GetObjectAttributes - Amazon Simple Storage Service
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GetObjectAttributes

Retrieves all the metadata from an object without returning the object itself. This action is useful if you're interested only in an object's metadata. To use GetObjectAttributes, you must have READ access to the object.

GetObjectAttributes combines the functionality of HeadObject and ListParts. All of the data returned with each of those individual calls can be returned with a single call to GetObjectAttributes.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you retrieve the metadata from the object, you must use the following headers:

  • x-amz-server-side-encryption-customer-algorithm

  • x-amz-server-side-encryption-customer-key

  • x-amz-server-side-encryption-customer-key-MD5

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys) in the Amazon S3 User Guide.

Note
  • Encryption request headers, such as x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with Amazon KMS keys stored in Amazon Key Management Service (SSE-KMS) or server-side encryption with Amazon S3 managed keys (SSE-S3). If your object does use these types of keys, you'll get an HTTP 400 Bad Request error.

  • The last modified property in this case is the creation date of the object.

Consider the following when using request headers:

  • If both of the If-Match and If-Unmodified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 200 OK and the data requested:

    • If-Match condition evaluates to true.

    • If-Unmodified-Since condition evaluates to false.

  • If both of the If-None-Match and If-Modified-Since headers are present in the request as follows, then Amazon S3 returns the HTTP status code 304 Not Modified:

    • If-None-Match condition evaluates to false.

    • If-Modified-Since condition evaluates to true.

For more information about conditional requests, see RFC 7232.

Permissions

The permissions that you need to use this operation depend on whether the bucket is versioned. If the bucket is versioned, you need both the s3:GetObjectVersion and s3:GetObjectVersionAttributes permissions for this operation. If the bucket is not versioned, you need the s3:GetObject and s3:GetObjectAttributes permissions. For more information, see Specifying Permissions in a Policy in the Amazon S3 User Guide. If the object that you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

  • If you have the s3:ListBucket permission on the bucket, Amazon S3 returns an HTTP status code 404 Not Found ("no such key") error.

  • If you don't have the s3:ListBucket permission, Amazon S3 returns an HTTP status code 403 Forbidden ("access denied") error.

The following actions are related to GetObjectAttributes:

Request Syntax

GET /{Key+}?attributes&versionId=VersionId HTTP/1.1 Host: Bucket.s3.amazonaws.com x-amz-max-parts: MaxParts x-amz-part-number-marker: PartNumberMarker x-amz-server-side-encryption-customer-algorithm: SSECustomerAlgorithm x-amz-server-side-encryption-customer-key: SSECustomerKey x-amz-server-side-encryption-customer-key-MD5: SSECustomerKeyMD5 x-amz-request-payer: RequestPayer x-amz-expected-bucket-owner: ExpectedBucketOwner x-amz-object-attributes: ObjectAttributes

URI Request Parameters

The request uses the following URI parameters.

Bucket

The name of the bucket that contains the object.

When using this action with an access point, 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 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.

When you use this action with Amazon 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 through the Amazon SDKs, you provide the Outposts access point ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see What is S3 on Outposts in the Amazon S3 User Guide.

Required: Yes

Key

The object key.

Length Constraints: Minimum length of 1.

Required: Yes

versionId

The version ID used to reference a specific version of the object.

x-amz-expected-bucket-owner

The account ID of the expected bucket owner. If the bucket is owned by a different account, the request fails with the HTTP status code 403 Forbidden (access denied).

x-amz-max-parts

Sets the maximum number of parts to return.

x-amz-object-attributes

An XML header that specifies the fields at the root level that you want returned in the response. Fields that you do not specify are not returned.

Valid Values: ETag | Checksum | ObjectParts | StorageClass | ObjectSize

Required: Yes

x-amz-part-number-marker

Specifies the part after which listing should begin. Only parts with higher part numbers will be listed.

x-amz-request-payer

Confirms that the requester knows that they will be charged for the request. Bucket owners need not specify this parameter in their requests. For information about downloading objects from Requester Pays buckets, see Downloading Objects in Requester Pays Buckets in the Amazon S3 User Guide.

Valid Values: requester

x-amz-server-side-encryption-customer-algorithm

Specifies the algorithm to use when encrypting the object (for example, AES256).

x-amz-server-side-encryption-customer-key

Specifies the customer-provided encryption key for Amazon S3 to use in encrypting data. This value is used to store the object and then it is discarded; Amazon S3 does not store the encryption key. The key must be appropriate for use with the algorithm specified in the x-amz-server-side-encryption-customer-algorithm header.

x-amz-server-side-encryption-customer-key-MD5

Specifies the 128-bit MD5 digest of the encryption key according to RFC 1321. Amazon S3 uses this header for a message integrity check to ensure that the encryption key was transmitted without error.

Request Body

The request does not have a request body.

Response Syntax

HTTP/1.1 200 x-amz-delete-marker: DeleteMarker Last-Modified: LastModified x-amz-version-id: VersionId x-amz-request-charged: RequestCharged <?xml version="1.0" encoding="UTF-8"?> <GetObjectAttributesOutput> <ETag>string</ETag> <Checksum> <ChecksumCRC32>string</ChecksumCRC32> <ChecksumCRC32C>string</ChecksumCRC32C> <ChecksumSHA1>string</ChecksumSHA1> <ChecksumSHA256>string</ChecksumSHA256> </Checksum> <ObjectParts> <IsTruncated>boolean</IsTruncated> <MaxParts>integer</MaxParts> <NextPartNumberMarker>integer</NextPartNumberMarker> <PartNumberMarker>integer</PartNumberMarker> <Part> <ChecksumCRC32>string</ChecksumCRC32> <ChecksumCRC32C>string</ChecksumCRC32C> <ChecksumSHA1>string</ChecksumSHA1> <ChecksumSHA256>string</ChecksumSHA256> <PartNumber>integer</PartNumber> <Size>integer</Size> </Part> ... <PartsCount>integer</PartsCount> </ObjectParts> <StorageClass>string</StorageClass> <ObjectSize>long</ObjectSize> </GetObjectAttributesOutput>

Response Elements

If the action is successful, the service sends back an HTTP 200 response.

The response returns the following HTTP headers.

Last-Modified

The creation date of the object.

x-amz-delete-marker

Specifies whether the object retrieved was (true) or was not (false) a delete marker. If false, this response header does not appear in the response.

x-amz-request-charged

If present, indicates that the requester was successfully charged for the request.

Valid Values: requester

x-amz-version-id

The version ID of the object.

The following data is returned in XML format by the service.

GetObjectAttributesOutput

Root level tag for the GetObjectAttributesOutput parameters.

Required: Yes

Checksum

The checksum or digest of the object.

Type: Checksum data type

ETag

An ETag is an opaque identifier assigned by a web server to a specific version of a resource found at a URL.

Type: String

ObjectParts

A collection of parts associated with a multipart upload.

Type: GetObjectAttributesParts data type

ObjectSize

The size of the object in bytes.

Type: Long

StorageClass

Provides the storage class information of the object. Amazon S3 returns this header for all objects except for S3 Standard storage class objects.

For more information, see Storage Classes.

Type: String

Valid Values: STANDARD | REDUCED_REDUNDANCY | STANDARD_IA | ONEZONE_IA | INTELLIGENT_TIERING | GLACIER | DEEP_ARCHIVE | OUTPOSTS | GLACIER_IR

See Also

For more information about using this API in one of the language-specific Amazon SDKs, see the following: