: For a large number of files, use a Java thread pool (e.g., ExecutorService ) to run getObject requests in parallel.

You can list objects in a bucket (optionally filtered by prefix) using the listObjectsV2 method. If there are more than 1,000 files, use the continuationToken to retrieve subsequent results. Step 2: Download Each File

For each object key found, use getObject to download the file content. You can write the stream directly to a file using ResponseTransformer.toFile() to avoid loading large files into memory.

The is the most efficient way to download multiple files or entire directories. It is built on top of the AWS CRT-based S3 client, which provides enhanced performance through automatic multipart downloads and byte-range fetches. Prerequisites Add the following dependency to your pom.xml :

import software.amazon.awssdk.transfer.s3.S3TransferManager; import software.amazon.awssdk.transfer.s3.model.DirectoryDownload; import software.amazon.awssdk.transfer.s3.model.DownloadDirectoryRequest; import java.nio.file.Paths; public class S3BulkDownload { public void downloadFolder(String bucketName, String s3Prefix, String localPath) { S3TransferManager transferManager = S3TransferManager.create(); DirectoryDownload directoryDownload = transferManager.downloadDirectory( DownloadDirectoryRequest.builder() .destinationDirectory(Paths.get(localPath)) .bucket(bucketName) .prefix(s3Prefix) .build() ); // Wait for the transfer to complete directoryDownload.completionFuture().join(); System.out.println("Download complete!"); } } Use code with caution. 2. Using S3 Client for Custom Logic

: Monitor for failed transfers using failedTransfers() if using Transfer Manager, and implement retry logic for network timeouts.

How To Download Multiple Files From S3 Bucket Using Java !!better!! Link

: For a large number of files, use a Java thread pool (e.g., ExecutorService ) to run getObject requests in parallel.

For each object key found, use getObject to download the file content. You can write the stream directly to a file using ResponseTransformer.toFile() to avoid loading large files into memory. : For a large number of files, use a Java thread pool (e

: Monitor for failed transfers using failedTransfers() if using Transfer Manager, and implement retry logic for network timeouts.