feedback addressed

Author: Fred1155

.changes/next-release/bugfix-AWSSDKforJavav2-17f90b1.json

@@ -0,0 +1,6 @@
+{
+    "type": "bugfix",
+    "category": "Amazon S3",
+    "contributor": "",
+    "description": "Added additional validations for multipart download operations in the Java multipart S3 client"
+}

.changes/next-release/bugfix-AmazonS3-34da391.json

@@ -114,12 +114,13 @@ public void onNext(AsyncResponseTransformer<GetObjectResponse, GetObjectResponse
             throw new NullPointerException("onNext must not be called with null asyncResponseTransformer");
         }
 
-        int nextPartToGet = completedParts.get() + 1;
+        int currentPart = completedParts.get();
+        int nextPartToGet =  currentPart + 1;
 
         synchronized (lock) {
             if (totalParts != null && nextPartToGet > totalParts) {
-                validatePartsCount(completedParts.get());
                 log.debug(() -> String.format("Completing multipart download after a total of %d parts downloaded.", totalParts));
+                validatePartsCount(currentPart);
                 subscription.cancel();
                 return;
             }
@@ -168,7 +169,7 @@ private void requestMoreIfNeeded(GetObjectResponse response) {
             if (totalParts != null && totalParts > 1 && totalComplete < totalParts) {
                 subscription.request(1);
             } else {
-                validatePartsCount(completedParts.get());
+                validatePartsCount(totalComplete);
                 log.debug(() -> String.format("Completing multipart download after a total of %d parts downloaded.", totalParts));
                 subscription.cancel();
             }
@@ -204,9 +205,8 @@ private GetObjectRequest nextRequest(int nextPartToGet) {
 
     private void validatePartsCount(int currentGetCount) {
         if (totalParts != null && currentGetCount != totalParts) {
-            String errorMessage = "PartsCount validation failed. Expected " + totalParts + ", downloaded"
-                                  + " " + currentGetCount + " parts.";
-            log.error(() -> errorMessage);
+            String errorMessage = String.format("PartsCount validation failed. Expected %d, downloaded %d parts.", totalParts,
+                                                 currentGetCount);
             subscription.cancel();
             SdkClientException exception = SdkClientException.create(errorMessage);
             onError(exception);

services/s3/src/main/java/software/amazon/awssdk/services/s3/internal/multipart/MultipartDownloaderSubscriber.java

@@ -36,7 +36,6 @@
 import software.amazon.awssdk.core.sync.ResponseTransformer;
 import software.amazon.awssdk.metrics.publishers.emf.EmfMetricLoggingPublisher;
 import software.amazon.awssdk.metrics.publishers.emf.internal.MetricEmfConverter;
-import software.amazon.awssdk.services.s3.internal.multipart.MultipartDownloaderSubscriber;
 import software.amazon.awssdk.utils.Logger;
 
 /**
@@ -58,7 +57,6 @@ public class CodingConventionWithSuppressionTest {
     private static final Set<Pattern> ALLOWED_ERROR_LOG_SUPPRESSION = new HashSet<>(
         Arrays.asList(
             ArchUtils.classNameToPattern(EmfMetricLoggingPublisher.class),
-            ArchUtils.classNameToPattern(MultipartDownloaderSubscriber.class),
             ArchUtils.classWithInnerClassesToPattern(ResponseTransformer.class)));
 
     @Test