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Object Storage Service:Restore objects

Last Updated:Sep 11, 2023

In a versioning-enabled Object Storage Service (OSS) bucket, the storage classes of different versions of an object can be different. By default, when you call the RestoreObject operation to restore an object, the current version of the object is restored. You can specify a version ID in the request to restore the specified version of an object.

Usage notes

  • In this topic, the public endpoint of the China (Hangzhou) region is used. If you want to access OSS by using other Alibaba Cloud services in the same region as OSS, use an internal endpoint. For more information about the regions and endpoints supported by OSS, see Regions and endpoints.

  • In this topic, access credentials are obtained from environment variables. For more information about how to configure access credentials, see Configure access credentials.

  • In this topic, an OSSClient instance is created by using an OSS endpoint. If you want to create an OSSClient instance by using custom domain names or Security Token Service (STS), see Create an OSSClient instance.

  • To restore an object, you must have the oss:RestoreObject permission. For more information, see Common examples of RAM policies.

Examples

The following sample code provides an example on how to restore an object:

import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // In this example, the endpoint of the China (Hangzhou) region is used. Specify your actual endpoint. 
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured. 
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the bucket. Example: examplebucket. 
        String bucketName = "examplebucket";
        // Specify the full path of the object. Do not include the bucket name in the full path. 
        String objectName = "exampledir/object";
        // Specify the version ID of the Archive object that you want to restore. 
        String versionId = "CAEQMxiBgICAof2D0BYiIDJhMGE3N2M1YTI1NDQzOGY5NTkyNTI3MGYyMzJm****";

        // Create an OSSClient instance. 
        OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);

        try {
            // Query part of metadata of the specified version of the object. 
            GenericRequest getObjectMetadataRequest = new GenericRequest(bucketName,objectName, versionId);
            ObjectMetadata objectMetadata = ossClient.getObjectMetadata(getObjectMetadataRequest);

            // Check whether the specified version of the object is an Archive object. 
            StorageClass storageClass = objectMetadata.getObjectStorageClass();
            System.out.println("object storage class:" + objectMetadata.getObjectStorageClass());
            if (storageClass == StorageClass.Archive) {
                // Restore the object. 
                GenericRequest genericRequest = new GenericRequest(bucketName, objectName, versionId);
                RestoreObjectResult restoreObjectResult = ossClient.restoreObject(genericRequest);
                System.out.println("restor versionid: " + restoreObjectResult.getVersionId());

                // Specify the time to wait for the object to be restored. 
                do {
                    Thread.sleep(1000);
                    objectMetadata = ossClient.getObjectMetadata(getObjectMetadataRequest);
                    System.out.println("is competed:" + objectMetadata.isRestoreCompleted());
                } while (!objectMetadata.isRestoreCompleted());
            }

            // Specify the version ID of the object that you want to restore. 
            GetObjectRequest getObjectRequest = new GetObjectRequest(bucketName, objectName);
            getObjectRequest.setVersionId(versionId);
            OSSObject ossObject = ossClient.getObject(getObjectRequest);
            ossObject.getObjectContent().close();
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

References

For more information about the API operation that you can call to restore an object, see RestoreObject.