fix: fixed error and debug messages

Signed-off-by: Matt Peterson <[email protected]>

server/src/main/java/com/hedera/block/server/consumer/ConsumerStreamResponseObserver.java

@@ -57,6 +57,9 @@ public class ConsumerStreamResponseObserver
     private final ResponseSender statusResponseSender = new StatusResponseSender();
     private final ResponseSender blockItemResponseSender = new BlockItemResponseSender();
 
+    private static final String PROTOCOL_VIOLATION_MESSAGE =
+            "Protocol Violation. %s is OneOf type %s but %s is null.\n%s";
+
     /**
      * The onCancel handler to execute when the consumer cancels the stream. This handler is
      * protected to facilitate testing.
@@ -153,7 +156,9 @@ public void onEvent(
             final long currentMillis = producerLivenessClock.millis();
             if (currentMillis - producerLivenessMillis > timeoutThresholdMillis) {
                 subscriptionHandler.unsubscribe(this);
-                LOGGER.log(DEBUG, "Unsubscribed ConsumerBlockItemObserver due to producer timeout");
+                LOGGER.log(
+                        DEBUG,
+                        "Producer liveness timeout. Unsubscribed ConsumerBlockItemObserver.");
             } else {
                 // Refresh the producer liveness and pass the BlockItem to the downstream observer.
                 producerLivenessMillis = currentMillis;
@@ -192,20 +197,21 @@ public void send(@NonNull final SubscribeStreamResponse subscribeStreamResponse)
             // the beginning of a block.
             final BlockItem blockItem = subscribeStreamResponse.blockItem();
             if (blockItem == null) {
-                LOGGER.log(
-                        ERROR,
-                        "SubscribeStreamResponse was of type BLOCK_ITEM but block_item is null."
-                                + " This is a protocol violation: {0}",
-                        subscribeStreamResponse.toString());
-                throw new IllegalArgumentException(
-                        "SubscribeStreamResponse was of type BlockItem but block_item is null");
+                final String message =
+                        PROTOCOL_VIOLATION_MESSAGE.formatted(
+                                "SubscribeStreamResponse",
+                                "BLOCK_ITEM",
+                                "block_item",
+                                subscribeStreamResponse);
+                LOGGER.log(ERROR, message);
+                throw new IllegalArgumentException(message);
             } else {
                 if (!streamStarted && blockItem.hasBlockHeader()) {
                     streamStarted = true;
                 }
 
                 if (streamStarted) {
-                    LOGGER.log(DEBUG, "Send BlockItem downstream: {0} ", blockItem);
+                    LOGGER.log(DEBUG, "Sending BlockItem downstream: {0}", blockItem);
                     subscribeStreamResponseObserver.onNext(
                             toProtocSubscribeStreamResponse(subscribeStreamResponse));
                 }
@@ -217,7 +223,7 @@ private final class StatusResponseSender implements ResponseSender {
         public void send(@NonNull final SubscribeStreamResponse subscribeStreamResponse) {
             LOGGER.log(
                     DEBUG,
-                    "Send SubscribeStreamResponse downstream: {0} ",
+                    "Sending SubscribeStreamResponse downstream: {0} ",
                     subscribeStreamResponse);
             subscribeStreamResponseObserver.onNext(
                     toProtocSubscribeStreamResponse(subscribeStreamResponse));