ACS-8832 Fix Event Outbox shutdown (#2959)

* ACS-8832 Add destroy method in EventSender

* ACS-8832 Rename

* ACS-8832 Reformat

repository/src/main/java/org/alfresco/repo/event2/EventGenerator.java

@@ -38,6 +38,12 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.context.ApplicationEvent;
+import org.springframework.extensions.surf.util.AbstractLifecycleBean;
+
 import org.alfresco.repo.domain.node.NodeDAO;
 import org.alfresco.repo.domain.node.TransactionEntity;
 import org.alfresco.repo.event.v1.model.DataAttributes;
@@ -81,11 +87,6 @@ import org.alfresco.service.transaction.TransactionService;
 import org.alfresco.util.PropertyCheck;
 import org.alfresco.util.TriPredicate;
 import org.alfresco.util.transaction.TransactionListenerAdapter;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-import org.springframework.beans.factory.InitializingBean;
-import org.springframework.context.ApplicationEvent;
-import org.springframework.extensions.surf.util.AbstractLifecycleBean;
 
 /**
  * Generates events and sends them to an event topic.
@@ -417,8 +418,7 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
     }
 
     /**
-     * @return the {@link NodeEventConsolidator} for the supplied {@code nodeRef} from
+     * @return the {@link NodeEventConsolidator} for the supplied {@code nodeRef} from the current transaction context.
-     * the current transaction context.
      */
     protected NodeEventConsolidator getEventConsolidator(NodeRef nodeRef)
     {
@@ -438,7 +438,6 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
         return eventConsolidator;
     }
 
-
     protected Consolidators getTxnConsolidators(Object resourceKey)
     {
         Consolidators consolidators = AlfrescoTransactionSupport.getResource(resourceKey);
@@ -451,8 +450,7 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
     }
 
     /**
-     * @return the {@link ChildAssociationEventConsolidator} for the supplied {@code childAssociationRef} from
+     * @return the {@link ChildAssociationEventConsolidator} for the supplied {@code childAssociationRef} from the current transaction context.
-     * the current transaction context.
      */
     private ChildAssociationEventConsolidator getEventConsolidator(ChildAssociationRef childAssociationRef)
     {
@@ -473,8 +471,7 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
     }
 
     /**
-     * @return the {@link PeerAssociationEventConsolidator} for the supplied {@code peerAssociationRef} from
+     * @return the {@link PeerAssociationEventConsolidator} for the supplied {@code peerAssociationRef} from the current transaction context.
-     * the current transaction context.
      */
     private PeerAssociationEventConsolidator getEventConsolidator(AssociationRef peerAssociationRef)
     {
@@ -528,8 +525,7 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
                 childAssociationRef.getQName(),
                 childAssociationRef.getChildRef(),
                 childAssociationRef.isPrimary(),
-            childAssociationRef.getNthSibling()
+                childAssociationRef.getNthSibling());
-        );
     }
 
     @Override
@@ -546,7 +542,10 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
     @Override
     protected void onShutdown(ApplicationEvent applicationEvent)
     {
-        //NOOP
+        if (eventSender != null)
+        {
+            eventSender.destroy();
+        }
     }
 
     protected class EventTransactionListener extends TransactionListenerAdapter
@@ -586,8 +585,7 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
         }
 
