You can call this operation to complete the multipart upload tasks of an object.

Usage notes

When you call the CompleteMultipartUpload operation, you must provide a complete list of all valid parts, which includes the part number and ETag of each part. After OSS receives the list of parts, OSS verifies the validity of each part one by one. After all these parts are validated, OSS combines these parts into a complete object.

  • Confirm the size of each part

    When you perform the CompleteMultipartUpload operation, OSS checks whether each part except the last part is larger than or equal to 100 KB in size and verifies the part number and ETag of each part that are provided in the part list. Therefore, when a part is uploaded, the client must record not only the part number of the part but also the ETag value of the part returned from the server.

  • Handle requests

    It may take a while for OSS to process the CompleteMultipartUpload request. If the client is disconnected from OSS during this period, OSS continues to process the request.

  • PartNumber

    OSS verifies the value of PartNumber when you call the CompleteMultipartUpload operation.

    The value of PartNumber ranges from 1 to 10000. The part numbers listed in the request do not have to be consecutive but must be sorted in ascending order. For example, if the part number of the first part is 1, the part number of the second part can be 5.

  • UploadId

    An object can be uploaded by multiple upload tasks that have independent upload IDs. When one upload task is completed, the corresponding upload ID becomes invalid and the upload IDs of other upload tasks are not affected.

  • x-oss-server-side-encryption request header

    If the x-oss-server-side-encryption header is specified in an InitiateMultipartUpload request, this header is returned in the response to the request. The value of the x-oss-server-side-encryption header in the response indicates the method used to encrypt the object on the OSS server.

Versioning

You can call CompleteMultipartUpload to complete the multipart upload task of an object when versioning is enabled for the bucket to which the object is uploaded. In this case, OSS generates a unique version ID for the object, and returns the version ID as the x-oss-version-id header in the response.

Request structure

POST /ObjectName? uploadId=UploadId HTTP/1.1
Host: BucketName.oss-cn-hangzhou.aliyuncs.com
Date: GMT Date
Content-Length: Size
Authorization: Signature
<CompleteMultipartUpload>
<Part>
<PartNumber>PartNumber</PartNumber>
<ETag>ETag</ETag>
</Part>
...
</CompleteMultipartUpload>

Request parameters

You can configure the Encoding-type parameter in a CompleteMultipartUpload request. OSS uses the specified encoding type to encode the object name in the response.

Parameter Type Description
Encoding-type String The encoding type of the object name in the response. Only URL encoding is supported.

The object name can contain any characters that are encoded in UTF-8. However, the XML 1.0 standard cannot be used to parse control characters such as characters whose ASCII values range from 0 to 10. You can configure this parameter to encode the object names in the response.

Default value: null

Valid value: url

For more information about other common request headers such as Host and Date, see Common HTTP headers.

Request headers

Header Type Required Description
x-oss-forbid-overwrite String No Specifies whether the object with the same object name is overwritten when you perform the CompleteMultipartUpload operation.
  • By default, if x-oss-forbid-overwrite is not specified, the object that has the same name is overwritten.
  • If the value of x-oss-forbid-overwrite is set to true, the object that has the same object name cannot be overwritten. If the value of x-oss-forbid-overwrite is set to false, the object that has the same object name can be overwritten.
Note
  • The x-oss-forbid-overwrite request header is invalid when the versioning state of the target bucket is Enabled or Suspended. In this case, the CompleteMultipartUpload operation overwrites the object with the same name.
  • If you specify the x-oss-forbid-overwrite request header, the query per second (QPS) performance of OSS may be degraded. If you want to use the x-oss-forbid-overwrite request header for a large number of operations (QPS greater than 1000), submit a ticket.
x-oss-complete-all:yes String No Specifies whether to list all parts uploaded by using the current upload ID.
  • If x-oss-complete-all:yes is specified in the request, OSS lists all parts that are uploaded by using the current upload ID, sorts the parts by their part numbers, and then performs the CompleteMultipartUpload operation. OSS cannot detect parts that are not uploaded or being uploaded in the CompleteMultipartUpload operation. Therefore, you must ensure that all parts are uploaded before you perform the CompleteMultipartUpload operation.
  • If x-oss-complete-all:yes is specified in the request, the request body cannot be specified. Otherwise, an error occurs.
  • The format of the response remains unchanged if x-oss-complete-all:yes is specified in the request.

Request elements

Element Type Description
CompleteMultipartUpload Container The container that stores the content of the CompleteMultipartUpload request.

Child node: Part

Parent node: none
ETag String The ETag values that are returned by OSS after parts are uploaded.

Parent node: Part
Part Container The container that stores the information about the uploaded part.

Child nodes: ETag and PartNumber

Parent node: CompleteMultipartUpload
PartNumber Integer The number of parts.

Parent node: Part

Response elements

Element Type Description
Bucket String The name of the bucket.

