X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-binding-api%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fsal%2Fbinding%2Fapi%2FNotificationService.java;h=335f55bcbbade9ce84898eafee05ff146ef2d382;hp=46e372aea652e29439408da9b6d1ccc963e86acc;hb=c46e223995956f1f759c551163c212947c1e2fb7;hpb=af01f3ff581487d002140ca08a94e4636546d649

diff --git a/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/sal/binding/api/NotificationService.java b/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/sal/binding/api/NotificationService.java
index 46e372aea6..335f55bcbb 100644
--- a/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/sal/binding/api/NotificationService.java
+++ b/opendaylight/md-sal/sal-binding-api/src/main/java/org/opendaylight/controller/sal/binding/api/NotificationService.java
@@ -10,24 +10,108 @@ package org.opendaylight.controller.sal.binding.api;
 import org.opendaylight.yangtools.concepts.ListenerRegistration;
 import org.opendaylight.yangtools.yang.binding.Notification;
 
+/**
+ * Notification broker which allows clients to subscribe for and publish YANG-modeled notifications.
+ *
+ *<p>
+ * Two styles of listeners are supported:
+ * <ul>
+ * <li>Generic listener</li>
+ * <li>Dispatch listener - listener, which implements <code>{ModelName}Listener</code> interface,
+ * which has dispatch methods for each defined notification. Methods are invoked based on notification type (class).
+ * </li>
+ *
+ * <h3>Generic Listener</h3>
+ * <p>
+ * A generic listener implements the {@link NotificationListener} interface which has one callback method
+ * <code>onNotification</code> that is invoked for any notification type the listener is subscribed to.
+ * <p>
+ * A generic listener is subscribed using the {@link #registerNotificationListener(Class, NotificationListener)}
+ * method by which you specify the type of notification to receive. A generic listener may be registered for
+ * multiple notification types via multiple subscriptions.
+ * <p>
+ * Generic listeners allow for a more flexible approach, allowing you to subscribe for just
+ * one type of notification from a YANG model. You could also have a general subscription
+ * for all notification in the system via
+ * <pre>
+ *   service.registerNotificationListener(Notification.class, listener);
+ * </pre>
+ *
+ * <h3>Dispatch Listener</h3>
+ * <p>
+ * A dispatch listener implements a YANG-generated module interface <code>{ModuleName}Listener</code>
+ * which handles all the notifications defined in the YANG model. Each notification type translates to
+ * a specific method of the form <code>on{NotificationType}</code> on the generated interface.
+ * The generated interface also extends the
+ * {@link org.opendaylight.yangtools.yang.binding.NotificationListener} interface and implementations
+ * are registered using {@link #registerNotificationListener(org.opendaylight.yangtools.yang.binding.NotificationListener)}
+ * method.
+ *
+ * <h5>Dispatch Listener Example</h5>
+ * <p>
+ * Lets assume we have following YANG model:
+ *
+ * <pre>
+ * module example {
+ *      ...
+ *
+ *      notification start {
+ *          ...
+ *      }
+ *
+ *      notification stop {
+ *           ...
+ *      }
+ * }
+ * </pre>
+ *
+ * The generated interface will be:
+ * <pre>
+ *  public interface ExampleListener extends NotificationListener {
+ *      void onStart(Start notification);
+ *      void onStop(Stop notification);
+ *  }
+ * </pre>
+ * The following defines an implementation of the generated interface:
+ * <pre>
+ *  public class MyExampleListener implements ExampleListener {
+ *      public void onStart(Start notification) {
+ *          // do something
+ *      }
+ *
+ *      public void onStop(Stop notification) {
+ *          // do something
+ *      }
+ *  }
+ * </pre>
+ * The implementation is registered as follows:
+ * <pre>
+ *  MyExampleListener listener = new MyExampleListener();
+ *  ListenerRegistration<NotificationListener> reg = service.registerNotificationListener( listener );
+ * </pre>
+ * The <code>onStart</code> method will be invoked when someone publishes a <code>Start</code> notification and
+ * the <code>onStop</code> method will be invoked when someone publishes a <code>Stop</code> notification.
+ */
 public interface NotificationService extends BindingAwareService {
     /**
-     * Register a generic listener for specified notification type only.
+     * Registers a generic listener implementation for a specified notification type.
      *
-     * @param notificationType
-     * @param listener
-     * @return Registration for listener. To unregister listener invoke {@link ListenerRegistration#close()} method.
+     * @param notificationType the YANG-generated interface of the notification type.
+     * @param listener the listener implementation that will receive notifications.
+     * @return a {@link ListenerRegistration} instance that should be used to unregister the listener
+     *         by invoking the {@link ListenerRegistration#close()} method when no longer needed.
      */
     <T extends Notification> ListenerRegistration<NotificationListener<T>> registerNotificationListener(
             Class<T> notificationType, NotificationListener<T> listener);
 
     /**
-     * Register a listener which implements generated notification interfaces derived from
+     * Registers a listener which implements a YANG-generated notification interface derived from
      * {@link org.opendaylight.yangtools.yang.binding.NotificationListener}.
-     * Listener is registered for all notifications present in implemented interfaces.
+     * The listener is registered for all notifications present in the implemented interface.
      *
-     * @param listener
-     * @return Registration for listener. To unregister listener invoke {@link ListenerRegistration#close()} method.
+     * @param listener the listener implementation that will receive notifications.
+     * @return a {@link ListenerRegistration} instance that should be used to unregister the listener
+     *         by invoking the {@link ListenerRegistration#close()} method when no longer needed.
      */
     ListenerRegistration<org.opendaylight.yangtools.yang.binding.NotificationListener> registerNotificationListener(
             org.opendaylight.yangtools.yang.binding.NotificationListener listener);