publishGroup(String name, String description)
          Publish this group's Peer Group Advertisment if it has not already been published. The Peer Group Advertisement is published into the Peer Group in which this group was instantiated, specifically the Peer Group whose newGroup() was called.

Calling this method is only useful if the group is being created from scratch and the PeerGroup advertisement has not been created beforehand. In such a case, the group has never been named or described. Therefore this information has to be supplied here.

If this group has already been previously published, this method does nothing.

 int startApp(String[] args)
          Complete any remaining initialization of the module. The module should be fully functional after startApp() is completed. That is also the opportunity to supply arbitrary arguments (mostly to applications).

If this module is a PeerGroup service, it may be invoked several times depending on its return value.

 void stopApp()
          Stop a module. This may be called any time after init() completes and should not assume that startApp() has been called or completed.

The Module cannot be forced to comply, but in the future we might be able to deny it access to anything after some timeout.

 void unref()
          Explicitly notifies a group interface that it will no-longer be used (similar to dispose). Does nothing to a real group object, only has an effect on a group interface.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

LightWeightPeerGroup

public LightWeightPeerGroup(PeerGroupAdvertisement adv)
Constructor All classes that extend this class must invoke this constructor.

Parameters:
adv - PeerGroupAdvertisement of this LightWeightPeerGroup. Note that only the PeerGroupID is used.
Method Detail

init

public void init(PeerGroup group,
                 ID assignedID,
                 Advertisement implAdv)
Initialize the module, passing it its peer group and advertisement.

Note: when subclassing one of the existing PeerGroup implementations (which implement Module), it may not be recommended to overload the init method. See the documentation of the PeerGroup class being subclassed.

Specified by:
init in interface Module
Parameters:
group - The PeerGroup from which this Module can obtain services. If this module is a Service, this is also the PeerGroup of which this module is a service.
assignedID - Identity of Module within group. modules can use it as a the root of their namespace to create names that are unique within the group but predictible by the same module on another peer. This is normaly the ModuleClassID which is also the name under which the module is known by other modules. For a group it is the PeerGroupID itself. The parameters of a service, in the Peer configuration, are indexed by the assignedID of that service, and a Service must publish its run-time parameters in the Peer Advertisement under its assigned ID.
implAdv - The implementation advertisement for this Module. It is permissible to pass null if no implementation advertisement is available. This may happen if the implementation was selected by explicit class name rather than by following an implementation advertisement. Modules are not required to support that style of loading, but if they do, then their documentation should mention it.

startApp

public int startApp(String[] args)
Complete any remaining initialization of the module. The module should be fully functional after startApp() is completed. That is also the opportunity to supply arbitrary arguments (mostly to applications).

If this module is a PeerGroup service, it may be invoked several times depending on its return value.

Specified by:
startApp in interface Module
Parameters:
args - An array of Strings forming the parameters for this Module.
Returns:
int A status indication which may be one of Module.START_OK, Module.START_AGAIN_PROGRESS, Module.START_AGAIN_STALLED, which indicates partial or complete success, or any other value (negative values are recommended for future compatibility), which indicates failure.

stopApp

public void stopApp()
Stop a module. This may be called any time after init() completes and should not assume that startApp() has been called or completed.

The Module cannot be forced to comply, but in the future we might be able to deny it access to anything after some timeout.

Specified by:
stopApp in interface Module

getInterface

public Service getInterface()
Service objects are not manipulated directly to protect usage of the service. A Service interface is returned to access the service methods.

Specified by:
getInterface in interface Service
Returns:
Service public interface of the service

getImplAdvertisement

public Advertisement getImplAdvertisement()
Returns the advertisment for this service.

Specified by:
getImplAdvertisement in interface Service
Returns:
Advertisement the advertisement.

getHomeThreadGroup

public ThreadGroup getHomeThreadGroup()
Returns the Thread Group in which threads for this peer group will live. This is currently used only for debugging purposes so that the source of a thread can be determined.

Specified by:
getHomeThreadGroup in interface PeerGroup
Returns:
ThreadGroup

getLoader

public JxtaLoader getLoader()
Returns the class loader for this group.

Specified by:
getLoader in interface PeerGroup
Returns:
JxtaLoader The JXTA Class loader used by this group.

getParentGroup

public PeerGroup getParentGroup()
Returns the parent group of this group. Not all groups have parents and some implementations may not reveal their parents.

Specified by:
getParentGroup in interface PeerGroup
Returns:
PeerGroup the parent group or null if a parent group if not available.

isRendezvous

public boolean isRendezvous()
Returns the whether the group member is a Rendezvous peer for the group.

