Use a GET object request to:
- Download an object
- List the uploaded parts of an object
- List object ACLs
- Get an object's encryption information
- Get an object's retention configuration
You should notuse a GET object request to retrieve general object metadata, because doing so incurs charges associated with downloading the entire object. Use a HEAD object request instead.
To download an object you make a GET request that is scoped to a bucket
and object. You can also use various request headers to further scope the
request. The request returns the object's contents in the response body. To
list an object's ACLs you make a GET request that is scoped to a bucket and
object and you use the acl 
query string parameter. The ACLs are
returned in an XML document in the response body.
If you make a GET request for an object that doesn't exist, you get a 404 Not Found 
status
code and the body of the error response contains NoSuchKey 
in the Code 
element.
Common request headers
The following are common request headers for GET object requests.
| Header | Description | Required | 
|---|---|---|
| The authentication string for the request. Required for objects without public read access. | Maybe | |
| The URI for Cloud Storage. For more information, see Request Endpoints . | Yes | |
| The project to be billed for charges associated with the request. | No | 

