Listing Versioning Objects

You can call ObsClient.ListVersions to list versioning objects.

The following table describes the parameters involved in this API.

Parameter	Description	Property in OBS .NET SDK
BucketName	Bucket name	ListVersionsRequest.BucketName
Prefix	Name prefix that the objects to be listed must contain	ListVersionsRequest.Prefix
KeyMarker	Object name to start with when listing versioning objects in a bucket. All versioning objects following this parameter are listed in the lexicographical order.	ListVersionsRequest.KeyMarker
MaxKeys	Maximum number of listed versioning objects. The value ranges from 1 to 1000. If the specified value exceeds 1000, only 1,000 versioning objects are returned by default.	ListVersionsRequest.MaxKeys
Delimiter	Character used to group object names. If the object name contains the Delimiter parameter, the character string from the first character to the first delimiter in the object name is grouped under a single result element, CommonPrefix. (If a prefix is specified in the request, the prefix must be removed from the object name.)	ListVersionsRequest.Delimiter
VersionIdMarker	Object name to start with when listing versioning objects in a bucket. All versioning objects are listed in the lexicographical order by object name and version ID. This parameter must be used together with KeyMarker.	ListVersionsRequest.VersionIdMarker

If the value of VersionIdMarker is not a version ID specified by KeyMarker, VersionIdMarker is ineffective.
The returned result of ObsClient.ListVersions includes the versioning objects and delete markers.

Listing Versioning Objects in Simple Mode

The following sample code shows how to list versioning objects in simple mode. A maximum of 1000 versioning objects can be returned.

// 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/eu/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);
//List versioning objects.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Information about a maximum of 1000 versioning objects can be listed each time. If a bucket contains more than 1000 objects and ListVersionsResponse.IsTruncated is true in the returned result, not all versioning objects are listed. In such cases, you can use ListVersionsResponse.NextKeyMarker and ListVersionsResponse.NextVersionIdMarker to obtain the start position for next listing.

Listing Versioning Objects by Specifying the Number

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/eu/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);
//List versioning objects by specifying the number.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing Versioning Objects by Specifying a Prefix

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/eu/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);
//List versioning objects by specifying a prefix.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    request.Prefix = "prefix";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing Versioning Objects by Specifying the Start Position

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/eu/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);
//Specify the start position for listing.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    request.Prefix = "prefix";
    request.KeyMarker = "keyMarker";
    ListVersionsResponse response = client.ListVersions(request);
    foreach (ObsObjectVersion objectVersion in response.Versions)
    {
        Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
        Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
    }
    Console.WriteLine("List versions response: {0}", response.StatusCode);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing All Versioning Objects in Paging 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/eu/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);
//List all versioning objects in paging mode.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 100;
    ListVersionsResponse response;
    do
    {
        response = client.ListVersions(request);
        Console.WriteLine("List versions response: {0}", response.StatusCode);
        foreach (ObsObjectVersion objectVersion in response.Versions)
        {
            Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
            Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
        }
        request.KeyMarker = response.NextKeyMarker;
        request.VersionIdMarker = response.NextVersionIdMarker;
    }
    while (response.IsTruncated);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}

Listing All Versioning Objects in a Folder

There is no folder concept in OBS. All elements in buckets are objects. Folders are actually objects whose sizes are 0 and whose names end with a slash (/). When you set a folder name as the prefix, objects in this folder will be listed. Sample code is as follows:

// 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/eu/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);
//List all versioning objects in paging mode.
try
{
    ListVersionsRequest request = new ListVersionsRequest();
    request.BucketName = "bucketname";
    request.MaxKeys = 1000;
    // Set the prefix to dir/.
    request.Prefix = "dir/";
    ListVersionsResponse response;
    do
    {
        response = client.ListVersions(request);
        Console.WriteLine("List versions response: {0}", response.StatusCode);
        foreach (ObsObjectVersion objectVersion in response.Versions)
        {
            Console.WriteLine("Key: {0}", objectVersion.ObjectKey);
            Console.WriteLine("VersionId: {0}", objectVersion.VersionId);
        }
        request.KeyMarker = response.NextKeyMarker;
        request.VersionIdMarker = response.NextVersionIdMarker;
    }
    while (response.IsTruncated);
}
catch (ObsException ex)
{
    Console.WriteLine("ErrorCode: {0}", ex.ErrorCode);
    Console.WriteLine("ErrorMessage: {0}", ex.ErrorMessage);
}