# Tracking a multipart upload with the AWS SDKs


You can track an object's upload progress to Amazon S3 with a listen interface. The high-level multipart upload API provides such a listen interface, called `ProgressListener`. Progress events occur periodically and notify the listener that bytes have been transferred. For more general information about multipart uploads, see [Uploading and copying objects using multipart upload in Amazon S3](mpuoverview.md).

For an end-to-end procedure on uploading an object with multipart upload with an additional checksum, see [Tutorial: Upload an object through multipart upload and verify its data integrity](tutorial-s3-mpu-additional-checksums.md).

The following section show how to track a multipart upload with the AWS SDKs.

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#### [ Java ]

**Example**  
The following Java code uploads a file and uses the `ExecutionInterceptor` to track the upload progress. For instructions on how to create and test a working sample, see [Getting Started](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html) in the AWS SDK for Java 2.x Developer Guide.   

```
import java.nio.file.Paths;

import software.amazon.awssdk.auth.credentials.ProfileCredentialsProvider;
import software.amazon.awssdk.core.async.AsyncRequestBody;
import software.amazon.awssdk.core.interceptor.Context;
import software.amazon.awssdk.core.interceptor.ExecutionAttributes;
import software.amazon.awssdk.core.interceptor.ExecutionInterceptor;
import software.amazon.awssdk.services.s3.S3AsyncClient;
import software.amazon.awssdk.services.s3.model.PutObjectRequest;

public class TrackMPUProgressUsingHighLevelAPI {

    static class ProgressListener implements ExecutionInterceptor {
        private long transferredBytes = 0;

        @Override
        public void beforeTransmission(Context.BeforeTransmission context, ExecutionAttributes executionAttributes) {
            if (context.httpRequest().firstMatchingHeader("Content-Length").isPresent()) {
                String contentLength = context.httpRequest().firstMatchingHeader("Content-Length").get();
                long partSize = Long.parseLong(contentLength);
                transferredBytes += partSize;
                System.out.println("Transferred bytes: " + transferredBytes);
            }
        }
    }

    public static void main(String[] args) throws Exception {
        String existingBucketName = "*** Provide bucket name ***";
        String keyName = "*** Provide object key ***";
        String filePath = "*** file to upload ***";

        S3AsyncClient s3Client = S3AsyncClient.builder()
                .credentialsProvider(ProfileCredentialsProvider.create())
                .overrideConfiguration(c -> c.addExecutionInterceptor(new ProgressListener()))
                .build();

        // For more advanced uploads, you can create a request object
        // and supply additional request parameters (ex: progress listeners,
        // canned ACLs, etc.)
        PutObjectRequest request = PutObjectRequest.builder()
                .bucket(existingBucketName)
                .key(keyName)
                .build();

        AsyncRequestBody requestBody = AsyncRequestBody.fromFile(Paths.get(filePath));

        // You can ask the upload for its progress, or you can
        // add a ProgressListener to your request to receive notifications
        // when bytes are transferred.
        // S3AsyncClient processes all transfers asynchronously,
        // so this call will return immediately.
        var upload = s3Client.putObject(request, requestBody);

        try {
            // You can block and wait for the upload to finish
            upload.join();
        } catch (Exception exception) {
            System.out.println("Unable to upload file, upload aborted.");
            exception.printStackTrace();
        } finally {
            s3Client.close();
        }
    }
}
```

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#### [ .NET ]

The following C\$1 example uploads a file to an S3 bucket using the `TransferUtility` class, and tracks the progress of the upload. For information about setting up and running the code examples, see [Getting Started with the AWS SDK for .NET](https://docs.aws.amazon.com/sdk-for-net/latest/developer-guide/net-dg-setup.html) in the *AWS SDK for .NET Developer Guide*. 

```
using Amazon;
using Amazon.S3;
using Amazon.S3.Transfer;
using System;
using System.Threading.Tasks;

namespace Amazon.DocSamples.S3
{
    class TrackMPUUsingHighLevelAPITest
    {
        private const string bucketName = "*** provide the bucket name ***";
        private const string keyName = "*** provide the name for the uploaded object ***";
        private const string filePath = " *** provide the full path name of the file to upload **";
        // Specify your bucket region (an example region is shown).
        private static readonly RegionEndpoint bucketRegion = RegionEndpoint.USWest2;
        private static IAmazonS3 s3Client;


        public static void Main()
        {
            s3Client = new AmazonS3Client(bucketRegion);
            TrackMPUAsync().Wait();
        }

        private static async Task TrackMPUAsync()
        {
            try
            {
                var fileTransferUtility = new TransferUtility(s3Client);

                // Use TransferUtilityUploadRequest to configure options.
                // In this example we subscribe to an event.
                var uploadRequest =
                    new TransferUtilityUploadRequest
                    {
                        BucketName = bucketName,
                        FilePath = filePath,
                        Key = keyName
                    };

                uploadRequest.UploadProgressEvent +=
                    new EventHandler<UploadProgressArgs>
                        (uploadRequest_UploadPartProgressEvent);

                await fileTransferUtility.UploadAsync(uploadRequest);
                Console.WriteLine("Upload completed");
            }
            catch (AmazonS3Exception e)
            {
                Console.WriteLine("Error encountered on server. Message:'{0}' when writing an object", e.Message);
            }
            catch (Exception e)
            {
                Console.WriteLine("Unknown encountered on server. Message:'{0}' when writing an object", e.Message);
            }
        }

        static void uploadRequest_UploadPartProgressEvent(object sender, UploadProgressArgs e)
        {
            // Process event.
            Console.WriteLine("{0}/{1}", e.TransferredBytes, e.TotalBytes);
        }
    }
}
```

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