refactor so that any java 8 or later can use lambdas for Activate and… (#175)

* refactor so that any java 8 or later can use lambdas for Activate and Track listeners.

* make some updates according to mike's comments

* add some unit tests to up code coverage

Author: thomaszurkan-optimizely

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -39,7 +39,6 @@
 import com.optimizely.ab.event.internal.EventBuilder;
 import com.optimizely.ab.event.internal.payload.EventBatch.ClientEngine;
 import com.optimizely.ab.internal.EventTagUtils;
-import com.optimizely.ab.notification.NotificationBroadcaster;
 import com.optimizely.ab.notification.NotificationCenter;
 import com.optimizely.ab.notification.NotificationListener;
 import org.slf4j.Logger;
@@ -90,7 +89,6 @@ public class Optimizely {
     @VisibleForTesting final ProjectConfig projectConfig;
     @VisibleForTesting final EventHandler eventHandler;
     @VisibleForTesting final ErrorHandler errorHandler;
-    @VisibleForTesting final NotificationBroadcaster notificationBroadcaster = new NotificationBroadcaster();
     public final NotificationCenter notificationCenter = new NotificationCenter();
 
     @Nullable private final UserProfileService userProfileService;
@@ -205,8 +203,6 @@ private void sendImpression(@Nonnull ProjectConfig projectConfig,
                 logger.error("Unexpected exception in event dispatcher", e);
             }
 
-            notificationBroadcaster.broadcastExperimentActivated(experiment, userId, filteredAttributes, variation);
-
             notificationCenter.sendNotifications(NotificationCenter.NotificationType.Activate, experiment, userId,
                     filteredAttributes, variation, impressionEvent);
         } else {
@@ -245,12 +241,9 @@ public void track(@Nonnull String eventName,
         // attributes.
         Map<String, String> filteredAttributes = filterAttributes(currentConfig, attributes);
 
-        Long eventValue = null;
         if (eventTags == null) {
             logger.warn("Event tags is null when non-null was expected. Defaulting to an empty event tags map.");
             eventTags = Collections.<String, String>emptyMap();
-        } else {
-            eventValue = EventTagUtils.getRevenueValue(eventTags);
         }
 
         List<Experiment> experimentsForEvent = projectConfig.getExperimentsForEventKey(eventName);
@@ -293,8 +286,6 @@ public void track(@Nonnull String eventName,
             logger.error("Unexpected exception in event dispatcher", e);
         }
 
-        notificationBroadcaster.broadcastEventTracked(eventName, userId, filteredAttributes, eventValue,
-                conversionEvent);
         notificationCenter.sendNotifications(NotificationCenter.NotificationType.Track, eventName, userId,
                 filteredAttributes, eventTags, conversionEvent);
     }
@@ -729,36 +720,6 @@ public UserProfileService getUserProfileService() {
         return userProfileService;
     }
 
-    //======== Notification listeners ========//
-
-    /**
-     * Add a {@link NotificationListener} if it does not exist already.
-     *
-     * @param listener listener to add
-     */
-    @Deprecated
-    public void addNotificationListener(@Nonnull NotificationListener listener) {
-        notificationBroadcaster.addListener(listener);
-    }
-
-    /**
-     * Remove a {@link NotificationListener} if it exists.
-     *
-     * @param listener listener to remove
-     */
-    @Deprecated
-    public void removeNotificationListener(@Nonnull NotificationListener listener) {
-        notificationBroadcaster.removeListener(listener);
-    }
-
-    /**
-     * Remove all {@link NotificationListener}.
-     */
-    @Deprecated
-    public void clearNotificationListeners() {
-        notificationBroadcaster.clearListeners();
-    }
-
     //======== Helper methods ========//
 
     /**

core-api/src/main/java/com/optimizely/ab/notification/ActivateNotificationListener.java

@@ -25,7 +25,7 @@
 import java.util.Map;
 
 
-public abstract class ActivateNotificationListener extends NotificationListener {
+public abstract class ActivateNotificationListener implements NotificationListener, ActivateNotificationListenerInterface {
 
     /**
      * Base notify called with var args.  This method parses the parameters and calls the abstract method.

core-api/src/main/java/com/optimizely/ab/notification/ActivateNotificationListenerInterface.java

@@ -0,0 +1,25 @@
+package com.optimizely.ab.notification;
+
+import com.optimizely.ab.config.Experiment;
+import com.optimizely.ab.config.Variation;
+import com.optimizely.ab.event.LogEvent;
+
+import javax.annotation.Nonnull;
+import java.util.Map;
+
+public interface ActivateNotificationListenerInterface {
+    /**
+     * onActivate called when an activate was triggered
+     * @param experiment - The experiment object being activated.
+     * @param userId - The userId passed into activate.
+     * @param attributes - The filtered attribute list passed into activate
+     * @param variation - The variation that was returned from activate.
+     * @param event - The impression event that was triggered.
+     */
+    public void onActivate(@Nonnull Experiment experiment,
+                                    @Nonnull String userId,
+                                    @Nonnull Map<String, String> attributes,
+                                    @Nonnull Variation variation,
+                                    @Nonnull LogEvent event) ;
+
+}

core-api/src/main/java/com/optimizely/ab/notification/NotificationBroadcaster.java

@@ -1,6 +1,6 @@
 /**
  *
- *    Copyright 2017, Optimizely and contributors
+ *    Copyright 2017-2018, Optimizely and contributors
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -16,9 +16,13 @@
  */
 package com.optimizely.ab.notification;
 
+import com.optimizely.ab.config.Experiment;
+import com.optimizely.ab.config.Variation;
+import com.optimizely.ab.event.LogEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nonnull;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;
@@ -78,6 +82,43 @@ public NotificationCenter() {
     // we used a list so that notification order can mean something.
     private Map<NotificationType, ArrayList<NotificationHolder>> notificationsListeners =new HashMap<NotificationType, ArrayList<NotificationHolder>>();
 
+    /**
+     * Convenience method to support lambdas as callbacks in later version of Java (8+).
+     * @param activateNotificationListenerInterface
+     * @return greater than zero if added.
+     */
+    public int addActivateNotificationListener(final ActivateNotificationListenerInterface activateNotificationListenerInterface) {
+        if (activateNotificationListenerInterface instanceof ActivateNotificationListener) {
+            return addNotificationListener(NotificationType.Activate, (NotificationListener)activateNotificationListenerInterface);
+        }
+        else {
+            return addNotificationListener(NotificationType.Activate, new ActivateNotificationListener() {
+                @Override
+                public void onActivate(@Nonnull Experiment experiment, @Nonnull String userId, @Nonnull Map<String, String> attributes, @Nonnull Variation variation, @Nonnull LogEvent event) {
+                    activateNotificationListenerInterface.onActivate(experiment, userId, attributes, variation, event);
+                }
+            });
+        }
+    }
+
+    /**
+     * Convenience method to support lambdas as callbacks in later versions of Java (8+)
+     * @param trackNotificationListenerInterface
+     * @return greater than zero if added.
+     */
+    public int addTrackNotificationListener(final TrackNotificationListenerInterface trackNotificationListenerInterface) {
+        if (trackNotificationListenerInterface instanceof TrackNotificationListener) {
+            return addNotificationListener(NotificationType.Activate, (NotificationListener)trackNotificationListenerInterface);
+        }
+        else {
+            return addNotificationListener(NotificationType.Track, new TrackNotificationListener() {
+                @Override
+                public void onTrack(@Nonnull String eventKey, @Nonnull String userId, @Nonnull Map<String, String> attributes, @Nonnull Map<String, ?> eventTags, @Nonnull LogEvent event) {
+                    trackNotificationListenerInterface.onTrack(eventKey, userId, attributes, eventTags, event);
+                }
+            });
+        }
+    }
 
     /**
      * Add a notification listener to the notification center.
@@ -86,7 +127,7 @@ public NotificationCenter() {
      * @param notificationListener - Notification to add.
      * @return the notification id used to remove the notification.  It is greater than 0 on success.
      */
-    public int addNotification(NotificationType notificationType, NotificationListener notificationListener) {
+    public int addNotificationListener(NotificationType notificationType, NotificationListener notificationListener) {
 
         Class clazz = notificationType.notificationTypeClass;
         if (clazz == null || !clazz.isInstance(notificationListener)) {
@@ -107,11 +148,11 @@ public int addNotification(NotificationType notificationType, NotificationListen
     }
 
     /**
-     * Remove the notification listener based on the notificationId passed back from addNotification.
+     * Remove the notification listener based on the notificationId passed back from addNotificationListener.
      * @param notificationID the id passed back from add notification.
      * @return true if removed otherwise false (if the notification is already registered, it returns false).
      */
-   public boolean removeNotification(int notificationID) {
+   public boolean removeNotificationListener(int notificationID) {
        for (NotificationType type : NotificationType.values()) {
             for (NotificationHolder holder : notificationsListeners.get(type)) {
                 if (holder.notificationId == notificationID) {
@@ -130,17 +171,17 @@ public boolean removeNotification(int notificationID) {
     /**
      * Clear out all the notification listeners.
      */
-    public void clearAllNotifications() {
+    public void clearAllNotificationListeners() {
         for (NotificationType type : NotificationType.values()) {
-            clearNotifications(type);
+            clearNotificationListeners(type);
         }
     }
 
     /**
      * Clear notification listeners by notification type.
      * @param notificationType type of notificationsListeners to remove.
      */
-    public void clearNotifications(NotificationType notificationType) {
+    public void clearNotificationListeners(NotificationType notificationType) {
         notificationsListeners.get(notificationType).clear();
     }