Listing Versioning Objects

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.

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

ListVersionsResult result = obsClient.listVersions("bucketname");

for(VersionOrDeleteMarker v : result.getVersions()){
    Log.i("ListVersions", "\t" + v.getKey());
    Log.i("ListVersions","\t" + v.getOwner());
    Log.i("ListVersions","\t" + v.isDeleteMarker());
}

• A maximum of 1000 versioning objects can be listed each time. If a bucket contains more than 1000 objects and ListVersionsResult.isTruncated is true in the returned result, not all versioning objects are listed. In such cases, you can use ListVersionsResult.getNextKeyMarker and ListVersionsResult.getNextVersionIdMarker to obtain the start position for next listing.
• If you want to obtain all versioning objects in a specified bucket, you can use the paging mode for listing objects.

Listing Versioning Objects by Specifying the Number

Sample code:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

ListVersionsResult result = obsClient.listVersions("bucketname", 100);
for(VersionOrDeleteMarker v : result.getVersions()){
    Log.i("ListVersions","\t" + v.getKey());
    Log.i("ListVersions","\t" + v.getOwner());
    Log.i("ListVersions","\t" + v.isDeleteMarker());
}

Listing Versioning Objects by Specifying a Prefix

Sample code:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

// List 100 objects whose name prefix is prefix.
ListVersionsRequest request = new ListVersionsRequest ("bucketname", 100);
request.setPrefix("prefix");
ListVersionsResult result = obsClient.listVersions(request);
for(VersionOrDeleteMarker v : result.getVersions()){
    Log.i("ListVersions","\t" + v.getKey());
    Log.i("ListVersions","\t" + v.getOwner());
    Log.i("ListVersions","\t" + v.isDeleteMarker());
}

Listing Versioning Objects by Specifying the Start Position

Sample code:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

// List 100 versioning objects whose names following test in lexicographic order.
ListVersionsRequest request = new ListVersionsRequest ("bucketname", 100);
request.setKeyMarker("test");
ListVersionsResult result = obsClient.listVersions(request);

for(VersionOrDeleteMarker v : result.getVersions()){
    Log.i("ListVersions","\t" + v.getKey());
    Log.i("ListVersions","\t" + v.getOwner());
    Log.i("ListVersions","\t" + v.isDeleteMarker());
}

Listing All Versioning Objects in Paging Mode

Sample code:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";

// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

ListVersionsResult result;
ListVersionsRequest request = new ListVersionsRequest ("bucketname", 100);
do{
    result = obsClient.listVersions(request);
    for(VersionOrDeleteMarker v : result.getVersions()){
        Log.i("ListVersions","\t" + v.getKey());
        Log.i("ListVersions","\t" + v.getOwner());
        Log.i("ListVersions","\t" + v.isDeleteMarker());
    }
    request.setKeyMarker(result.getNextKeyMarker());
    request.setVersionIdMarker(result.getNextVersionIdMarker());
}while(result.isTruncated());

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:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);

ListVersionsResult result;
ListVersionsRequest request = new ListVersionsRequest ("bucketname", 100);
// Set the prefix of objects in the folder to dir/.
request.setPrefix("dir/");
do{
    result = obsClient.listVersions(request);
    for(VersionOrDeleteMarker v : result.getVersions()){
        Log.i("ListVersions","\t" + v.getKey());
        Log.i("ListVersions","\t" + v.getOwner());
        Log.i("ListVersions","\t" + v.isDeleteMarker());
    }
    request.setKeyMarker(result.getNextKeyMarker());
    request.setVersionIdMarker(result.getNextVersionIdMarker());
}while(result.isTruncated());

Listing All Versioning Objects According to Folders in a Bucket

Sample code:

// 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 ACCESS_KEY_ID and SECRET_ACCESS_KEY_ID.
// 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 ak = System.getenv("ACCESS_KEY_ID");
String sk = System.getenv("SECRET_ACCESS_KEY_ID");
String endPoint = "https://your-endpoint";
// Create an instance of ObsClient.
ObsClient obsClient = new ObsClient(ak, sk, endPoint);
ListVersionsRequest request = new ListVersionsRequest ("bucketname", 1000);
request.setDelimiter("/");
ListVersionsResult result = obsClient.listVersions(request);
Log.i("ListVersions", "Objects in the root directory:");
for(VersionOrDeleteMarker v : result.getVersions()){
    Log.i("ListVersions","\t" + v.getKey());
    Log.i("ListVersions","\t" + v.getOwner());
    Log.i("ListVersions","\t" + v.isDeleteMarker());
}

listVersionsByPrefix(obsClient, result);

The following is the sample code of the listVersionsByPrefix function, which is used to recursively list objects in sub-folders.

static void listVersionsByPrefix(ObsClient obsClient, ListVersionsResult result) throws ObsException{
    for(String prefix : result.getCommonPrefixes()){
         Log.i("ListVersions", "Objects in folder [" + prefix + "]:");
         ListVersionsRequest request = new ListVersionsRequest ("bucketname", 1000);
         request.setDelimiter("/");
         request.setPrefix(prefix)
         result = obsClient.listVersions(request);
         for(VersionOrDeleteMarker v : result.getVersions()){
             Log.i("ListVersions","\t" + v.getKey());
             Log.i("ListVersions","\t" + v.getOwner());
             Log.i("ListVersions","\t" + v.isDeleteMarker());
         }
         listVersionsByPrefix(obsClient, result);
     }
}

• The previous sample code does not include scenarios where the number of objects in a folder exceeds 1000.
• Because objects and sub-folders in a folder are to be listed and all the objects end with a slash (/), delimiter is always a slash (/).
• In the returned result of each recursion, ListVersionsResult.getVersions includes the versioning objects in the folder and ListVersionsResult.getCommonPrefixes includes the sub-folders in the folder.