Updated on 2023-12-25 GMT+08:00

Copying an Object

If you have any questions during the development, post them on the Issues page of GitHub. For details about parameters and usage of each API, see the API Reference.

The object copy operation can create a copy for an existing object in OBS.

You can call ObsClient.CopyObject to copy an object. When copying an object, you can specify properties and ACL for it.

  • If the source object to be copied is in the Archive storage class, you must restore it first.

Copying an Object in Simple Mode

Sample code:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);

// Copy an object.
try
{
    CopyObjectRequest request = new CopyObjectRequest();
    request.SourceBucketName = "sourcebucketname";
    request.SourceObjectKey = "sourceobjectname";
    request.BucketName = "destbucketname";
    request.ObjectKey = "destobjectName";
    CopyObjectResponse response = client.CopyObject(request);
    Console.WriteLine("Copy object response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
} 

Rewriting Object Properties

The following sample code shows how to rewrite object properties.

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
//Rewrite object properties.
try
{
    CopyObjectRequest request = new CopyObjectRequest();
    request.SourceBucketName = "sourcebucketname";
    request.SourceObjectKey = "sourceobjectname";
    request.BucketName = "destbucketname";
    request.ObjectKey = "destobjectName";
    request.StorageClass = StorageClassEnum.Warm;
    request.ContentType = "image/jpeg";
    request.MetadataDirective = MetadataDirectiveEnum.Replace;
    CopyObjectResponse response = client.CopyObject(request);
    Console.WriteLine("Copy object response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
} 

Copying an Object by Specifying Conditions

When copying an object, you can specify one or more restriction conditions. If the conditions are met, the object will be copied. Otherwise, an exception will be thrown and the copy will fail.

You can set the following conditions:

Parameter

Description

Property in OBS .NET SDK

Copy-Source-If-Modified-Since

Copies the source object if it is changed after the time specified by this parameter; otherwise, an exception is thrown.

CopyObjectRequest.IfModifiedSince

Copy-Source-If-Unmodified-Since

Copies the source object if it is changed before the time specified by this parameter; otherwise, an exception is thrown.

CopyObjectRequest.IfUnmodifiedSince

Copy-Source-If-Match

Copies the source object if its ETag is the same as the one specified by this parameter; otherwise, an exception is thrown.

CopyObjectRequest.IfMatch

Copy-Source-If-None-Match

Copies the source object if its ETag is different from the one specified by this parameter; otherwise, an exception is thrown.

CopyObjectRequest.IfNoneMatch

  • The ETag of the source object is the MD5 check value of the source object.
  • If the object copy request includes IfUnmodifiedSince, IfMatch, IfModifiedSince, or IfNoneMatch, and the specified condition is not met, the copy will fail and an exception will be thrown with HTTP status code 412 Precondition Failed returned.
  • IfModifiedSince and IfNoneMatch can be used together and so do IfUnmodifiedSince and IfMatch.

Sample code:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);

// Set the condition for restricting the copy.
try
{
    CopyObjectRequest request = new CopyObjectRequest();
    request.SourceBucketName = "sourcebucketname";
    request.SourceObjectKey = "sourceobjectname";
    request.BucketName = "destbucketname";
    request.ObjectKey = "destobjectName";

    request.IfModifiedSince = new DateTime(2018, 3, 10, 12, 00, 00);
    CopyObjectResponse response = client.CopyObject(request);
    Console.WriteLine("Copy object response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
} 

Modifying the Object ACL

Sample code:

// Initialize configuration parameters.
ObsConfig config = new ObsConfig();
config.Endpoint = "https://your-endpoint";
// Hard-coded or plaintext AK/SK are risky. For security purposes, encrypt your AK/SK and store them in the configuration file or environment variables. In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, configure environment variables AccessKeyID and SecretAccessKey.
// Obtain an AK/SK pair on the management console. For details, see https://support.huaweicloud.com/intl/en-us/usermanual-ca/ca_01_0003.html.
string accessKey= Environment.GetEnvironmentVariable("AccessKeyID", EnvironmentVariableTarget.Machine);
string secretKey= Environment.GetEnvironmentVariable("SecretAccessKey", EnvironmentVariableTarget.Machine);
// Create an instance of ObsClient.
ObsClient client = new ObsClient(accessKey, secretKey, config);
// Rewrite the object ACL.
try
{
    CopyObjectRequest request = new CopyObjectRequest();
    request.SourceBucketName = "sourcebucketname";
    request.SourceObjectKey = "sourceobjectname";
    request.BucketName = "destbucketname";
    request.ObjectKey = "destobjectName";
    request.CannedAcl = CannedAclEnum.PublicRead;
    CopyObjectResponse response = client.CopyObject(request);
    Console.WriteLine("Copy object response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}