AWS SDK Version 4 for .NET
API Reference

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Container for the parameters to the CompleteMultipartUpload operation. Completes a multipart upload by assembling previously uploaded parts.

You first initiate the multipart upload and then upload all parts using the UploadPart operation or the UploadPartCopy operation. After successfully uploading all relevant parts of an upload, you call this CompleteMultipartUpload operation to complete the upload. Upon receiving this request, Amazon S3 concatenates all the parts in ascending order by part number to create a new object. In the CompleteMultipartUpload request, you must provide the parts list and ensure that the parts list is complete. The CompleteMultipartUpload API operation concatenates the parts that you provide in the list. For each part in the list, you must provide the PartNumber value and the ETag value that are returned after that part was uploaded.

The processing of a CompleteMultipartUpload request could take several minutes to finalize. After Amazon S3 begins processing the request, it sends an HTTP response header that specifies a 200 OK response. While processing is in progress, Amazon S3 periodically sends white space characters to keep the connection from timing out. A request could fail after the initial 200 OK response has been sent. This means that a 200 OK response can contain either a success or an error. The error response might be embedded in the 200 OK response. If you call this API operation directly, make sure to design your application to parse the contents of the response and handle it appropriately. If you use Amazon Web Services SDKs, SDKs handle this condition. The SDKs detect the embedded error and apply error handling per your configuration settings (including automatically retrying the request as appropriate). If the condition persists, the SDKs throw an exception (or, for the SDKs that don't use exceptions, they return an error).

Note that if CompleteMultipartUpload fails, applications should be prepared to retry any failed requests (including 500 error responses). For more information, see Amazon S3 Error Best Practices.

You can't use Content-Type: application/x-www-form-urlencoded for the CompleteMultipartUpload requests. Also, if you don't provide a Content-Type header, CompleteMultipartUpload can still return a 200 OK response.

For more information about multipart uploads, see Uploading Objects Using Multipart Upload in the Amazon S3 User Guide.

Directory buckets - For directory buckets, you must make requests for this API operation to the Zonal endpoint. These endpoints support virtual-hosted-style requests in the format https://amzn-s3-demo-bucket.s3express-zone-id.region-code.amazonaws.com/key-name. Path-style requests are not supported. For more information about endpoints in Availability Zones, see Regional and Zonal endpoints for directory buckets in Availability Zones in the Amazon S3 User Guide. For more information about endpoints in Local Zones, see Concepts for directory buckets in Local Zones in the Amazon S3 User Guide.

Permissions

  • General purpose bucket permissions - For information about permissions required to use the multipart upload API, see Multipart Upload and Permissions in the Amazon S3 User Guide.

    If you provide an additional checksum value in your MultipartUpload requests and the object is encrypted with Key Management Service, you must have permission to use the kms:Decrypt action for the CompleteMultipartUpload request to succeed.

  • Directory bucket permissions - To grant access to this API operation on a directory bucket, we recommend that you use the CreateSession API operation for session-based authorization. Specifically, you grant the s3express:CreateSession permission to the directory bucket in a bucket policy or an IAM identity-based policy. Then, you make the CreateSession API call on the bucket to obtain a session token. With the session token in your request header, you can make API requests to this operation. After the session token expires, you make another CreateSession API call to generate a new session token for use. Amazon Web Services CLI or SDKs create session and refresh the session token automatically to avoid service interruptions when a session expires. For more information about authorization, see CreateSession.

    If the object is encrypted with SSE-KMS, you must also have the kms:GenerateDataKey and kms:Decrypt permissions in IAM identity-based policies and KMS key policies for the KMS key.

Special errors

  • Error Code: EntityTooSmall

    • Description: Your proposed upload is smaller than the minimum allowed object size. Each part must be at least 5 MB in size, except the last part.

    • HTTP Status Code: 400 Bad Request

  • Error Code: InvalidPart

    • Description: One or more of the specified parts could not be found. The part might not have been uploaded, or the specified ETag might not have matched the uploaded part's ETag.

