com.prosysopc.ua.server

Class Subscription

java.lang.Object

com.prosysopc.ua.SubscriptionBase

com.prosysopc.ua.server.Subscription

All Implemented Interfaces:

Comparable<SubscriptionBase>

public class Subscription
extends SubscriptionBase

An OPC UA subscription. Subscriptions are used to report Notifications to the Client.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Subscription.PublishTask A task for publishing the data change notifications.

Field Summary

Fields inherited from class com.prosysopc.ua.SubscriptionBase

items, lifetimeCount, maxKeepAliveCount, maxNotificationsPerPublish, priority, publishingEnabled, publishingInterval, updateCount

Constructor Summary

Constructors

Constructor and Description
Subscription(SubscriptionManager subscriptionManager, UnsignedInteger id, Boolean publishingEnabled, Double requestedPublishingInterval, UnsignedInteger requestedLifetimeCount, UnsignedInteger requestedMaxKeepAliveCount, UnsignedInteger maxNotificationsPerPublish, UnsignedByte priority) Create a new subscription.

Method Summary

Modifier and Type	Method and Description
protected void	acknowledge(UnsignedInteger sequenceNumber) Acknowledge that a notification was received by the client.
MonitoredDataItem	addDataItem(ServiceContext serviceContext, NodeId nodeId, UnsignedInteger attributeId, NumericRange indexRange, QualifiedName dataEncoding, MonitoringMode monitoringMode) Add a new monitoring item to the subscription.
MonitoredDataItem	addDataItem(ServiceContext serviceContext, UaNode node, UnsignedInteger attributeId, NumericRange indexRange, QualifiedName dataEncoding, MonitoringMode monitoringMode) Add a new monitoring item to the subscription.
MonitoredEventItem	addEventItem(ServiceContext serviceContext, NodeId nodeId, EventFilter eventFilter, EventFilterResult filterResult) Add a new item to event monitoring.
protected void	addToPublishQueue(long time, boolean needsKeepAlive, boolean checkNotifyTransaction)
void	beginNotify() Begins a Notify change operation.
void	close() Close the subscription.
int	compareTo(SubscriptionBase s)
protected MonitoredDataItem	createMonitoredDataItem(ServiceContext serviceContext, Subscription subscription, UnsignedInteger monitoredItemId, NodeId nodeId, UnsignedInteger attributeId, NumericRange indexRange, MonitoringMode monitoringMode) This can be overridden to use a subtyped MonitoredDataItem in a subtyped Subscription.
protected MonitoredEventItem	createMonitoredEventItem(ServiceContext serviceContext, Subscription subscription, UnsignedInteger monitoredItemId, NodeId nodeId, EventFilter eventFilter, EventFilterResult filterResult) This can be overridden to use a subtyped MonitoredEventItem in a subtyped Subscription.
protected void	enabledChanged() Handles a change in PublishingEnabled.
void	endNotify() Ends a "Notify transaction" started with beginNotify()).
boolean	equals(Object obj)
UnsignedInteger[]	getAvailableSequenceNumbers()
SubscriptionDiagnostics	getDiagnostics()
MonitoredItem	getItem(NodeId nodeId, UnsignedInteger attributeId) Find the item that is listening to the specified node attribute.
int	getMaxNotificationsPerPublish() The maximum number of notifications that the Client wishes to receive in a single Publish response.
protected NotificationMessage	getNextNotificationMessage(Session session)
protected UnsignedInteger	getNextSequenceNumber(boolean isKeepAliveMessage)
protected NotificationMessage	getNotificationMessage(UnsignedInteger retransmitSequenceNumber)
protected BlockingQueue<SubscriptionBase>	getPublishQueue()
Session	getSession()
SubscriptionManager	getSubscriptionManager()
boolean	hasExpired()
int	hashCode()
Boolean	hasMoreNotifications()
protected void	incrementOverflowCount()
protected void	internalClose(boolean removeFromQueue) Close the subscription.
protected void	internalRemoveItem(MonitoredItem item) The actual method that will remove the item from the Subscription.
boolean	isClosed()
protected boolean	isTimeToPublish(long now)
protected void	monitoringModeChanged(MonitoredItem monitoredItem)
protected void	needTrigger(MonitoredItem triggeringItem, boolean isDataChange, boolean isEventChange)
protected void	newEventAvailable(MonitoredEventItem monitoredEventItem)
protected void	newSampleAvailable(MonitoredItem monitoredItem)
protected void	paramChanged() Parameter change "event".
MonitoredItemBase	removeItem(MonitoredItemBase item) Remove an item from the subscription.
MonitoredItemBase	removeItem(UnsignedInteger itemId) Remove an item from the subscription.
protected void	resetKeepAliveCounter()
protected void	resetLastAliveTime()
protected void	setPublishQueue(BlockingQueue<SubscriptionBase> queue, boolean sendInitialValues)
protected static void	setPublishTimeCheckAllowedThresholdMS(int value) Set allowed threshold for publish checks.
protected void	setSession(Session session)
void	start() Close the subscription.
protected void	startPublishing() Starts the publish timer.
protected void	stopPublishing() Stops the publish timer.
protected void	updateDiagnostics()

