Table of Contents

Class GetObjectMetadataRequest

Namespace
Amazon.S3.Model
Assembly
AWSSDK.S3.dll

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:

  • x-amz-server-side-encryption-customer-algorithm

  • x-amz-server-side-encryption-customer-key

  • x-amz-server-side-encryption-customer-key-MD5

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

note

  • 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:

  • Consideration 1 – 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 Amazon S3 returns 

    200 OK
    and the data requested.

  • Consideration 2 – 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 Amazon S3 returns the 

    304 Not Modified
    response code.

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.

  • If you have the 

    s3:ListBucket
    permission on the bucket, Amazon S3 returns an HTTP status code 404 ("no such key") error.

  • If you don’t have the 

    s3:ListBucket
    permission, Amazon S3 returns an HTTP status code 403 ("access denied") error.

The following action is related to 

HeadObject
: 
public class GetObjectMetadataRequest : AmazonWebServiceRequest
Inheritance
GetObjectMetadataRequest

Constructors

GetObjectMetadataRequest() 

public GetObjectMetadataRequest()

Properties

BucketName

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 you use 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 you use this action with S3 on Outposts through the Amazon Web Services SDKs, you provide the Outposts access point ARN in place of the bucket name. For more information about S3 on Outposts ARNs, see What is S3 on Outposts in the Amazon S3 User Guide. 
public string BucketName { get; set; }

Property Value

string

ChecksumMode

Gets and sets the property ChecksumMode.

This must be enabled to retrieve the checksum.

In addition, if you enable 

ChecksumMode
and the object is KMS encrypted, you must have permission to the 
kms:Decrypt
action for the request to succeed. 
public ChecksumMode ChecksumMode { get; set; }

Property Value

ChecksumMode

EtagToMatch

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

public string EtagToMatch { get; set; }

Property Value

string

EtagToNotMatch

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

public string EtagToNotMatch { get; set; }

Property Value

string

ExpectedBucketOwner

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 string ExpectedBucketOwner { get; set; }

Property Value

string

Key

The key of the object.

public string Key { get; set; }

Property Value

string

Remarks

This property will be used as part of the resource path of the HTTP request. In .NET the System.Uri class is used to construct the uri for the request. The System.Uri class will canonicalize the uri string by compacting characters like "..". /// For example an object key of "foo/../bar/file.txt" will be transformed into "bar/file.txt" because the ".." is interpreted as use parent directory. For further information view the documentation for the Uri class: https://docs.microsoft.com/en-us/dotnet/api/system.uri

ModifiedSinceDate

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. 
[Obsolete("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.", false)]
public DateTime ModifiedSinceDate { get; set; }

Property Value

DateTime

ModifiedSinceDateUtc

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

public DateTime ModifiedSinceDateUtc { get; set; }

Property Value

DateTime

PartNumber

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 int? PartNumber { get; set; }

Property Value

int?

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 RequestPayer RequestPayer { get; set; }

Property Value

RequestPayer

ServerSideEncryptionCustomerMethod

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

public ServerSideEncryptionCustomerMethod ServerSideEncryptionCustomerMethod { get; set; }

Property Value

ServerSideEncryptionCustomerMethod

ServerSideEncryptionCustomerProvidedKey

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 string ServerSideEncryptionCustomerProvidedKey { get; set; }

Property Value

string

ServerSideEncryptionCustomerProvidedKeyMD5

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 string ServerSideEncryptionCustomerProvidedKeyMD5 { get; set; }

Property Value

string

UnmodifiedSinceDate

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. 
[Obsolete("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.", false)]
public DateTime UnmodifiedSinceDate { get; set; }

Property Value

DateTime

UnmodifiedSinceDateUtc

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

public DateTime UnmodifiedSinceDateUtc { get; set; }

Property Value

DateTime

VersionId

VersionId used to reference a specific version of the object.

public string VersionId { get; set; }

Property Value

string