Queries the metadata of an object, including ETag, Size, and LastModified. The content of the object is not returned.

Precautions

Note If the type of 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 an object of a specific version in a versioned bucket by sending a request that contains the x-oss-version-id header, you must have the oss:GetObjectVersion permission. For more information, see Attach a custom policy to a RAM user.

Versioning

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

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 request headers.

Response headers

Response headers Type Example Description
Content-Length String 344606 The object size. Unit: bytes.
ETag String 5B3C1A2E053D763E1B002CC607C5**** The entity tag (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 value of the object is the MD5 hash of the object content. If an object is created by using another method, the ETag value 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.

Default value: null.

x-oss-version-id String CAEQNRiBgIDMh4mD0BYiIDUzNDA4OGNmZjBjYTQ0YmI4Y2I4ZmVlYzJlNGVk**** The version ID of the object. This element is returned only if you query the metadata of an object of a specific version.

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 requests
    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 when the object is a file
    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
    Sample success responses when the object is a directory
    HTTP/1.1 200 OK
    x-oss-request-id: 559CC9BDC755F95A6448****
    Date: Wed, 31 Mar 2021 05:21:12 GMT
    ETag: "null"
    Last-Modified: Tue, 30 Mar 2021 06:07:48 GMT
    Content-Length: 0
    Connection: keep-alive
    Server: AliyunOSS
  • Query the metadata of an object in a versioned bucket
    Sample requests
    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
    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

SDK

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

Error codes

Error code HTTP status code Description
Not Found 404 The error message returned because the specified object does not exist.