    • HTTP Status Code: 400 Bad Request

  • Error Code: InvalidPartOrder

    • Description: The list of parts was not in ascending order. The parts list must be specified in order by part number.

    • HTTP Status Code: 400 Bad Request

  • Error Code: NoSuchUpload

    • Description: The specified multipart upload does not exist. The upload ID might be invalid, or the multipart upload might have been aborted or completed.

    • HTTP Status Code: 404 Not Found

HTTP Host header syntax

Directory buckets - The HTTP Host header syntax is Bucket-name.s3express-zone-id.region-code.amazonaws.com.

The following operations are related to CompleteMultipartUpload:

You must URL encode any signed header values that contain spaces. For example, if your header value is my file.txt, containing two spaces after my, you must URL encode this value to my%20%20file.txt.

Inheritance Hierarchy

System.Object
  Amazon.Runtime.AmazonWebServiceRequest
    Amazon.S3.Model.CompleteMultipartUploadRequest

Namespace: Amazon.S3.Model
Assembly: AWSSDK.S3.dll
Version: 3.x.y.z

Syntax

C# 
public class CompleteMultipartUploadRequest : AmazonWebServiceRequest
         IAmazonWebServiceRequest

The CompleteMultipartUploadRequest type exposes the following members

Constructors

NameDescription
Public Method CompleteMultipartUploadRequest()

Properties

NameTypeDescription
Public Property BucketName System.String

Gets and sets the property BucketName.

Name of the bucket to which the multipart upload was initiated.

Directory buckets - When you use this operation with a directory bucket, you must use virtual-hosted-style requests in the format Bucket-name.s3express-zone-id.region-code.amazonaws.com. Path-style requests are not supported. Directory bucket names must be unique in the chosen Zone (Availability Zone or Local Zone). Bucket names must follow the format bucket-base-name--zone-id--x-s3 (for example, amzn-s3-demo-bucket--usw2-az1--x-s3). For information about bucket naming restrictions, see Directory bucket naming rules in the Amazon S3 User Guide.

Access points - When you use this action with an access point for general purpose buckets, you must provide the alias of the access point in place of the bucket name or specify the access point ARN. When you use this action with an access point for directory buckets, you must provide the access point name in place of the bucket name. When using the access point ARN, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this action with an access point through the Amazon Web Services SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using access points in the Amazon S3 User Guide.

Object Lambda access points are not supported by directory buckets.

S3 on Outposts - When you use this action with S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When you use this action with S3 on Outposts, the destination bucket must be the Outposts access point ARN or the access point alias. For more information about S3 on Outposts, see What is S3 on Outposts? in the Amazon S3 User Guide.

Public Property ChecksumCRC32 System.String

Gets and sets the property ChecksumCRC32.

This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the Base64 encoded, 32-bit CRC32 checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ChecksumCRC32C System.String

Gets and sets the property ChecksumCRC32C.

This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the Base64 encoded, 32-bit CRC32C checksum of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ChecksumCRC64NVME System.String

Gets and sets the property ChecksumCRC64NVME.

This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the Base64 encoded, 64-bit CRC64NVME checksum of the object. The CRC64NVME checksum is always a full object checksum. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ChecksumSHA1 System.String

Gets and sets the property ChecksumSHA1.

This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the Base64 encoded, 160-bit SHA1 digest of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ChecksumSHA256 System.String

Gets and sets the property ChecksumSHA256.

This header can be used as a data integrity check to verify that the data received is the same data that was originally sent. This header specifies the Base64 encoded, 256-bit SHA256 digest of the object. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ChecksumType Amazon.S3.ChecksumType

Gets and sets the property ChecksumType.

This header specifies the checksum type of the object, which determines how part-level checksums are combined to create an object-level checksum for multipart objects. You can use this header as a data integrity check to verify that the checksum type that is received is the same checksum that was specified. If the checksum type doesn’t match the checksum type that was specified for the object during the CreateMultipartUpload request, it’ll result in a BadDigest error. For more information, see Checking object integrity in the Amazon S3 User Guide.

