org.universAAL.lddi.abstraction

Class CommunicationGateway

java.lang.Object

org.universAAL.lddi.abstraction.CommunicationGateway

public abstract class CommunicationGateway
extends Object

A gateway providing a bridge to a network of external components making it for component integrators possible to gain access to related external datapoints. For a better understanding, please refer to both the package documentation and the documentation of the methods further below.

Constructor Summary

Constructors

Constructor and Description
CommunicationGateway()

Method Summary

Modifier and Type	Method and Description
abstract Object	readValue(ExternalDatapoint datapoint) component integrators can use this method to get the value of a given property of a given external component by specifying the related external datapoint.
abstract void	register(String componentTypeURI, ComponentIntegrator integrator) To be used by component integrators to register to this gateway for external components of the given type.
abstract int	startEventing(ComponentIntegrator integrator, ExternalComponent component, byte intervalSeconds) Serves as means for subscribing for events related to the changes of the value of any property of the given external component.
abstract int	startEventing(ComponentIntegrator integrator, ExternalDatapoint datapoint, byte intervalSeconds) Serves as means for subscribing for events related to the changes of the value of a given property of a given external component by specifying the related external datapoint.
abstract int	startEventing(ComponentIntegrator integrator, String componentTypeURI, String propURI, byte intervalSeconds) If the given property URI is not null, serves as means for subscribing for events related to the changes of the value of the given property of any external component of the given type; otherwise, with propURI == null, it can be used to subscribe for the changes of the value of any property of any external component of the given type.
abstract void	stopEventing(int eventingID) component integrators can use this method to unsubscribe a subscription done previously.
abstract void	writeValue(ExternalDatapoint datapoint, Object value) component integrators can use this method to change the value of a given property of a given external component by specifying the related external datapoint and the new value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CommunicationGateway

public CommunicationGateway()

Method Detail

register

public abstract void register(String componentTypeURI,
                              ComponentIntegrator integrator)

To be used by component integrators to register to this gateway for external components of the given type. The implementation must (1) add the given integrator to the list of integrators interested in the given type of components, and (2) call the related notification method of the integrator with the list of components of the given type, both for those already known at the time of registration and at any time in future when new components of the same type are added to the external network.

startEventing

public abstract int startEventing(ComponentIntegrator integrator,
                                  ExternalDatapoint datapoint,
                                  byte intervalSeconds)

Serves as means for subscribing for events related to the changes of the value of a given property of a given external component by specifying the related external datapoint. Note that this implies that the external components made known by gateways to integrators must include the property mapping to datapoints.

To be used by component integrators to inform this gateway about the interest to be notified as soon as the value of the given external datapoint changes. The implementation must (1) add the given integrator to the list of integrators interested in the same kind of events, and (2) call the related notification method of the integrator both with the current value at the time of registration and at any time in future when the value changes.

Parameters:

integrator - the integrator registing for notification.

datapoint - the datapoint whose changes of values must fire events.

intervalSeconds - needed when the external communication protocol doesn't support "real-time" eventing and hence the gateway has to implement the eventing mechanism by pulling the value every n seconds and check if it has changed or not. In that case, this parameter indicates the related preference of the integrator.

Returns:

An ID for this subscription so that integrators can unsubscribe later if need be.

startEventing

public abstract int startEventing(ComponentIntegrator integrator,
                                  ExternalComponent component,
                                  byte intervalSeconds)

Serves as means for subscribing for events related to the changes of the value of any property of the given external component. Compared to startEventing(ComponentIntegrator, ExternalDatapoint, byte), it wildcards all datapoints within the scope of the given external component.

See Also:

startEventing(ComponentIntegrator, ExternalDatapoint, byte)

startEventing

public abstract int startEventing(ComponentIntegrator integrator,
                                  String componentTypeURI,
                                  String propURI,
                                  byte intervalSeconds)

If the given property URI is not null, serves as means for subscribing for events related to the changes of the value of the given property of any external component of the given type; otherwise, with propURI == null, it can be used to subscribe for the changes of the value of any property of any external component of the given type. Compared to startEventing(ComponentIntegrator, ExternalDatapoint, byte), it wildcards all datapoints within the scope of all external components of the given type, either by selecting those that correspond to a given property or not.

See Also:

startEventing(ComponentIntegrator, ExternalDatapoint, byte)

stopEventing

public abstract void stopEventing(int eventingID)

component integrators can use this method to unsubscribe a subscription done previously.

Parameters:

eventingID - the ID returned previously when calling startEventing( ComponentIntegrator, ExternalDatapoint, byte) or any of the wildcarding versions of it.

readValue

public abstract Object readValue(ExternalDatapoint datapoint)

component integrators can use this method to get the value of a given property of a given external component by specifying the related external datapoint. Note that this implies that the external components made known by gateways to integrators must include the property mapping to datapoints.

writeValue

public abstract void writeValue(ExternalDatapoint datapoint,
                                Object value)

component integrators can use this method to change the value of a given property of a given external component by specifying the related external datapoint and the new value. Note that this implies that the external components made known by gateways to integrators must include the property mapping to datapoints.