@ConsumerType public interface EndpointListener
EndpointEventListener
instead.
This white board service can be used in many different scenarios. However,
the primary use case is to allow a remote manager to be informed of Endpoint
Descriptions available in the network and inform the network about available
Endpoint Descriptions.
Both the network bundle and the manager bundle register an Endpoint Listener
service. The manager informs the network bundle about Endpoints that it
creates. The network bundles then uses a protocol like SLP to announce these
local end-points to the network.
If the network bundle discovers a new Endpoint through its discovery
protocol, then it sends an Endpoint Description to all the Endpoint Listener
services that are registered (except its own) that have specified an interest
in that endpoint.
Endpoint Listener services can express their scope with the service
property ENDPOINT_LISTENER_SCOPE
. This service property is a list of
filters. An Endpoint Description should only be given to a Endpoint Listener
when there is at least one filter that matches the Endpoint Description
properties.
This filter model is quite flexible. For example, a discovery bundle is only
interested in locally originating Endpoint Descriptions. The following filter
ensure that it only sees local endpoints.
(org.osgi.framework.uuid=72dc5fd9-5f8f-4f8f-9821-9ebb433a5b72)In the same vein, a manager that is only interested in remote Endpoint Descriptions can use a filter like:
(!(org.osgi.framework.uuid=72dc5fd9-5f8f-4f8f-9821-9ebb433a5b72))Where in both cases, the given UUID is the UUID of the local framework that can be found in the Framework properties. The Endpoint Listener's scope maps very well to the service hooks. A manager can just register all filters found from the Listener Hook as its scope. This will automatically provide it with all known endpoints that match the given scope, without having to inspect the filter string. In general, when an Endpoint Description is discovered, it should be dispatched to all registered Endpoint Listener services. If a new Endpoint Listener is registered, it should be informed about all currently known Endpoints that match its scope. If a getter of the Endpoint Listener service is unregistered, then all its registered Endpoint Description objects must be removed. The Endpoint Listener models a best effort approach. Participating bundles should do their utmost to keep the listeners up to date, but implementers should realize that many endpoints come through unreliable discovery processes.
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
ENDPOINT_LISTENER_SCOPE
Deprecated.
Specifies the interest of this listener with filters.
|
Modifier and Type | Method and Description |
---|---|
void |
endpointAdded(EndpointDescription endpoint,
java.lang.String matchedFilter)
Deprecated.
Register an endpoint with this listener.
|
void |
endpointRemoved(EndpointDescription endpoint,
java.lang.String matchedFilter)
Deprecated.
Remove the registration of an endpoint.
|
static final java.lang.String ENDPOINT_LISTENER_SCOPE
String+
.void endpointAdded(EndpointDescription endpoint, java.lang.String matchedFilter)
ENDPOINT_LISTENER_SCOPE
service property then this filter should
be given as the matchedFilter
parameter.
When this service is first registered or it is modified, it should
receive all known endpoints matching the filter.endpoint
- The Endpoint Description to be publishedmatchedFilter
- The filter from the ENDPOINT_LISTENER_SCOPE
that matched the endpoint, must not be null
.void endpointRemoved(EndpointDescription endpoint, java.lang.String matchedFilter)
endpointAdded(EndpointDescription, String)
method is no longer
available then this method should be called. This will remove the
endpoint from the listener.
It is not necessary to remove endpoints when the service is unregistered
or modified in such a way that not all endpoints match the interest
filter anymore.endpoint
- The Endpoint Description that is no longer valid.matchedFilter
- The filter from the ENDPOINT_LISTENER_SCOPE
that matched the endpoint, must not be null
.Copyright © OSGi Alliance (2000, 2018). All Rights Reserved. Licensed under the OSGi Specification License, Version 2.0