Object Meta

Last Updated: Dec 07, 2017

Object Meta describes the attributes of files uploaded to OSS. These attributes are classified into two types: HTTP standard attributes (HTTP Headers) and User Meta (custom metadata). File metadata can be configured when files are uploaded or copied.

HTTP standard attributes

Name Description
Cache-Control Cache action of the web page when the object is downloaded
Content-Disposition Name of the object when downloaded
Content-Encoding Content encoding format when the object is downloaded
Content-Language Specifies the content language encoding when the object is downloaded
Expires Expiry time
Content-Length Size of the object
Content-Type File type of the object
Last-Modified Time of last modification

User Meta

This attribute allows you to enrich the description of objects using custom metadata. In OSS, all parameters prefixed with “x-oss-meta-“ are considered as User Meta, such as x-oss-meta-location. A single object can have multiple similar parameters, but the total size of all User Meta cannot exceed 8 KB. User Meta information is returned in the HTTP header during GetObject or HeadObject operations.

Set object Meta when uploading objects

You can set object Meta when uploading objects.


You can set object Meta when using multipart uploads.


Modify object Meta after uploading objects

To modify the object metadata without modifying the actual data, using the copy object interface is recommended. In this way, you only need to apply the new metadata in the HTTP header and set the copy source and destination addresses to the current address of the object.

Reference for using the function:

Retrieve object Meta

This feature applies when the you must retrieve object Meta, but not the object data.

Reference for using the function:

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