Public Property ExpectedBucketOwner System.String

Gets and sets the property ExpectedBucketOwner.

The account ID of the expected bucket owner. If the account ID that you provide does not match the actual owner of the bucket, the request fails with the HTTP status code 403 Forbidden (access denied).

Public Property IfMatch System.String

Gets and sets the property IfMatch.

Uploads the object only if the ETag (entity tag) value provided during the WRITE operation matches the ETag of the object in S3. If the ETag values do not match, the operation returns a 412 Precondition Failed error.

If a conflicting operation occurs during the upload S3 returns a 409 ConditionalRequestConflict response. On a 409 failure you should fetch the object's ETag, re-initiate the multipart upload with CreateMultipartUpload, and re-upload each part.

Expects the ETag value as a string.

For more information about conditional requests, see RFC 7232, or Conditional requests in the Amazon S3 User Guide.

Public Property IfNoneMatch System.String

Gets and sets the property IfNoneMatch.

Uploads the object only if the object key name does not already exist in the bucket specified. Otherwise, Amazon S3 returns a 412 Precondition Failed error.

If a conflicting operation occurs during the upload S3 returns a 409 ConditionalRequestConflict response. On a 409 failure you should re-initiate the multipart upload with CreateMultipartUpload and re-upload each part.

Expects the '*' (asterisk) character.

For more information about conditional requests, see RFC 7232, or Conditional requests in the Amazon S3 User Guide.

Public Property Key System.String

Gets and sets the property Key.

Object key for which the multipart upload was initiated.

Public Property MpuObjectSize System.Nullable<System.Int64>

Gets and sets the property MpuObjectSize.

The expected total object size of the multipart upload request. If there’s a mismatch between the specified object size value and the actual object size value, it results in an HTTP 400 InvalidRequest error.

Public Property PartETags System.Collections.Generic.List<Amazon.S3.Model.PartETag>

Gets and sets the property PartETags.

Array of CompletedPart data types.

If you do not supply a valid Part with your request, the service sends back an HTTP 400 response.

Starting with version 4 of the SDK this property will default to null. If no data for this property is returned from the service the property will also be null. This was changed to improve performance and allow the SDK and caller to distinguish between a property not set or a property being empty to clear out a value. To retain the previous SDK behavior set the AWSConfigs.InitializeCollections static property to true.

Public Property RequestPayer Amazon.S3.RequestPayer

Gets and sets the property RequestPayer.

Public Property SSECustomerAlgorithm System.String

Gets and sets the property SSECustomerAlgorithm.

The server-side encryption (SSE) algorithm used to encrypt the object. This parameter is required only when the object was created using a checksum algorithm or if your bucket policy requires the use of SSE-C. For more information, see Protecting data using SSE-C keys in the Amazon S3 User Guide.

This functionality is not supported for directory buckets.

Public Property SSECustomerKey System.String

Gets and sets the property SSECustomerKey.

The server-side encryption (SSE) customer managed key. This parameter is needed only when the object was created using a checksum algorithm. For more information, see Protecting data using SSE-C keys in the Amazon S3 User Guide.

This functionality is not supported for directory buckets.

Public Property SSECustomerKeyMD5 System.String

Gets and sets the property SSECustomerKeyMD5.

The MD5 server-side encryption (SSE) customer managed key. This parameter is needed only when the object was created using a checksum algorithm. For more information, see Protecting data using SSE-C keys in the Amazon S3 User Guide.

This functionality is not supported for directory buckets.

Public Property UploadId System.String

Gets and sets the property UploadId.

ID for the initiated multipart upload.

Methods

Note:

Asynchronous operations (methods ending with Async) in the table below are for .NET 4.7.2 or higher.

