Object metadata describes the attributes of objects uploaded to OSS. These attributes are classified into two types: HTTP standard attributes (HTTP header fields) and user metadata (user-defined object metadata).
The following section describes the HTTP standard attributes and user metadata:
- HTTP standard attributes
Name Description Content-Type The type of the object. Content-Encoding The compression type of the object. Valid values:
- gzip: uses the Lempel-Ziv coding (LZ77) compression algorithm and 32-bit CRC.
- compress: uses the Lempel-Ziv-Welch (LZW) compression algorithm.
- deflate: uses the zlib structure and deflate compression algorithm.
- identity: Data is not compressed. This is the default value.
- br: uses the Brotli encoding method.
Content-Language The language of the object. Content-Disposition The format of the object. Valid values:
Notice When you access an object in OSS by using a browser, you can directly download the object by setting Content-Disposition to inline under the following conditions:
- inline: The object is opened by using an application such as a browser.
- attachment: downloads an object to a local computer. You can use the additional
filenameto set the name of the object that can be saved locally. Example:
- The object is a web page object. You access the object without using the custom domain bound to the bucket.
- The object is an image and the bucket is created after September 23, 2019. You access the object without using the custom domain name bound to the bucket.
- The object is not supported for browsers to preview.
Cache-Control The cache settings of the object. Common settings:
- no-cache: The cache cannot be used directly. It must be first verified by the server.
- no-store: No cache is used.
- public: The object can be cached on each node in the route in which the response is returned.
- private: The object can be cached only in the browser of the client.
- max-age=<seconds>: the cache duration. Unit: seconds.
public, max-age=20indicates that the object is cached for 20 seconds.
Expires The time the object expires in GMT. If
max-age=<seconds>is set for Cache-Control,
max-age=<seconds>takes precedence over Expires.
Last-Modified The time when the object is last modified. Content-Length The size of the object.
- User Meta
User metadata allows you to better describe objects. In OSS, all parameters prefixed with
x-oss-meta-are considered as user metadata. Example:
x-oss-meta-location. An object may have multiple similar parameters, but the total size of the user metadata cannot exceed 8 KB. User metadata is returned in the HTTP header of responses to GetObject or HeadObject requests.
|Console||A user-friendly and intuitive web application|
|ossbrowser||An easy-to-operate graphical tool|
|ossutil||A high-performance command-line tool|
|Java SDK||SDK demos for various programming languages|