Parent node: CompleteMultipartUploadResult
CompleteMultipartUploadResult Container The container that stores the result of the CompleteMultipartUpload request.

Child nodes: Bucket, Key, ETag, and Location

Parent node: none
ETag String The ETag that is generated when an object is created. Etags are used to identify the content of the objects.

The ETag value of an object created by CompleteMultipartUpload is the UUID of the object.

Note The ETag value of an object can be used to check whether the object content is changed. However, we recommend that you do not use the ETag of an object as the MD5 hash of the object to verify data integrity.

Parent node: CompleteMultipartUploadResult
Location String The URL used to access the uploaded object.

Parent node: CompleteMultipartUploadResult
Key String The name of the uploaded object.

Parent node: CompleteMultipartUploadResult
EncodingType String The encoding type of the object names in the response. If this parameter is specified in the request, the object name is encoded in the response.

Parent node: InitiateMultipartUploadResult

Examples

  • Sample request 
    POST /multipart.data? uploadId=0004B9B2D2F7815C432C9057C031****  HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Content-Length: 1056
Date: Fri, 24 Feb 2012 10:19:18 GMT
Authorization: OSS qn6qrrqxo2oawuk53otf****:8VwFhFUWmVecK6jQlHlXMK/z****
<CompleteMultipartUpload> 
    <Part> 
        <PartNumber>1</PartNumber>  
        <ETag>"3349DC700140D7F86A0784842780****"</ETag> 
    </Part>  
    <Part> 
        <PartNumber>5</PartNumber>  
        <ETag>"8EFDA8BE206636A695359836FE0A****"</ETag> 
    </Part>  
    <Part> 
        <PartNumber>8</PartNumber>  
        <ETag>"8C315065167132444177411FDA14****"</ETag> 
    </Part> 
</CompleteMultipartUpload>
    Sample response 
    HTTP/1.1 200 OK
Server: AliyunOSS
Content-Length: 329
Content-Type: Application/xml
Connection: keep-alive
x-oss-request-id: 594f0751-3b1e-168f-4501-4ac71d21****
Date: Fri, 24 Feb 2012 10:19:18 GMT
<? xml version="1.0" encoding="UTF-8"? >
<CompleteMultipartUploadResult xmlns="http://doc.oss-cn-hangzhou.aliyuncs.com">
    <Location>http://oss-example.oss-cn-hangzhou.aliyuncs.com /multipart.data</Location>
    <Bucket>oss-example</Bucket>
    <Key>multipart.data</Key>
    <ETag>"B864DB6A936D376F9F8D3ED3BBE540****"</ETag>
</CompleteMultipartUploadResult>
  • Sample request for a versioned bucket 
    POST /multipart.data? uploadId=63C06A5CFF6F4AE4A6BB3AD7F01C****  HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Content-Length: 223
Date: Tue, 09 Apr 2019 07:01:56 GMT
Authorization: OSS 6jftttm6x6s****:XljBrYBYxDnxKdFMj9WYI6qu****
<CompleteMultipartUpload> 
    <Part> 
        <PartNumber>1</PartNumber>  
        <ETag>"25A9F4ABFCC05743DF6E2C886C56****"</ETag> 
    </Part>  
    <Part> 
        <PartNumber>5</PartNumber>  
        <ETag>"25A9F4ABFCC05743DF6E2C886C56****"</ETag> 
    </Part>  
</CompleteMultipartUpload>
    Sample response 
    HTTP/1.1 200 OK
Server: AliyunOSS
Content-Length: 314
Content-Type: Application/xml
Connection: keep-alive
x-oss-version-id: CAEQMxiBgID6v86D0BYiIDc3ZDI0YTBjZGQzYjQ2Mjk4OWVjYWNiMDljYzhlN****
x-oss-request-id: 5CAC4364B7AEADE017000662
Date: Tue, 09 Apr 2019 07:01:56 GMT
<? xml version="1.0" encoding="UTF-8"? >
<CompleteMultipartUploadResult>
  <Location>http://oss-example.oss-cn-hangzhou.aliyuncs.com/multipart.data</Location>
  <Bucket>oss-example</Bucket>
  <Key>multipart.data</Key>
  <ETag>"097DE458AD02B5F89F9D0530231876****"</ETag>
</CompleteMultipartUploadResult>

SDK

You can use SDKs for the following programming languages to call the CompleteMultipartUpload operation:

Error codes

Error code HTTP status code Description
InvalidDigest 400 The error message returned because the Content-MD5 value in the request and the MD5 hash calculated by OSS are inconsistent. To ensure that no errors occur during data transmission over the network, you can include the Content-MD5 value in the request. OSS calculates the MD5 hash of the uploaded data and compares it with the Content-MD5 value.
FileAlreadyExists 409 The error message returned because an object with the same name already exists when the request contains the x-oss-forbid-overwrite header and the value of this header is set to true.