Multipart download From S3 in Java

   public void multipartDownload(String accessKey, String secretKey, String region, String bucketName, String sourceFileName, String destinationFileName) throws Exception {

    try {
        // Create an S3 client using the provided access key, secret key, and region
        S3Client s3Client = getAWSS3Client(accessKey, secretKey, region);

        // List objects in the bucket with the specified prefix
        ListObjectsV2Response listObjectsV2Response = s3Client.listObjectsV2(b -> b.bucket(bucketName).prefix(sourceFileName));
        List<S3Object> objects = listObjectsV2Response.contents();
        Long size = objects.get(0).size();
        log.info("size of the file is {}", size);

        // Check if the file size is 0 and throw an exception if it is
        if (size == 0) {
            throw new FileNotFoundException("File is empty");
        }

        long partSize = 1024 * 1024 * 10; // Set the part size to 10 MB
        long contentLength = size;

        FileOutputStream fos = new FileOutputStream(destinationFileName);

        // Download the file in parts
        for (long start = 0; start < contentLength; start += partSize) {
            long end = Math.min(start + partSize - 1, contentLength - 1);
            GetObjectRequest rangeGetObjectRequest = GetObjectRequest.builder()
                    .bucket(bucketName)
                    .key(sourceFileName)
                    .range("bytes=" + start + "-" + end)
                    .build();

            ResponseInputStream<GetObjectResponse> responseInputStream = s3Client.getObject(rangeGetObjectRequest);

            byte[] buffer = new byte[1024 * 1024 * 10];
            int bytesRead;
            while ((bytesRead = responseInputStream.read(buffer)) != -1) {
                fos.write(buffer, 0, bytesRead);
            }
            responseInputStream.close();
        }
        fos.close();
    } catch (Exception e) {
        log.error("Exception Occurred while downloading files for key {} ", e.getMessage());
        throw new RuntimeException(e);
    }
}