Add a warning to note that checksumValidationEnabled is true by default.

Author: Quanzzzz

services/s3/src/main/java/software/amazon/awssdk/services/s3/internal/presigner/DefaultS3Presigner.java

@@ -90,17 +90,20 @@
 import software.amazon.awssdk.services.s3.transform.PutObjectRequestMarshaller;
 import software.amazon.awssdk.services.s3.transform.UploadPartRequestMarshaller;
 import software.amazon.awssdk.utils.IoUtils;
+import software.amazon.awssdk.utils.Logger;
 import software.amazon.awssdk.utils.Validate;
 
 /**
  * The default implementation of the {@link S3Presigner} interface.
  */
 @SdkInternalApi
 public final class DefaultS3Presigner extends DefaultSdkPresigner implements S3Presigner {
+    private static final Logger log = Logger.loggerFor(DefaultS3Presigner.class);
+
     private static final AwsS3V4Signer DEFAULT_SIGNER = AwsS3V4Signer.create();
     private static final S3Configuration DEFAULT_S3_CONFIGURATION = S3Configuration.builder()
-            .checksumValidationEnabled(false)
-            .build();
+                                                                                   .checksumValidationEnabled(false)
+                                                                                   .build();
     private static final String SERVICE_NAME = "s3";
     private static final String SIGNING_NAME = "s3";
 
@@ -117,6 +120,11 @@ private DefaultS3Presigner(Builder b) {
         super(b);
 
         this.serviceConfiguration = b.serviceConfiguration != null ? b.serviceConfiguration : DEFAULT_S3_CONFIGURATION;
+        if (serviceConfiguration.checksumValidationEnabled()) {
+            log.debug(() -> "The provided S3Configuration has ChecksumValidationEnabled set to true. Please note that "
+                           + "the pre-signed request can't be executed using a web browser if checksum validation is enabled.");
+        }
+
 
         this.clientInterceptors = initializeInterceptors();