unwrap throwable exception

Author: hu-ahmed

things/service/src/main/java/org/eclipse/ditto/things/service/persistence/actors/ThingPersistenceActor.java

@@ -15,6 +15,7 @@
 import java.time.Instant;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
 import java.util.concurrent.CompletionStage;
 
 import javax.annotation.Nullable;
@@ -24,6 +25,7 @@
 import org.apache.pekko.japi.pf.ReceiveBuilder;
 import org.apache.pekko.persistence.RecoveryCompleted;
 import org.eclipse.ditto.base.model.acks.DittoAcknowledgementLabel;
+import org.eclipse.ditto.base.model.exceptions.DittoInternalErrorException;
 import org.eclipse.ditto.base.model.exceptions.DittoRuntimeException;
 import org.eclipse.ditto.base.model.exceptions.DittoRuntimeExceptionBuilder;
 import org.eclipse.ditto.base.model.headers.DittoHeaders;
@@ -153,7 +155,7 @@ public void onStagedQuery(final Command<?> command, final CompletionStage<WithDi
             @Nullable final StartedSpan startedSpan) {
         final ActorRef sender = getSender();
         response.whenComplete((r, throwable) -> {
-            if (throwable instanceof DittoRuntimeException dittoRuntimeException) {
+            if (throwable != null && unwrapThrowable(throwable) instanceof DittoRuntimeException dittoRuntimeException) {
                 notifySender(sender, dittoRuntimeException);
             } else {
                 doOnQuery(command, r, sender);
@@ -164,6 +166,12 @@ public void onStagedQuery(final Command<?> command, final CompletionStage<WithDi
         });
     }
 
+    private static Throwable unwrapThrowable(final Throwable throwable) {
+        if (throwable instanceof CompletionException) {
+            return throwable.getCause() != null ? throwable.getCause() : throwable;
+        }
+        return throwable;
+    }
 
     private void doOnQuery(final Command<?> command, final WithDittoHeaders response, final ActorRef sender) {
         if (response.getDittoHeaders().didLiveChannelConditionMatch()) {