Package org.ws4d.java.service.reference

Implementation of listeners to be notified of changes of Service/Device references through the use of callback methods.

See:
Description

Interface Summary

DeviceListener	Interface to implement device reference listeners.
DeviceReference	Reference to a device.
Reference	Super interface of service and device reference.
ServiceListener	Callback interface for listeners interested in state changes of services.
ServiceReference	Interface of service reference.

Package org.ws4d.java.service.reference Description

Implementation of listeners to be notified of changes of Service/Device references through the use of callback methods.

The interfaces DeviceListener and ServiceListener implement a number of methods designated as callback methods to receive notifications for a given set of events emanating from a device or service (implementing classes are respectively DefaultService and DefaultDevice):

• For the Service, if it was changed, created or deleted
• For the Device, if it was changed, created, deleted and whether it is currently running

The interface Reference defines a protocol to obtain specific information about the service (hosting or hosted). The implementing classes DeviceReference and ServiceReference provide a specific interface for a device and for a service: with regards to the service, obtaining more information, and with regards to a device, methods to add or remove a listener (see DefaultClient for a listener class). Adding a listener will enable the client (listener) to receive information about device changes.

The implementing classes of ServiceReference and DeviceReference (see org.ws4d.java.dispatch ServiceReferenceHandler, DeviceReferenceHandler) make use of these callback methods informing listeners of a device or service change, and providing a Callback handler.