Manage object ACLs (OSS SDK for Java 1.0)

Usage notes

• In this topic, the public endpoint of the China (Hangzhou) region is used. To access OSS from other Alibaba Cloud services in the same region, use an internal endpoint. For details about supported regions and endpoints, see Regions and Endpoints.

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

• This topic demonstrates creating an OSSClient instance with an OSS endpoint. For alternative configurations, such as using a custom domain or authenticating with credentials from Security Token Service (STS), see Client configuration.

• To set the ACL for an object, you must have the oss:PutObjectAcl permission. To retrieve the ACL of an object, you must have the oss:GetObjectAcl permission. For more information, see Grant a custom policy.

Set the ACL of an object

By default, the PutObjectACL operation sets the ACL of the current version of an object. If the current version is a delete marker, OSS returns 404 Not Found. You can specify a version ID to set the ACL of a specific version.

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // The endpoint of the China (Hangzhou) region is used in this example. Specify your actual endpoint.
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Get access credentials from environment variables. Before you run this 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 bucket name. Example: examplebucket.
        String bucketName = "examplebucket";
        // Specify the full path of the object. The full path cannot contain the bucket name.
        String objectName = "exampledir/object";
        // Specify the version ID of the object.
        String versionId = "CAEQMxiBgICAof2D0BYiIDJhMGE3N2M1YTI1NDQzOGY5NTkyNTI3MGYyMzJm****";
        // Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance.
        // Call the shutdown method to release resources when the OSSClient instance is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Create a SetObjectAclRequest object. In this example, the ACL of the object is set to public-read.
            SetObjectAclRequest setObjectAclRequest = new SetObjectAclRequest(bucketName, objectName,
                    versionId, CannedAccessControlList.PublicRead);

            // Set the ACL of the object with the specified version ID.
            ossClient.setObjectAcl(setObjectAclRequest);
        } 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();
            }
        }
    }
}

Get the ACL of an object

By default, the GetObjectACL operation retrieves the ACL of the current version of an object. If the current version is a delete marker, OSS returns 404 Not Found. You can specify a version ID to retrieve the ACL of a specific version.

The following sample code retrieves the ACL of an object:

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.*;

public class Demo {
    public static void main(String[] args) throws Exception {
        // The endpoint of the China (Hangzhou) region is used in this example. Specify your actual endpoint.
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Get access credentials from environment variables. Before you run this 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 bucket name. Example: examplebucket.
        String bucketName = "examplebucket";
        // Specify the full path of the object. The full path cannot contain the bucket name.
        String objectName = "exampledir/object";
        // Specify the version ID of the object.
        String versionId = "CAEQMxiBgICAof2D0BYiIDJhMGE3N2M1YTI1NDQzOGY5NTkyNTI3MGYyMzJm****";
        // Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance.
        // Call the shutdown method to release resources when the OSSClient instance is no longer in use.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            // Get the ACL of the object.
            GenericRequest genericRequest = new GenericRequest(bucketName, objectName, versionId);
            ObjectAcl objectAcl = ossClient.getObjectAcl(genericRequest);
            System.out.println("get object acl: " + objectAcl.getPermission().toString());
            System.out.println("object versionid: " + objectAcl.getVersionId());
        } 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 setting object ACLs, see PutObjectACL.

• For more information about retrieving object ACLs, see GetObjectACL.