| org.cougaar.core.plugin.ComponentPlugin
 org.cougaar.servicediscovery.plugin.SimpleSDClientPlugin
All known Subclasses: org.cougaar.pizza.plugin.SDClientPlugin,
| SimpleSDClientPlugin | | public class SimpleSDClientPlugin extends ComponentPlugin (Code) | | Simple ServiceDiscovery ClientPlugin, responsible for initiating queries for services,
taking the resulting service pointer, and sending a Relay to the Provider requesting service.
Service Discovery is initiated by receiving a Find Providers task, and looking for the single Role
indicated on the AS Prepositional Phrase.
Sends a Disposition on the FindProviders Task when it gets a Relationship
with a provider for the service.
This Plugin is written to be extended (or copied). See the pizza module for an example of doing this.
Limitations: not quiescent aware, doesn't handle time-phased relationships,
not guaranteed to work with persistence and restarts, and assumes that providers
will not revoke relationships or otherwise change their mind.
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| Method Summary | |
| protected void | execute()
Issue MMQueries for FindProviders Tasks, ServiceContractRelays for responses to MMQueries,
and Dispositions on the FindProviders Tasks when those Relays are filled in with a Contract. | | protected DomainService | getDomainService()
Get the DomainService set by reflection, for getting pointers to Factories. | | protected UnaryPredicate | getFindProvidersPredicate()
Predicate to get the FindProviders Tasks. | | protected Entity | getLocalEntity()
Get the local (self) Entity - from a local cache, or by querying the Blackboard. | | protected PlanningFactory | getPlanningFactory()
| | protected Role | getRole(Task findProvidersTask)
Return the Role (indirect object) on the Constants.Prepositions.AS Prep Phrase in the given
FindProviders Task, if any -- this is the Provider Role we will look for. | | protected Role | getRole(ServiceDescription serviceDescription)
Retrieve the Role that the Provider is offering out of the ServiceDescription. | | protected SDFactory | getSDFactory()
Get the SDFactory. | | protected ServiceInfoScorer | getServiceInfoScorer(Role role, Task fpTask)
Create a scoring function to weigh different services registered in the YP, for use
by the Matchmaker. | | public void | load()
Load other services, particularly those not essential to operations. | | protected void | queryServices(Role role, Task findProvidersTask)
Send an
MMQueryRequest to the Matchmaker, requesting a provider
with the given
Role , satisfying the given Task. | | protected void | requestServiceContract(ServiceDescription serviceDescription)
Create and publish a relay with a service request for the specified Role, to the Provider
specified in the serviceDescription. | | public void | setDomainService(DomainService domainService)
| | protected void | setupSubscriptions()
Subscribe to MMRequests (requests to the Matchmaker),
ServiceContractRelays (where we'll get responses from the Providers),
and FindProviders Tasks (requests to us to do ServiceDiscovery). | | public void | unload()
| | protected void | updateFindProvidersTaskDispositions(Collection changedServiceContractRelays)
For each ServiceContractRelay that changes and has a ServiceContract, find the
un-disposed FindProviders Task that requested a Provider with the given Role, and
dispose it as succesful. |
| execute | | protected void execute()(Code) | | Issue MMQueries for FindProviders Tasks, ServiceContractRelays for responses to MMQueries,
and Dispositions on the FindProviders Tasks when those Relays are filled in with a Contract.
For each new FindProviders Task, issue an MMQuery to the Matchmaker, looking for the
specified Role.
If an MMQuery changes, issue a new ServiceContractRelay to the first named Provider
that was found.
If a ServiceContractRelay changes, update the Disposition on the original FindProviders
Task if we've now found a Provider for the needed Service.
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| getDomainService | | protected DomainService getDomainService()(Code) | | Get the DomainService set by reflection, for getting pointers to Factories.
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| getFindProvidersPredicate | | protected UnaryPredicate getFindProvidersPredicate()(Code) | | Predicate to get the FindProviders Tasks. In the off-chance that your verb is
slightly different, you can over-ride this method to point to your
domain-specific Verb Constant.
Note that it is not a constant, just so it can be over-ridden.
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| getLocalEntity | | protected Entity getLocalEntity()(Code) | | Get the local (self) Entity - from a local cache, or by querying the Blackboard.
the local (self) Entity |
| getRole | | protected Role getRole(Task findProvidersTask)(Code) | | Return the Role (indirect object) on the Constants.Prepositions.AS Prep Phrase in the given
FindProviders Task, if any -- this is the Provider Role we will look for.
Parameters:
findProvidersTask - Task which should contain an AS Prepositional Phrase Role on AS Phrase, indicate Role desired from ServiceDiscovery -- may be null |
| getRole | | protected Role getRole(ServiceDescription serviceDescription)(Code) | | Retrieve the Role that the Provider is offering out of the ServiceDescription.
Note that this assumes the role is under the CommercialServiceScheme, using the
Domain's Constants file. Extenders will over-ride this method.
Parameters:
serviceDescription - The Description of the Service as advertised in the YP. the Role advertised by the Provider, or null if none found. |
| getSDFactory | | protected SDFactory getSDFactory()(Code) | | Get the SDFactory. Factory for service discovery domain
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| getServiceInfoScorer | | protected ServiceInfoScorer getServiceInfoScorer(Role role, Task fpTask)(Code) | | Create a scoring function to weigh different services registered in the YP, for use
by the Matchmaker.
In this case, create a function that requires the given (Commercial) role.
Extenders of this plugin may over-ride this method to use a different function.
Parameters:
role - the Role to look for
Parameters:
fpTask - The FindProviders task this will satisfy the scoring function to hand the Matchmaker |
| load | | public void load()(Code) | | Load other services, particularly those not essential to operations.
In this case, use the DomainService to get Factories and release it.
Also get the Logging Service.
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| queryServices | | protected void queryServices(Role role, Task findProvidersTask)(Code) | | Send an
MMQueryRequest to the Matchmaker, requesting a provider
with the given
Role , satisfying the given Task.
Extenders of this plugin might choose to over-ride this method, though it usually will
not be necessary.
Parameters:
role - The Role to request
Parameters:
findProvidersTask - The Task whose request this will satisfy |
| requestServiceContract | | protected void requestServiceContract(ServiceDescription serviceDescription)(Code) | | Create and publish a relay with a service request for the specified Role, to the Provider
specified in the serviceDescription.
Parameters:
serviceDescription - the Matchmaker tells us about the possible service provider in this Service Description |
| setDomainService | | public void setDomainService(DomainService domainService)(Code) | | Used by the binding utility through reflection to set my DomainService
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| setupSubscriptions | | protected void setupSubscriptions()(Code) | | Subscribe to MMRequests (requests to the Matchmaker),
ServiceContractRelays (where we'll get responses from the Providers),
and FindProviders Tasks (requests to us to do ServiceDiscovery).
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| unload | | public void unload()(Code) | | Release any services retrieved during load() -- in this case, the LoggingService and DomainService
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| updateFindProvidersTaskDispositions | | protected void updateFindProvidersTaskDispositions(Collection changedServiceContractRelays)(Code) | | For each ServiceContractRelay that changes and has a ServiceContract, find the
un-disposed FindProviders Task that requested a Provider with the given Role, and
dispose it as succesful.
Assumes there will be one un-disposed FindProviders Task per Role.
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