Manage data subscriptions-DataHub(DataHub)-阿里云帮助中心

Data subscription

Subscription operations

The subscription feature saves consumption offsets on the server with high availability.

Create a subscription

Note

CreateSubscriptionResult createSubscription(String projectName, String topicName, String comment);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- comment: the description of the subscription.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException
Sample code

public static void createSubscription() {
  try {
      CreateSubscriptionResult createSubscriptionResult = datahubClient.createSubscription(Constant.projectName, Constant.topicName, Constant.subscribtionComment);
      System.out.println("create subscription successful");
      System.out.println(createSubscriptionResult.getSubId());
  } catch (InvalidParameterException e) {
      System.out.println("invalid parameter, please check your parameter");
      System.exit(1);
  } catch (AuthorizationFailureException e) {
      System.out.println("AK error, please check your accessId and accessKey");
      System.exit(1);
  } catch (ResourceNotFoundException e) {
      System.out.println(" project or topic not found,please create project first");
      System.exit(1);
  } catch (DatahubClientException e) {
      System.out.println("other error");
      System.out.println(e);
      System.exit(1);
  }
}

Delete a subscription

Note

DeleteSubscriptionResult deleteSubscription(String projectName, String topicName, String subId);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- subId: the ID of the subscription.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException
Sample code

public static void deleteSubscription() {
  try {
      datahubClient.deleteSubscription(Constant.projectName, Constant.topicName, subId);
      System.out.println("delete subscription successful");
  } catch (InvalidParameterException e) {
      System.out.println("invalid parameter, please check your parameter");
      System.exit(1);
  } catch (AuthorizationFailureException e) {
      System.out.println("AK error, please check your accessId and accessKey");
      System.exit(1);
  } catch (ResourceNotFoundException e) {
      System.out.println(" project or topic or subId not found,delete successful");
  } catch (DatahubClientException e) {
      System.out.println("other error");
      System.out.println(e);
      System.exit(1);
  }
}

Update a subscription

Only the description of a subscription can be updated.

Note

UpdateSubscriptionResult updateSubscription(String projectName, String topicName, String subId, String comment);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- subId: the ID of the subscription.
- comment: the new description for the subscription.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException
Sample code

Query subscriptions

The pageNum and pageSize parameters of the listSubscription method specify the range of subscriptions to query. For example, if pageNum is set to 1 and pageSize to 10, the first 10 subscriptions are returned. If pageNum is set to 2 and pageSize to 5, the 6th to 10th subscriptions are returned.

Note

ListSubscriptionResult listSubscription(String projectName, String topicName, int pageNum, int pageSize);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- pageNum: the number of the page to return.
- pageSize: the number of subscriptions to return on each page.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException
Sample code
Sample code

public static void listSubscription() {
    try {
        ListSubscriptionResult listSubscriptionResult = datahubClient.listSubscription(Constant.projectName, Constant.topicName, Constant.pageNum, Constant.pageSize);
        if (listSubscriptionResult.getSubscriptions().size() > 0) {
            System.out.println(listSubscriptionResult.getTotalCount());
            System.out.println(listSubscriptionResult.getSubscriptions().size());
            for (SubscriptionEntry entry : listSubscriptionResult.getSubscriptions()) {
                System.out.println(entry.getSubId() + "\t"
                        + entry.getState() + "\t"
                        + entry.getType() + "\t"
                        + entry.getComment());
            }
        }
    } catch (InvalidParameterException e) {
        System.out.println("invalid parameter, please check your parameter");
        System.exit(1);
    } catch (AuthorizationFailureException e) {
        System.out.println("AK error, please check your accessId and accessKey");
        System.exit(1);
    } catch (ResourceNotFoundException e) {
        System.out.println(" project or topic not found,delete successful");
        System.exit(1);
    } catch (DatahubClientException e) {
        System.out.println("other error");
        System.out.println(e);
        System.exit(1);
    }
}

Query a subscription

Note

GetSubscriptionResult getSubscription(String projectName, String topicName, String subId);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- subId: the ID of the subscription.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException

public static void getSubscription() {
    try {
        GetSubscriptionResult getSubscriptionResult = datahubClient.getSubscription(Constant.projectName, Constant.topicName, subId);
        System.out.println(getSubscriptionResult.getSubId() + "\t"
                + getSubscriptionResult.getState() + "\t"
                + getSubscriptionResult.getType() + "\t"
                + getSubscriptionResult.getComment());
    } catch (InvalidParameterException e) {
        System.out.println("invalid parameter, please check your parameter");
        System.exit(1);
    } catch (AuthorizationFailureException e) {
        System.out.println("AK error, please check your accessId and accessKey");
        System.exit(1);
    } catch (ResourceNotFoundException e) {
        System.out.println(" project or topic or subscription not found,delete successful");
        System.exit(1);
    } catch (DatahubClientException e) {
        System.out.println("other error");
        System.out.println(e);
        System.exit(1);
    }
}

Update the status of a subscription

A subscription can be in the OFFLINE or ONLINE state.

Note

UpdateSubscriptionStateResult updateSubscriptionState(String projectName, String topicName, String subId, SubscriptionState state);

Parameters
- projectName: the name of the project.
- topicName: the name of the topic.
- subId: the ID of the subscription.
- state: the target state of the subscription.
Exceptions
- DatahubClientException
- InvalidParameterException
- AuthorizationFailureException
- ResourceNotFoundException
Sample code

public static void updateSubscriptionState() {
    try {
        datahubClient.updateSubscriptionState(Constant.projectName, Constant.topicName, subId, SubscriptionState.ONLINE);
        System.out.println("update subscription state successful");
    } catch (InvalidParameterException e) {
        System.out.println("invalid parameter, please check your parameter");
        System.exit(1);
    } catch (AuthorizationFailureException e) {
        System.out.println("AK error, please check your accessId and accessKey");
        System.exit(1);
    } catch (ResourceNotFoundException e) {
        System.out.println(" project or topic not found,delete successful");
        System.exit(1);
    } catch (DatahubClientException e) {
        System.out.println("other error");
        System.out.println(e);
        System.exit(1);
    }
}