Methods inherited from class com.prosysopc.ua.SubscriptionBase

addItem, applyUpdates, beginUpdate, endUpdate, getItem, getItem, getItemCount, getItems, getLifetimeCount, getMaxKeepAliveCount, getPriority, getPublishingInterval, getSubscriptionId, getUserData, hasItem, hasItem, hasItem, isPublishingEnabled, setLifetimeCount, setLifetimeCount, setMaxKeepAliveCount, setMaxKeepAliveCount, setMaxNotificationsPerPublish, setMaxNotificationsPerPublish, setPriority, setPriority, setPublishingEnabled, setPublishingInterval, setPublishingInterval, setSubscriptionId, setUserData, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Subscription

public Subscription(SubscriptionManager subscriptionManager,
                    UnsignedInteger id,
                    Boolean publishingEnabled,
                    Double requestedPublishingInterval,
                    UnsignedInteger requestedLifetimeCount,
                    UnsignedInteger requestedMaxKeepAliveCount,
                    UnsignedInteger maxNotificationsPerPublish,
                    UnsignedByte priority)

Create a new subscription.

Parameters:

publishingEnabled -

requestedPublishingInterval -

requestedLifetimeCount -

requestedMaxKeepAliveCount -

maxNotificationsPerPublish -

priority -

Method Detail

setPublishTimeCheckAllowedThresholdMS

protected static void setPublishTimeCheckAllowedThresholdMS(int value)

Set allowed threshold for publish checks. For internal use only!.

Parameters:

value -

addDataItem

public MonitoredDataItem addDataItem(ServiceContext serviceContext,
                                     NodeId nodeId,
                                     UnsignedInteger attributeId,
                                     NumericRange indexRange,
                                     QualifiedName dataEncoding,
                                     MonitoringMode monitoringMode)

Add a new monitoring item to the subscription.

Parameters:

nodeId -

dataEncoding -

indexRange -

attributeId -

monitoringMode -

serviceContext -

addDataItem

public MonitoredDataItem addDataItem(ServiceContext serviceContext,
                                     UaNode node,
                                     UnsignedInteger attributeId,
                                     NumericRange indexRange,
                                     QualifiedName dataEncoding,
                                     MonitoringMode monitoringMode)

Add a new monitoring item to the subscription.

Parameters:

node -

dataEncoding -

indexRange -

attributeId -

monitoringMode -

addEventItem

public MonitoredEventItem addEventItem(ServiceContext serviceContext,
                                       NodeId nodeId,
                                       EventFilter eventFilter,
                                       EventFilterResult filterResult)
                                throws StatusException

Add a new item to event monitoring.

Parameters:

nodeId - the node to monitor

dataEncoding -

eventFilter - the event filter definition.

filterResult -

Returns:

the new monitored item.

