A bucket is the globally unique namespace in TOS, functioning as a data container for storing object data. When the requested object data does not exist in the bucket, TOS returns a 404 error by default. However, if you configure the bucket's back-to-origin rule and enter the correct object data address, TOS will obtain data from the origin site using the back-to-origin rule. TOS supports both mirror-based (mirroring) and redirect-based (redirection) back-to-origin, enabling you to meet requirements such as hot data migration and redirection of specific requests.

This article describes how to manage bucket back-to-origin rules using the TOS Java SDK.

Configure mirroring rules

You can set the mirror back rule for a specified bucket through the putBucketMirrorBack interface of the TOS Java SDK.

Sample code

The following code demonstrates how to configure the mirroring rule for a specified bucket.

import com.volcengine.tos.TOSV2;​
import com.volcengine.tos.TOSV2ClientBuilder;​
import com.volcengine.tos.TosClientException;​
import com.volcengine.tos.TosServerException;​
import com.volcengine.tos.comm.common.RedirectType;​
import com.volcengine.tos.model.bucket.*;​
​
import java.util.ArrayList;​
import java.util.List;​
​
public class PutBucketMirrorBackExample {​
    public static void main(String[] args) {​
        String endpoint = "your endpoint";​
        String region = "your region";​
        String accessKey = System.getenv("TOS_ACCESS_KEY");​
        String secretKey = System.getenv("TOS_SECRET_KEY");​
​
        String bucketName = "your bucket name";​
​
        TOSV2 tos = new TOSV2ClientBuilder().build(region, endpoint, accessKey, secretKey);​
​
        try{​
            Condition condition = new Condition().setHttpCode(404);​
            List<String> passList = new ArrayList<>();​
            passList.add("pass_header1");​
            passList.add("pass_header2");​
            List<String> removeList = new ArrayList<>();​
            removeList.add("remove_header1");​
            removeList.add("remove_header2");​
            MirrorHeader mirrorHeader = new MirrorHeader().setPassAll(true)​
                    .setPass(passList).setRemove(removeList);​
​
            List<String> primary = new ArrayList<>();​
            primary.add("http://www.volcengine.com/obj/tostest/1");​
            List<String> follower = new ArrayList<>();​
            follower.add("http://www.volcengine.com/obj/tostest/2");​
            SourceEndpoint sourceEndpoint = new SourceEndpoint().setPrimary(primary).setFollower(follower);​
            PublicSource publicSource = new PublicSource().setSourceEndpoint(sourceEndpoint);​
            Redirect redirect = new Redirect()​
                    .setRedirectType(RedirectType.REDIRECT_MIRROR)​
                    .setFetchSourceOnRedirect(true)​
                    .setPassQuery(true)​
                    .setFollowRedirect(true)​
                    .setMirrorHeader(mirrorHeader)​
                    .setPublicSource(publicSource);​
            MirrorBackRule rule = new MirrorBackRule().setId("1").setCondition(condition).setRedirect(redirect);​
            List<MirrorBackRule> rules = new ArrayList<>();​
            rules.add(rule);​
            PutBucketMirrorBackInput input = new PutBucketMirrorBackInput().setBucket(bucketName).setRules(rules);​
            PutBucketMirrorBackOutput output = tos.putBucketMirrorBack(input);​
            System.out.println("putBucketMirrorBack succeed");​
        } catch (TosClientException e) {​
            System.out.println("putBucketMirrorBack failed");​
            System.out.println("Message: " + e.getMessage());​
            if (e.getCause() != null) {​
                e.getCause().printStackTrace();​
            }​
        } catch (TosServerException e) {​
            System.out.println("putBucketMirrorBack failed");​
            System.out.println("StatusCode: " + e.getStatusCode());​
            System.out.println("Code: " + e.getCode());​
            System.out.println("Message: " + e.getMessage());​
            System.out.println("RequestID: " + e.getRequestID());​
        } catch (Throwable t) {​
            System.out.println("putBucketMirrorBack failed");​
            System.out.println("unexpected exception, message: " + t.getMessage());​
        }​
    }​
}​

Retrieve mirroring rules

You can use the getBucketMirrorBack interface of the TOS Java SDK to obtain the current mirroring rules configured for the specified bucket.

Sample code

The following code demonstrates how to retrieve the mirroring rules for a specified bucket.

Delete mirroring rules

You can use the deleteBucketMirrorBack interface of the TOS Java SDK to delete the currently configured mirroring rule for a specified bucket.

Sample code

The following code demonstrates how to delete the mirroring rule for a specified bucket.

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