NameDescription
Public Method AddPartETags(PartETag[])

Adds a collection of parts (including ETags and checksums) to this request.

Public Method AddPartETags(IEnumerable<PartETag>)

Adds a collection of parts (including ETags and checksums) to this request.

Public Method AddPartETags(UploadPartResponse[])

Adds a collection of part numbers and corresponding etags by transforming the UploadPartResponses into PartETags.

Public Method AddPartETags(IEnumerable<UploadPartResponse>)

Adds a collection of part numbers and corresponding etags by transforming the UploadPartResponses into PartETags.

Public Method AddPartETags(CopyPartResponse[])

Adds a collection of part numbers and corresponding etags by transforming the CopyPartResponse into PartETags.

Public Method AddPartETags(IEnumerable<CopyPartResponse>)

Adds a collection of part numbers and corresponding etags by transforming the CopyPartResponse into PartETags.

Public Method AddPartETagsAndChecksums(UploadPartResponse[])

Adds a collection of part numbers, ETags and checksums by transforming the UploadPartResponses into PartETags.

Public Method AddPartETagsAndChecksums(IEnumerable<UploadPartResponse>)

Adds a collection of part numbers, ETags and checksums by transforming the UploadPartResponses into PartETags.

Public Method AddPartETagsAndChecksums(CopyPartResponse[])

Adds a collection of part numbers, ETags and checksums by transforming the UploadPartResponses into PartETags.

Public Method AddPartETagsAndChecksums(IEnumerable<CopyPartResponse>)

Adds a collection of part numbers, ETags and checksums by transforming the UploadPartResponses into PartETags.

Examples

This example shows how to upload 13MB of data using mutlipart upload.
The data is contained in a stream and the upload is done in 3 parts: 5MB, 5MB, then the remainder.

Multipart Upload Sample


int MB = (int)Math.Pow(2, 20);

// Create a client
AmazonS3Client client = new AmazonS3Client();

// Define input stream
Stream inputStream = Create13MBDataStream();

// Initiate multipart upload
InitiateMultipartUploadRequest initRequest = new InitiateMultipartUploadRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1"
};
InitiateMultipartUploadResponse initResponse = await client.InitiateMultipartUploadAsync(initRequest);

// Upload part 1
UploadPartRequest uploadRequest = new UploadPartRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 1,
    PartSize = 5 * MB,
    InputStream = inputStream
};
UploadPartResponse up1Response = await client.UploadPartAsync(uploadRequest);

// Upload part 2
uploadRequest = new UploadPartRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 2,
    PartSize = 5 * MB,
    InputStream = inputStream
};
UploadPartResponse up2Response = await client.UploadPartAsync(uploadRequest);

// Upload part 3
uploadRequest = new UploadPartRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartNumber = 3,
    InputStream = inputStream
};
UploadPartResponse up3Response = await client.UploadPartAsync(uploadRequest);

// List parts for current upload
ListPartsRequest listPartRequest = new ListPartsRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1",
    UploadId = initResponse.UploadId
};
ListPartsResponse listPartResponse = await client.ListPartsAsync(listPartRequest);
Debug.Assert(listPartResponse.Parts.Count == 3);

// Complete the multipart upload
CompleteMultipartUploadRequest compRequest = new CompleteMultipartUploadRequest
{
    BucketName = "amzn-s3-demo-bucket",
    Key = "Item1",
    UploadId = initResponse.UploadId,
    PartETags = new List<PartETag>
    {
        new PartETag { ETag = up1Response.ETag, PartNumber = 1 },
        new PartETag { ETag = up2Response.ETag, PartNumber = 2 },
        new PartETag { ETag = up3Response.ETag, PartNumber = 3 }
    }
};
CompleteMultipartUploadResponse compResponse = await client.CompleteMultipartUploadAsync(compRequest);

Version Information

.NET:
Supported in: 8.0 and newer, Core 3.1

.NET Standard:
Supported in: 2.0

.NET Framework:
Supported in: 4.7.2 and newer