         /**
-         * @return true if a node transaction is not only active, but also committed with modifications.
+         * @return true if a node transaction is not only active, but also committed with modifications. This means that a {@link TransactionEntity} object was created.
-         * This means that a {@link TransactionEntity} object was created.
          */
         protected boolean isTransactionCommitted()
         {
@@ -601,7 +599,8 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
                 try
                 {
                     sendEvents();
-                } catch (Exception e)
+                }
+                catch (Exception e)
                 {
                     // Must consume the exception to protect other TransactionListeners
                     LOGGER.error("Unexpected error while sending repository events", e);
@@ -650,11 +649,16 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
         /**
          * Handles all kinds of events and sends them within dedicated transaction.
          *
-         * @param entityReference - reference to an entity (e.g. node, child association, peer association)
+         * @param entityReference
-         * @param eventConsolidator - object encapsulating events occurred in a transaction
+         *            - reference to an entity (e.g. node, child association, peer association)
-         * @param entityToEventEligibilityVerifier - allows to verify if entity is eligible to generate an even. If null no verification is necessary
+         * @param eventConsolidator
-         * @param <REF> - entity reference type (e.g. {@link NodeRef}, {@link AssociationRef}, {@link ChildAssociationRef})
+         *            - object encapsulating events occurred in a transaction
-         * @param <CON> - event consolidator type - extension of {@link EventConsolidator}
+         * @param entityToEventEligibilityVerifier
+         *            - allows to verify if entity is eligible to generate an even. If null no verification is necessary
+         * @param <REF>
+         *            - entity reference type (e.g. {@link NodeRef}, {@link AssociationRef}, {@link ChildAssociationRef})
+         * @param <CON>
+         *            - event consolidator type - extension of {@link EventConsolidator}
          */
         private <REF extends EntityRef, CON extends EventConsolidator<REF, ? extends Resource>> void sendEvent(
                 final REF entityReference, final CON eventConsolidator, final TriPredicate<REF, CON, EventInfo> entityToEventEligibilityVerifier)
@@ -676,12 +680,18 @@ public class EventGenerator extends AbstractLifecycleBean implements Initializin
         /**
          * Creates events from various kinds of entities.
          *
-         * @param entityReference - reference to an entity (e.g. node, child association, peer association)
+         * @param entityReference
-         * @param eventConsolidator - object encapsulating events occurred in a transaction
+         *            - reference to an entity (e.g. node, child association, peer association)
-         * @param eventInfo - object holding the event information
+         * @param eventConsolidator
-         * @param entityToEventEligibilityVerifier - allows to verify if entity is eligible to generate an even. If null no verification is necessary
+         *            - object encapsulating events occurred in a transaction
-         * @param <REF> - entity reference type (e.g. {@link NodeRef}, {@link AssociationRef}, {@link ChildAssociationRef})
+         * @param eventInfo
-         * @param <CON> - event consolidator type - extension of {@link EventConsolidator}
+         *            - object holding the event information
+         * @param entityToEventEligibilityVerifier
+         *            - allows to verify if entity is eligible to generate an even. If null no verification is necessary
+         * @param <REF>
+         *            - entity reference type (e.g. {@link NodeRef}, {@link AssociationRef}, {@link ChildAssociationRef})
+         * @param <CON>
+         *            - event consolidator type - extension of {@link EventConsolidator}
          */
         private <REF extends EntityRef, CON extends EventConsolidator<REF, ? extends Resource>> Optional<RepoEvent<?>> createEvent(
                 final REF entityReference, final CON eventConsolidator, final EventInfo eventInfo,

repository/src/main/java/org/alfresco/repo/event2/EventSender.java

@@ -37,19 +37,28 @@ public interface EventSender
 {
     /**
      * Accepts a callback function creating an event and sends this event to specified destination.
-     * @param eventProducer - callback function that creates an event
+     * 
+     * @param eventProducer
+     *            - callback function that creates an event
      */
     void accept(Callable<Optional<RepoEvent<?>>> eventProducer);
 
     /**
-     * It's called right after event sender instantiation (see {@link org.alfresco.repo.event2.EventSenderFactoryBean}).
+     * It's called right after event sender instantiation (see {@link org.alfresco.repo.event2.EventSenderFactoryBean}). It might be used to initialize the sender implementation.
-     * It might be used to initialize the sender implementation.
      */
     default void initialize()
     {
         // no initialization by default
     }
 
+    /**
+     * It's called when the application context is closing, allowing {@link org.alfresco.repo.event2.EventGenerator} to perform cleanup operations.
+     */
+    default void destroy()
+    {
+        // no destruction by default
+    }
+
     default boolean shouldParticipateInTransaction()
     {
         return false;