Specified by:
isRendezvous in interface PeerGroup
Returns:
boolean true if the peer is a rendezvous for the group.

getPeerGroupAdvertisement

public PeerGroupAdvertisement getPeerGroupAdvertisement()
Return the PeerGroupAdvertisement for this group.

Specified by:
getPeerGroupAdvertisement in interface PeerGroup
Returns:
PeerGroupAdvertisement this Group's advertisement.

getPeerAdvertisement

public PeerAdvertisement getPeerAdvertisement()
Return the PeerAdvertisement of the local Peer within this Peer Group.

Specified by:
getPeerAdvertisement in interface PeerGroup
Returns:
the PeerAdvertisement of the local Peer within this Peer Group.

lookupService

public Service lookupService(ID name)
                      throws ServiceNotFoundException
Lookup for a service by name.

Specified by:
lookupService in interface PeerGroup
Parameters:
name - the service identifier.
Returns:
Service, the Service registered by that name
Throws:
ServiceNotFoundException - could not find the service requested

lookupService

public Service lookupService(ID name,
                             int ignoredForNow)
                      throws ServiceNotFoundException
Lookup for a service by class ID and index in a map. More than one service in a group may be of a given ModuleClass. However each of them has a unique assigned ID which serves as the index in the map of services. In most cases, there is only one service of each given Module Class, and the ID of that Module Class is the assigned ID. Otherwise, the group may have a list of existing assigned ID per base class. This routine may be used to retrieve services of the given Module Class and index in that list. In the absence of a mapping, index 0 is still valid and corresponds to the service which assigned ID is exactly the given ID. Group objects with a map are normaly wrappers taylored specially by the loader of a module (often the group itself) in order to provide a map appropriate for that module. Modules that do not use more than one service of a given base class normally never need to call this method; lookupService(ID) is equivalent to lookupService(ID, 0) and will transparently remap index 0 to whatever the group's structure defines as the default for the invoking service. Note: traditionaly, the given ID is expected to be a base Module Class ID, and the assigned ID of a Module is a Class ID of the same base class with a role suffix to make it unique. If the given ID already contains a role suffix, there may exist an entry for it in the map anyway, if not (which is the expected use pattern), then only index 0 exists and the given ID is used whole and untranslated.

Specified by:
lookupService in interface PeerGroup
Parameters:
name - the service identifier
ignoredForNow - the index in the list of assigned IDs that match that identifier.
Returns:
Service, the corresponding Service
Throws:
ServiceNotFoundException - Could not find the service requested.

getRoleMap

public Iterator getRoleMap(ID name)
Returns the map of the assigned IDs currently associated with the given ModuleClassID by this PeerGroup object. The IDs are returned in the order of their index in the map. So the first ID returned will be identical to what would be returned by the lookup method for the given ID and index 0. If there is no explicit such map, this method will return a singleton containing the given ID as this is the default mapping. There is no guarantee that any of the returned IDs correspond to an actually registered service. This method only maps IDs.

Specified by:
getRoleMap in interface PeerGroup
Parameters:
name - The ModuleClassID for which the map is desired.
Returns:
Iterator An iterator on a collection of the IDs to which the given ID maps.

compatible

public boolean compatible(Element compat)
Return true if the provided compatibility statement is compatible with this group.

Specified by:
compatible in interface PeerGroup
Returns:
boolean True if the statement is compatible.

loadModule

public Module loadModule(ID assignedID,
                         Advertisement impl)
                  throws ProtocolNotSupportedException,
                         PeerGroupException
Load a module from a ModuleImplAdv. Compatibility is checked and load is attempted. If compatible and loaded successfuly, the resulting Module is initialized and returned. In most cases the other loadModule() method should be preferred, since unlike this one, it will seek many compatible implementation advertisements and try them all until one works. The home group of the new module (its parent group if the new module is a group) will be this group.

Specified by:
loadModule in interface PeerGroup
Parameters:
assignedID - Id to be assigned to that module (usually its ClassID).
impl - An implementation advertisement for that module.
Returns:
Module the module loaded and initialized.
Throws:
PeerGroupException - The module could not be loaded or initialized
ProtocolNotSupportedException - The module is a protocol and is disabled per the peer's configuration.

loadModule

public Module loadModule(ID assignedID,
                         ModuleSpecID specID,
                         int where)
Load a module from a spec id. Advertisement is sought, compatibility is checked on all candidates and load is attempted. The first one that is compatible and loads successfuly is initialized and returned.

