Object metadata describes the attributes of objects uploaded to OSS. These attributes include standard HTTP attributes (HTTP headers) and user metadata.
|Content-Type||The content type of the object. The browser determines the format and encoding type
used to read the object based on the content type of the object. If this attribute
is not specified, the value is generated based on the extension of the object. If
the object does not have an extension, the default value
|Content-Encoding||The encoding method of the object. Default value: identity.
|Content-Language||The language of the object.|
|Content-Disposition||The method based on which the object is accessed.
Notice When you access an object in OSS by using a browser, the object is downloaded even if the Content-Disposition header is set to inline in the following scenarios:
|Cache-Control||The caching behavior for the object.
|Expires||The expiration time of the cache in GMT. Example:
|Last-Modified||The time when the object is last modified.|
|Content-Length||The size of the object.|
OSS considers parameters prefixed with
x-oss-meta- to be user metadata. Example:
x-oss-meta-last-modified:20200909, which indicates that a file is last modified on September 9, 2020.
- An object may have multiple similar parameters. However, the total size of the user metadata of an object cannot exceed 8 KB.
- When you call the GetObject or HeadObject operation, the user metadata of the object is returned as response headers.
The following table describes the methods that you can use to configure, query, and modify the metadata of objects.
|Console||A user-friendly and intuitive web application|
|ossbrowser||An easy-to-use graphical tool|
|ossutil||A high-performance command-line tool|
|Java SDK||SDK demos for various programming languages|