From 613b275ffa5d7ae0c41b625db231c187b8a136ef Mon Sep 17 00:00:00 2001 From: antelder Date: Wed, 28 Oct 2009 09:54:25 +0000 Subject: Create 2.0 M4 release branch git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@830484 13f79535-47bb-0310-9956-ffa450edef68 --- .../osgi/remoteserviceadmin/EndpointListener.java | 112 +++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 branches/sca-java-2.0-M4/modules/node-impl-osgi/src/main/java/org/apache/tuscany/sca/osgi/remoteserviceadmin/EndpointListener.java (limited to 'branches/sca-java-2.0-M4/modules/node-impl-osgi/src/main/java/org/apache/tuscany/sca/osgi/remoteserviceadmin/EndpointListener.java') diff --git a/branches/sca-java-2.0-M4/modules/node-impl-osgi/src/main/java/org/apache/tuscany/sca/osgi/remoteserviceadmin/EndpointListener.java b/branches/sca-java-2.0-M4/modules/node-impl-osgi/src/main/java/org/apache/tuscany/sca/osgi/remoteserviceadmin/EndpointListener.java new file mode 100644 index 0000000000..94c08b7632 --- /dev/null +++ b/branches/sca-java-2.0-M4/modules/node-impl-osgi/src/main/java/org/apache/tuscany/sca/osgi/remoteserviceadmin/EndpointListener.java @@ -0,0 +1,112 @@ +package org.apache.tuscany.sca.osgi.remoteserviceadmin; + +/** + * A white board service that represents a listener for endpoints. + * + * An Endpoint Listener represents a participant in the distributed model that + * is interested in Endpoint Descriptions. + * + * 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 End Point + * Descriptions available in the network and inform the network about available + * End Point Descriptions. + * + * Both the network bundle and the manager bundle register an Endpoint + * Listener service. The manager informs the network bundle about End Points + * 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 End Point Description to all the End Point + * 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 {@link #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. given to it. + * + * 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. + * + * + * @ThreadSafe + */ +public interface EndpointListener { + /** + * Specifies the interest of this listener with filters. This listener is + * only interested in Endpoint Descriptions where its properties match the + * given filter. The type of this property must be String+. + */ + String ENDPOINT_LISTENER_SCOPE = "endpoint.listener.scope"; + + /** + * Register an endpoint with this listener. + * + * If the endpoint matches one of the filters registered with the + * {@link #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. + * + * @param endpoint + * The Endpoint Description to be published + * @param matchedFilter + * The filter from the {@link #ENDPOINT_LISTENER_SCOPE} that + * matched the endpoint, must not be null. + */ + void endpointAdded(EndpointDescription endpoint, String matchedFilter); + + /** + * Remove the registration of an endpoint. + * + * If an endpoint that was registered with the {@link #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. + * + * @param endpoint + * The Endpoint Description that is no longer valid. + * @param matchedFilter + * The filter from the {@link #ENDPOINT_LISTENER_SCOPE} that + * matched the endpoint, must not be null. + */ + void endpointRemoved(EndpointDescription endpoint, String matchedFilter); +} -- cgit v1.2.3