org.eclipse.milo.opcua.sdk.client.subscriptions

Interface ManagedSubscription.StatusListener

Enclosing class:

ManagedSubscription

public static interface ManagedSubscription.StatusListener

A callback that receives status-related notifications for a ManagedSubscription.

Method Summary

Modifier and Type	Method and Description
default void	onNotificationDataLost(ManagedSubscription subscription) Notification data for this subscription was lost because attempts to call the Republish service failed.
default void	onSubscriptionStatusChanged(ManagedSubscription subscription, org.eclipse.milo.opcua.stack.core.types.builtin.StatusCode statusCode) A status change notification for subscription was received.
default void	onSubscriptionTransferFailed(ManagedSubscription subscription, org.eclipse.milo.opcua.stack.core.types.builtin.StatusCode statusCode) A subscription transfer has failed.

Method Detail

onNotificationDataLost

default void onNotificationDataLost(ManagedSubscription subscription)

Notification data for this subscription was lost because attempts to call the Republish service failed.

Some action is required to ensure all the data items belonging to this subscription have a current value. The default implementation asynchronously invokes the the ResendData method on the server with this subscription's id as the argument.

Parameters:

subscription - the ManagedSubscription for which notification data was lost.

onSubscriptionStatusChanged

default void onSubscriptionStatusChanged(ManagedSubscription subscription,
                                         org.eclipse.milo.opcua.stack.core.types.builtin.StatusCode statusCode)

A status change notification for subscription was received.

Generally this happens in 2 scenarios:

1. the subscription has timed out on the server and no longer exists. In this case the statusCode should be StatusCodes.Bad_Timeout. If data and event change notifications for items belonging to this subscription are still desired then the subscription should be re-created.
2. the subscription has been transferred to another session. In this case the statusCode should be StatusCodes.Good_SubscriptionTransferred and no further action is necessary.

Parameters:

subscription - the ManagedSubscription for which a status change notification was received.

statusCode - the StatusCode from the status change notification.

onSubscriptionTransferFailed

default void onSubscriptionTransferFailed(ManagedSubscription subscription,
                                          org.eclipse.milo.opcua.stack.core.types.builtin.StatusCode statusCode)

A subscription transfer has failed.

Upon reconnecting after a connection interruption an OpcUaClient will attempt to resume its previous Session. If this fails a new Session is created and the Subscriptions from the previous Session are transferred to the new one.

This callback is notified when the transfer to the new session has failed and indicates that the subscription and all of its ManagedDataItems and ManagedEventItems will need to be created again.

Parameters:

subscription - the ManagedSubscription for which transfer has failed.

statusCode - the StatusCode for the transfer failure.