Query the metadata of an object by calling GetObjectMeta - Object Storage Service

Queries the metadata of an object, including the ETag, size, and last modified time of the object. The content of the object is not returned.

Usage notes

Note

If the object is a symbolic link, the information about the symbolic link is returned.

To query the metadata of an object in an unversioned bucket, you must have the oss:GetObject permission. To query the metadata of a specific version of an object in a versioning-enabled bucket, you must have the oss:GetObjectVersion permission. To specify the version of the object, specify the x-oss-version-id header in the request. For more information, see Attach a custom policy to a RAM user.

Versioning

By default, the GetObjectMeta operation queries the metadata of the current version of an object. If the current version of the object is a delete marker, Object Storage Service (OSS) returns 404 Not Found. If you specify a version ID in the request, OSS returns the metadata of the specified version of the object.

Request syntax

HEAD /ObjectName?objectMeta HTTP/1.1
Host: BucketName.oss-cn-hangzhou.aliyuncs.com
Date: GMT Date
Authorization: SignatureValue

Request headers

This request contains only common request headers. For more information, see Common HTTP headers.

Response headers

Response header	Type	Example	Description
Content-Length	String	344606	The size of the object. Unit: bytes.
ETag	String	5B3C1A2E053D763E1B002CC607C5****	The ETag that is generated when an object is created. ETags are used to identify the content of objects. If an object is created by calling the PutObject operation, the ETag of the object is the MD5 hash of the object content. If an object is created by using another method, the ETag of the object is not the MD5 hash of the object content but a unique value calculated based on a specific rule. The ETag of an object can be used to check whether the object content changes. However, we recommend that you use the MD5 hash of an object rather than the ETag value of the object to verify data integrity. By default, this parameter is left empty.
x-oss-last-access-time	String	Tue, 30 Mar 2021 06:07:48 GMT	The time when the object was last accessed. The time must be the GMT time specified in HTTP/1.1. If access tracking is enabled, the value of this header is continuously updated as the object is accessed. If access tracking is enabled and then disabled, the value of this header is the time when the object was last accessed. Important The last access time of an object is updated asynchronously. OSS guarantees that the last access time of the object is updated within 24 hours. If you access an object multiple times within 24 hours, the last access time of the object is updated to the time when you access the object for the first time within the period.
Last-Modified	String	Fri, 24 Feb 2012 06:07:48 GMT	The time when the object was last modified. The time must be the GMT time specified in HTTP/1.1.
x-oss-version-id	String	CAEQNRiBgIDMh4mD0BYiIDUzNDA4OGNmZjBjYTQ0YmI4Y2I4ZmVlYzJlNGVk****	The version ID of the object. This header is returned only if you query the metadata of a specific version of the object.

The response to this request contains common response headers. For more information, see Common response headers.

Examples

Query the metadata of an object in an unversioned bucket

Sample request

HEAD /oss.jpg?objectMeta HTTP/1.1
Host: oss-example.oss-cn-hangzhou.aliyuncs.com
Date: Wed, 29 Apr 2015 05:21:12 GMT
Authorization: OSS qn6qrrqxo2oawuk53otf****:CTkuxpLAi4XZ+WwIfNm0Fmgb****

Sample responses

Important

If you create a directory by calling the CreateDirectory operation after you enable hierarchical namespace for a bucket, null is returned for the ETag when you call the GetObjectMeta operation to query the directory information.

If access tracking is disabled for the bucket

HTTP/1.1 200 OK
x-oss-request-id: 559CC9BDC755F95A6448****
Date: Wed, 29 Apr 2015 05:21:12 GMT
ETag: "5B3C1A2E053D763E1B002CC607C5****"
Last-Modified: Fri, 24 Feb 2012 06:07:48 GMT
Content-Length: 344606
Connection: keep-alive
Server: AliyunOSS

If access tracking is enabled for a bucket

HTTP/1.1 200 OK
x-oss-request-id: 559CC9BDC755F95A6448****
Date: Wed, 29 Apr 2015 05:21:12 GMT
ETag: "5B3C1A2E053D763E1B002CC607C5****"
x-oss-last-access-time: Thu, 14 Oct 2021 11:49:05 GMT
Last-Modified: Fri, 24 Feb 2012 06:07:48 GMT
Content-Length: 344606
Connection: keep-alive
Server: AliyunOSS

Query the metadata of an object in a versioning-enabled bucket

Sample request

GET /example?objectMeta&versionId=CAEQNRiBgIDMh4mD0BYiIDUzNDA4OGNmZjBjYTQ0YmI4Y2I4ZmVlYzJlNGVk**** HTTP/1.1
Host: versioning-test.oss-cn-hangzhou.aliyuncs.com
Date: Tue, 09 Apr 2019 06:24:00 GMT
Authorization: OSS 5n4nrhyqrcs****:i/M/c36KzrOEA/bBSHLllIAt****

Sample responses

If access tracking is disabled for the bucket

HTTP/1.1 200 OK
x-oss-version-id: CAEQNRiBgIDMh4mD0BYiIDUzNDA4OGNmZjBjYTQ0YmI4Y2I4ZmVlYzJlNGVk****
x-oss-request-id: 5CAC3A80B7AEADE0170005F6
Date: Tue, 09 Apr 2019 06:24:00 GMT
ETag: "1CF5A685959CA2ED8DE6E5F8ACC2****"
Last-Modified: Tue, 09 Apr 2019 06:24:00 GMT
Content-Length: 119914
Connection: keep-alive
Server: AliyunOSS

If access tracking is enabled for the bucket

HTTP/1.1 200 OK
x-oss-version-id: CAEQNRiBgIDMh4mD0BYiIDUzNDA4OGNmZjBjYTQ0YmI4Y2I4ZmVlYzJlNGVk****
x-oss-request-id: 5CAC3A80B7AEADE0170005F6
Date: Tue, 09 Apr 2019 06:24:00 GMT
ETag: "1CF5A685959CA2ED8DE6E5F8ACC2****"
x-oss-last-access-time: Thu, 14 Oct 2021 11:49:05 GMT
Last-Modified: Tue, 09 Apr 2019 06:24:00 GMT
Content-Length: 119914
Connection: keep-alive
Server: AliyunOSS

OSS SDKs

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

References

For more information about object metadata, see Manage object metadata.

Error codes

Error code	HTTP status code	Description
Not Found	404	The specified object does not exist.