Add sequence number to Actors

When actors with duplicate names are loaded, a way is needed to
determine which should take precedence. Added a sequence number to
Actor to facilitate this.  Unfortunately, couldn't use OrderedServiceImpl,
because it only creates the Actors once, which would break a number
of junit tests.

Issue-ID: POLICY-1625
Signed-off-by: Jim Hahn <jrh3@att.com>
Change-Id: I1ade92f4fe516cfc54bb92d0a3624c67e8981075

3 files changed, 49 insertions, 12 deletions

diff --git a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/ActorService.java b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/ActorService.java
index b0d70fda0..49379b28c 100644
--- a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/ActorService.java
+++ b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/ActorService.java
@@ -25,6 +25,8 @@ import com.google.common.collect.ImmutableMap;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
 import java.util.Map;
 import java.util.ServiceConfigurationError;
 import java.util.ServiceLoader;
@@ -55,17 +57,7 @@ public class ActorService extends StartConfigPartial<Map<String, Object>> {
 
         Map<String, Actor> map = new HashMap<>();
 
-        Iterator<Actor> iter = loadActors().iterator();
-        while (iter.hasNext()) {
-
-            Actor newActor;
-            try {
-                newActor = iter.next();
-            } catch (ServiceConfigurationError e) {
-                logger.warn("unable to load actor", e);
-                continue;
-            }
-
+        for (Actor newActor : buildList()) {
             map.compute(newActor.getName(), (name, existingActor) -> {
                 if (existingActor == null) {
                     return newActor;
@@ -81,6 +73,35 @@ public class ActorService extends StartConfigPartial<Map<String, Object>> {
     }
 
     /**
+     * Builds the list of actors, discarding those that cannot be constructed.
+     *
+     * @return the list of actors, sorted by ascending sequence number
+     */
+    private List<Actor> buildList() {
+        List<Actor> actors = new LinkedList<>();
+
+        Iterator<Actor> iter = loadActors().iterator();
+        while (iter.hasNext()) {
+            try {
+                actors.add(iter.next());
+            } catch (ServiceConfigurationError e) {
+                logger.warn("unable to load actor", e);
+            }
+        }
+
+        actors.sort((actor1, actor2) -> {
+            int cmp = Integer.compare(actor1.getSequenceNumber(), actor2.getSequenceNumber());
+            if (cmp != 0) {
+                return cmp;
+            }
+
+            return actor1.getClass().getName().compareTo(actor2.getClass().getName());
+        });
+
+        return actors;
+    }
+
+    /**
      * Gets a particular actor.
      *
      * @param name name of the actor of interest
diff --git a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/impl/ActorImpl.java b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/impl/ActorImpl.java
index 0c88ebee2..12af030d5 100644
--- a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/impl/ActorImpl.java
+++ b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/impl/ActorImpl.java
@@ -56,6 +56,14 @@ public class ActorImpl extends StartConfigPartial<Map<String, Object>> implement
     }
 
     /**
+     * This method simply returns {@code 0}.
+     */
+    @Override
+    public int getSequenceNumber() {
+        return 0;
+    }
+
+    /**
      * Adds an operator supported by this actor.
      *
      * @param operator operation to be added
diff --git a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/spi/Actor.java b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/spi/Actor.java
index 53bee5f00..52d1a5a9a 100644
--- a/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/spi/Actor.java
+++ b/models-interactions/model-actors/actorServiceProvider/src/main/java/org/onap/policy/controlloop/actorserviceprovider/spi/Actor.java
@@ -36,7 +36,7 @@ import org.onap.policy.controlloop.actorserviceprovider.Operator;
  * @author pameladragosh
  *
  */
-public interface Actor extends Startable, Configurable<Map<String,Object>> {
+public interface Actor extends Startable, Configurable<Map<String, Object>> {
 
     /**
      * Gets the name of the actor.
@@ -68,6 +68,14 @@ public interface Actor extends Startable, Configurable<Map<String,Object>> {
      */
     public Set<String> getOperationNames();
 
+    /**
+     * Gets the actor sequence number. Lower numbered actors take precedence over higher
+     * numbered actors.
+     *
+     * @return the actor sequence number
+     */
+    public int getSequenceNumber();
+
 
     // TODO old code: remove lines down to **HERE**