Specified by:
loadModule in interface PeerGroup
Parameters:
assignedID - Id to be assigned to that module (usually its ClassID).
specID - The specID of this module.
where - May be one of: Here, FromParent, or Both, meaning that the implementation advertisement will be searched in this group, its parent or both. As a general guideline, the implementation advertisements of a group should be searched in its propsective parent (that is Here), the implementation advertisements of a group standard service should be searched in the same group than where this group's advertisement was found (that is, FromParent), while applications may be sought more freely (Both).
Returns:
Module the new module, or null if no usuable implementation was found.

publishGroup

public void publishGroup(String name,
                         String description)
                  throws IOException
Publish this group's Peer Group Advertisment if it has not already been published. The Peer Group Advertisement is published into the Peer Group in which this group was instantiated, specifically the Peer Group whose newGroup() was called.

Calling this method is only useful if the group is being created from scratch and the PeerGroup advertisement has not been created beforehand. In such a case, the group has never been named or described. Therefore this information has to be supplied here.

If this group has already been previously published, this method does nothing.

Specified by:
publishGroup in interface PeerGroup
Parameters:
name - The name of this group.
description - The description of this group.
Throws:
IOException - The publication could not be accomplished because of a network or storage failure.

newGroup

public PeerGroup newGroup(Advertisement pgAdv)
                   throws PeerGroupException
Instantiate a peer group from its given advertisement. This instantiator requires that the ModuleImplAdvertisment for the peer group and the ModuleImplAdvertisements for the group's services be available for discovery within the current group.

The pgAdv itself may be all new and unpublished. Therefore, the two typical uses of this routine are:

To create a group from a known implAdv, use PeerGroup.newGroup(PeerGroupID,Advertisement,String,String)

Specified by:
newGroup in interface PeerGroup
Parameters:
pgAdv - The advertisement for the group to be instantiated.
Returns:
PeerGroup the initialized (but not started) peergroup.
Throws:
PeerGroupException - The group could not be instantated.

newGroup

public PeerGroup newGroup(PeerGroupID gid,
                          Advertisement impl,
                          String name,
                          String description)
                   throws PeerGroupException
Instantiates a new group from its elementary pieces and publishes the corresponding PeerGroupAdvertisement. The pieces are: the groups implementation adv, the group id, the name and description.

The typical use of this routine is creating a whole new group based on a newly created and possibly unpublished implementation adv.

This is a convenience method equivalent to either:

 newGrp = thisGroup.loadModule(gid, impl);
 newGrp.publishGroup(name, description);
 

or, but only if the implementation advertisement has been published:

 newPGAdv = AdvertisementFactory.newAdvertisement(
                 PeerGroupAdvertisement.getAdvertisementType());
 newPGAdv.setPeerGroupID(gid);
 newPGAdv.setModuleSpecID(impl.getModuleSpecID());
 newPGAdv.setName(name);
 newPGAdv.setDescription(description);
 newGrp = thisGroup.newGroup(newPGAdv);
 

Specified by:
newGroup in interface PeerGroup
Parameters:
gid - The ID of that group. If null then a new group ID will be chosen.
impl - The advertisement of the implementation to be used.
name - The name of the group.
description - A description of this group.
Returns:
PeerGroup the initialized (but not started) peergroup.
Throws:
PeerGroupException - The group could ne be instantiated.

newGroup

public PeerGroup newGroup(PeerGroupID gid)
                   throws PeerGroupException
Instantiate a group from its Peer Group ID only. Use this when using a group that has already been published and discovered.

The typical uses of this routine are therefore:

To create a group from a known implAdv, just use PeerGroup.loadModule(ID,Advertisement) or even:

grp = new GroupSubClass(); grp.init(parentGroup, gid, impladv);

then, REMEMBER TO PUBLISH THE GROUP IF IT IS ALL NEW.

Specified by:
newGroup in interface PeerGroup
Parameters:
gid - the groupID.
Returns:
PeerGroup the initialized (but not started) peergroup.
Throws:
PeerGroupException - The group could ne be instantated.

getRendezVousService

public RendezVousService getRendezVousService()
Return the Rendezvous Service for this Peer Group. This service is optional and may not be present in all groups.

Specified by:
getRendezVousService in interface PeerGroup
Returns:
The Rendezvous Service for this Peer Group or null if there is no Rendezvous Service in this Peer Group.

getEndpointService

public EndpointService getEndpointService()
Return the Endpoint Service for this Peer Group. This service is present in every Peer Group.

