AWS SDK Version 3 for .NET
API Reference

AWS services or capabilities described in AWS Documentation may vary by region/location. Click Getting Started with Amazon AWS to see specific differences applicable to the China (Beijing) Region.

Container for the parameters to the GetObjectMetadata operation. The HEAD action retrieves metadata from an object without returning the object itself. This action is useful if you're only interested in an object's metadata. To use HEAD, you must have READ access to the object.

A HEAD request has the same options as a GET action on an object. The response is identical to the GET response except that there is no response body. Because of this, if the HEAD request generates an error, it returns a generic 404 Not Found or 403 Forbidden code. It is not possible to retrieve the exact exception beyond these error codes.

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 retrieve the metadata from the object, you must use the following headers:

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

  • 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 Amazon Web Services 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.

  • The last modified property in this case is the creation date of the object.

Request headers are limited to 8 KB in size. For more information, see Common Request Headers.

Consider the following when using request headers:

For more information about conditional requests, see RFC 7232.

Permissions

You need the relevant read object (or version) 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.

The following action is related to HeadObject:

Inheritance Hierarchy

System.Object
  Amazon.Runtime.AmazonWebServiceRequest
    Amazon.S3.Model.GetObjectMetadataRequest

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

Syntax

C#
public class GetObjectMetadataRequest : AmazonWebServiceRequest
         IAmazonWebServiceRequest

The GetObjectMetadataRequest type exposes the following members

Constructors

NameDescription
Public Method GetObjectMetadataRequest()

Properties

NameTypeDescription
Public Property BucketName System.String

Gets and sets the property BucketName.

The name of the bucket containing the object.

When using this action 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 action with an access point through the Amazon Web Services 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 S3 User Guide.

When using this action with Amazon S3 on Outposts, you must direct requests to the S3 on Outposts hostname. The S3 on Outposts hostname takes the form AccessPointName-AccountId.outpostID.s3-outposts.Region.amazonaws.com. When using this action using S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts bucket ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see Using S3 on Outposts in the Amazon S3 User Guide.

Public Property EtagToMatch System.String

ETag to be matched as a pre-condition for returning the object, otherwise a PreconditionFailed signal is returned.

Public Property EtagToNotMatch System.String

ETag that should not be matched as a pre-condition for returning the object, otherwise a PreconditionFailed signal is returned.

Public Property ExpectedBucketOwner System.String

Gets and sets the property ExpectedBucketOwner.

The account ID of the expected bucket owner. If the bucket is owned by a different account, the request will fail with an HTTP 403 (Access Denied) error.

Public Property Key System.String

The key of the object.

Public Property ModifiedSinceDate System.DateTime

This property is deprecated. Setting this property results in non-UTC DateTimes not being marshalled correctly. Use ModifiedSinceDateUtc instead. Setting either ModifiedSinceDate or ModifiedSinceDateUtc results in both ModifiedSinceDate and ModifiedSinceDateUtc being assigned, the latest assignment to either one of the two property is reflected in the value of both. ModifiedSinceDate is provided for backwards compatibility only and assigning a non-Utc DateTime to it results in the wrong timestamp being passed to the service.

Returns the object only if it has been modified since the specified time, otherwise returns a PreconditionFailed.

Public Property ModifiedSinceDateUtc System.DateTime

Returns the object only if it has been modified since the specified time, otherwise returns a PreconditionFailed.

Public Property PartNumber System.Nullable<System.Int32>

Part number of the object being read. This is a positive integer between 1 and 10,000. Effectively performs a 'ranged' HEAD request for the part specified. Useful querying about the size of the part and the number of parts in this object.

Public Property RequestPayer Amazon.S3.RequestPayer

Confirms that the requester knows that she or he will be charged for the request. Bucket owners need not specify this parameter in their requests.

Public Property ServerSideEncryptionCustomerMethod Amazon.S3.ServerSideEncryptionCustomerMethod

The Server-side encryption algorithm to be used with the customer provided key.

Public Property ServerSideEncryptionCustomerProvidedKey System.String

The base64-encoded encryption key for Amazon S3 to use to decrypt the object

Using the encryption key you provide as part of your request Amazon S3 manages both the encryption, as it writes to disks, and decryption, when you access your objects. Therefore, you don't need to maintain any data encryption code. The only thing you do is manage the encryption keys you provide.

When you retrieve an object, you must provide the same encryption key as part of your request. Amazon S3 first verifies the encryption key you provided matches, and then decrypts the object before returning the object data to you.

Important: Amazon S3 does not store the encryption key you provide.

Public Property ServerSideEncryptionCustomerProvidedKeyMD5 System.String

The MD5 of the customer encryption key specified in the ServerSideEncryptionCustomerProvidedKey property. The MD5 is base 64 encoded. This field is optional, the SDK will calculate the MD5 if this is not set.

Public Property UnmodifiedSinceDate System.DateTime

This property is deprecated. Setting this property results in non-UTC DateTimes not being marshalled correctly. Use UnmodifiedSinceDateUtc instead. Setting either UnmodifiedSinceDate or UnmodifiedSinceDateUtc results in both UnmodifiedSinceDate and UnmodifiedSinceDateUtc being assigned, the latest assignment to either one of the two property is reflected in the value of both. UnmodifiedSinceDate is provided for backwards compatibility only and assigning a non-Utc DateTime to it results in the wrong timestamp being passed to the service.

Returns the object only if it has not been modified since the specified time, otherwise returns a PreconditionFailed.

Public Property UnmodifiedSinceDateUtc System.DateTime

Returns the object only if it has not been modified since the specified time, otherwise returns a PreconditionFailed.

Public Property VersionId System.String

VersionId used to reference a specific version of the object.

Version Information

.NET Core App:
Supported in: 3.1

.NET Standard:
Supported in: 2.0

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