AWS SDK Version 3 for .NET
API Reference

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Retrieves objects from Amazon S3. To use GET, you must have READ access to the object. If you grant READ access to the anonymous user, you can return the object without using an authorization header.

An Amazon S3 bucket has no directory hierarchy such as you would find in a typical computer file system. You can, however, create a logical hierarchy by using object key names that imply a folder structure. For example, instead of naming an object sample.jpg, you can name it photos/2006/February/sample.jpg.

To get an object from such a logical hierarchy, specify the full key name for the object in the GET operation. For a virtual hosted-style request example, if you have the object photos/2006/February/sample.jpg, specify the resource as /photos/2006/February/sample.jpg. For a path-style request example, if you have the object photos/2006/February/sample.jpg in the bucket named examplebucket, specify the resource as /examplebucket/photos/2006/February/sample.jpg. For more information about request types, see HTTP Host Header Bucket Specification.

To distribute large files to many people, you can save bandwidth costs by using BitTorrent. For more information, see Amazon S3 Torrent. For more information about returning the ACL of an object, see GetObjectAcl.

If the object you are retrieving is stored in the GLACIER or DEEP_ARCHIVE storage classes, before you can retrieve the object you must first restore a copy using . Otherwise, this operation returns an InvalidObjectStateError error. For information about restoring archived objects, see Restoring Archived Objects.

Encryption request headers, like x-amz-server-side-encryption, should not be sent for GET requests if your object uses server-side encryption with CMKs stored in AWS KMS (SSE-KMS) or server-side encryption with Amazon S3–managed encryption keys (SSE-S3). If your object does use these types of keys, you’ll get an HTTP 400 BadRequest error.

If you encrypt an object by using server-side encryption with customer-provided encryption keys (SSE-C) when you store the object in Amazon S3, then when you GET the object, you must use the following headers:

For more information about SSE-C, see Server-Side Encryption (Using Customer-Provided Encryption Keys).

Assuming you have permission to read object tags (permission for the s3:GetObjectVersionTagging action), the response also returns the x-amz-tagging-count header that provides the count of number of tags associated with the object. You can use GetObjectTagging to retrieve the tag set associated with an object.

Permissions

You need the s3:GetObject permission for this operation. For more information, see Specifying Permissions in a Policy. If the object you request does not exist, the error Amazon S3 returns depends on whether you also have the s3:ListBucket permission.

Versioning

By default, the GET operation returns the current version of an object. To return a different version, use the versionId subresource.

If the current version of the object is a delete marker, Amazon S3 behaves as if the object was deleted and includes x-amz-delete-marker: true in the response.

For more information about versioning, see PutBucketVersioning.

Overriding Response Header Values

There are times when you want to override certain response header values in a GET response. For example, you might override the Content-Disposition response header value in your GET request.

You can override values for a set of response headers using the following query parameters. These response header values are sent only on a successful request, that is, when status code 200 OK is returned. The set of headers you can override using these parameters is a subset of the headers that Amazon S3 accepts when you create an object. The response headers that you can override for the GET response are Content-Type, Content-Language, Expires, Cache-Control, Content-Disposition, and Content-Encoding. To override these header values in the GET response, you use the following request parameters.

You must sign the request, either using an Authorization header or a presigned URL, when using these parameters. They cannot be used with an unsigned (anonymous) request.

Additional Considerations about Request Headers

If both of the If-Match and If-Unmodified-Since headers are present in the request as follows: If-Match condition evaluates to true, and; If-Unmodified-Since condition evaluates to false; then, S3 returns 200 OK and the data requested.

If both of the If-None-Match and If-Modified-Since headers are present in the request as follows: If-None-Match condition evaluates to false, and; If-Modified-Since condition evaluates to true; then, S3 returns 304 Not Modified response code.

For more information about conditional requests, see RFC 7232.

The following operations are related to GetObject:

Note:

For .NET Core, PCL and Unity this operation is only available in asynchronous form. Please refer to GetObjectAsync.

Namespace: Amazon.S3
Assembly: AWSSDK.S3.dll
Version: 3.x.y.z

Syntax

C#
public abstract GetObjectResponse GetObject(
         String bucketName,
         String key
)
Parameters
bucketName
Type: System.String

The bucket name containing the object. When using this API with an access point, you must direct requests to the access point hostname. The access point hostname takes the form AccessPointName-AccountId.s3-accesspoint.Region.amazonaws.com. When using this operation using an access point through the AWS SDKs, you provide the access point ARN in place of the bucket name. For more information about access point ARNs, see Using Access Points in the Amazon Simple Storage Service Developer Guide.

key
Type: System.String

Key of the object to get.

Return Value
The response from the GetObject service method, as returned by S3.

Version Information

.NET Framework:
Supported in: 4.5, 4.0, 3.5

Portable Class Library:
Supported in: Windows Store Apps
Supported in: Xamarin Android
Supported in: Xamarin iOS (Unified)
Supported in: Xamarin.Forms

Unity:
Supported Versions: 4.6 and above
Supported Platforms: Android, iOS, Standalone

See Also