Specified by:
getEndpointService in interface PeerGroup
Returns:
EndpointService The Endpoint Service for this Peer Group.

getResolverService

public ResolverService getResolverService()
Return the Resolver Service for this Peer Group. This service is present in every Peer Group.

Specified by:
getResolverService in interface PeerGroup
Returns:
ResolverService The Resolver Service for this Peer Group.

getDiscoveryService

public DiscoveryService getDiscoveryService()
Return the Discovery Service for this Peer Group.

Specified by:
getDiscoveryService in interface PeerGroup
Returns:
The Discovery Service for this Peer Group or null if there is no PeerInfo Service in this Peer Group.

getPeerInfoService

public PeerInfoService getPeerInfoService()
Return the PeerInfo Service for this Peer Group.

Specified by:
getPeerInfoService in interface PeerGroup
Returns:
The PeerInfo Service for this Peer Group or null if there is no PeerInfo Service in this Peer Group.

getMembershipService

public MembershipService getMembershipService()
Return the Membership Service for this Peer Group. This service is present in every Peer Group.

Specified by:
getMembershipService in interface PeerGroup
Returns:
MembershipService The Membership Service for this Peer Group.

getPipeService

public PipeService getPipeService()
Return the Pipe Service for this Peer Group.

Specified by:
getPipeService in interface PeerGroup
Returns:
The Pipe Service for this Peer Group or null if there is no Pipe Service in this Peer Group.

getAccessService

public AccessService getAccessService()
Return the Access Service for this Peer Group. This service is present in every Peer Group.

Specified by:
getAccessService in interface PeerGroup
Returns:
AccessService The Access Service for this Peer Group.

getPeerGroupID

public PeerGroupID getPeerGroupID()
Return the Peer Group ID of this Peer Group.

Specified by:
getPeerGroupID in interface PeerGroup
Returns:
PeerGroupId The Peer Group ID of this Peer Group.

getPeerID

public PeerID getPeerID()
Return the Peer ID by which this Peer is known within this Peer Group.

Specified by:
getPeerID in interface PeerGroup
Returns:
the Peer ID by which this Peer is known within this Peer Group.

getPeerGroupName

public String getPeerGroupName()
Return the Name of this group. This name is not canonical, meaning that there may be other groups with the same name.

Specified by:
getPeerGroupName in interface PeerGroup
Returns:
String This groups's name or null if no name was specified.

getPeerName

public String getPeerName()
Return the name of the local peer within this group. This name is not canonical, meaning that there may be other peers with the same name.

Specified by:
getPeerName in interface PeerGroup
Returns:
String This peer's name or null if no name was specified.

getConfigAdvertisement

public ConfigParams getConfigAdvertisement()
Returns the config advertisment for this peer in this group (if any).

Specified by:
getConfigAdvertisement in interface PeerGroup
Returns:
The advertisement or null if none is available.

getAllPurposePeerGroupImplAdvertisement

public ModuleImplAdvertisement getAllPurposePeerGroupImplAdvertisement()
                                                                throws Exception
Get an all purpose peerGroup ModuleImplAdvertisement that is compatible with this group. This impl adv can be used to create any group that relies only on the standard services. Or to derive other impl advs, using this impl advertisement as a basis.

Specified by:
getAllPurposePeerGroupImplAdvertisement in interface PeerGroup
Returns:
ModuleImplAdvertisement the adv.
Throws:
Exception

unref

public void unref()
Explicitly notifies a group interface that it will no-longer be used (similar to dispose). Does nothing to a real group object, only has an effect on a group interface.

Specified by:
unref in interface PeerGroup

getWeakInterface

public PeerGroup getWeakInterface()
Returns a weak interface object that represents this group.

A weak interface object has no life-cycle privileges over the group that it represents and therefore its users have no accountability. A weak interface object is safe to give away but holds no promise of sustained validity.

Whatever code gave away a weak interface object retains the power of terminating the group object from which it was obtained, thereby making the weak interface object invalid.

A weak interface object is immutable; its unref and stopApp methods do nothing. Its validity is exactly that of the group or interface object from which it was obtained.

A weak interface object can be obtained from an interface object, or from a real group object, or from a weak interface object. In the later case, the object returned may be the original weak interface object since such objects are immutable.

Whatever code obtains a weak interface object from a group object or regular interface object, remains entirely liable for invoking unref on the initial object before discarding it. Giving away a weak interface object is not equivalent to transfering ownerhsip of the original.

Specified by:
getWeakInterface in interface PeerGroup
Returns:
PeerGroup A weak interface object that represents this PeerGroup object.

JXTA J2SE