Throws:

StatusException

beginNotify

public void beginNotify()

Begins a Notify change operation. Most operations that would cause the Subscription to send Notifications in PublishResponses are suppressed until endNotify() is called (or equivalent number of, in case of nested beginNotify() calls). Note that this is a best-effort "transaction", if it last e.g. long enough that a KeepAlive must be sent, it is ignored.

NOTE! In general this is advanced functionality. One use-case could be if multiple MonitoredDataItem.notifyDataChange(DataValue) should be "synchronized" to the same PublishResponse.

close

public void close()
           throws ServiceException

Close the subscription. Requests the SubscriptionManager to close the subscription.

Throws:

ServiceException - if the SubscriptionManager throws the exception

compareTo

public int compareTo(SubscriptionBase s)

Specified by:

compareTo in interface Comparable<SubscriptionBase>

Overrides:

compareTo in class SubscriptionBase

endNotify

public void endNotify()

Ends a "Notify transaction" started with beginNotify()).

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

getAvailableSequenceNumbers

public UnsignedInteger[] getAvailableSequenceNumbers()

Returns:

array of the sequence numbers of sent, but not acknowledged notification messages

getDiagnostics

public SubscriptionDiagnostics getDiagnostics()

getItem

public MonitoredItem getItem(NodeId nodeId,
                             UnsignedInteger attributeId)

Description copied from class: SubscriptionBase

Find the item that is listening to the specified node attribute. Typically, the Variable nodes are monitored for the Value attribute and Object nodes for the EventNotifier attribute.

Overrides:

getItem in class SubscriptionBase

Parameters:

nodeId - the listened node

attributeId - the attribute

Returns:

the respective monitored item or null, if there is no item that is listening to the specified node attribute

getMaxNotificationsPerPublish

public int getMaxNotificationsPerPublish()

Description copied from class: SubscriptionBase

The maximum number of notifications that the Client wishes to receive in a single Publish response. A value of zero indicates that there is no limit.

Overrides:

getMaxNotificationsPerPublish in class SubscriptionBase

Returns:

the maximum number of notifications in a single publish message

See Also:

SubscriptionBase.setMaxNotificationsPerPublish(long)

getSession

public Session getSession()

getSubscriptionManager

public SubscriptionManager getSubscriptionManager()

Returns:

the subscriptionManager

hasExpired

public boolean hasExpired()

Returns:

true if the subscription timed out because of missing publishRequests

hashCode

public int hashCode()

Overrides:

hashCode in class Object

hasMoreNotifications

public Boolean hasMoreNotifications()

Returns:

isClosed

public boolean isClosed()

Returns:

removeItem

public MonitoredItemBase removeItem(MonitoredItemBase item)
                             throws ServiceException,
                                    StatusException

Description copied from class: SubscriptionBase

Remove an item from the subscription.

Specified by:

removeItem in class SubscriptionBase

Parameters:

item - The item to remove.

Returns:

The item that was removed or null, if it was not in the subscription

Throws:

ServiceException - if the (possible) service call to delete the item from the server fails.

StatusException - if the subscription does not contain the item

removeItem

public MonitoredItemBase removeItem(UnsignedInteger itemId)
                             throws ServiceException,
                                    StatusException

Description copied from class: SubscriptionBase

Remove an item from the subscription.

Overrides:

removeItem in class SubscriptionBase

Parameters:

itemId - The ID of the item to remove. In the client side this should be the ClientHandle, but on server side, the MonitoredItemId is used.

Returns:

The item that was removed or null, if there was no such item.

Throws:

ServiceException - if the service call to delete the item from the server fails.

StatusException - if the delete response from the server is bad

start

public void start()

Close the subscription. No more notifications are sent.

acknowledge

protected void acknowledge(UnsignedInteger sequenceNumber)
                    throws ServiceException

Acknowledge that a notification was received by the client. The notification is then removed from the sentNotifications.

Parameters:

sequenceNumber - the message to acknowledge

Throws:

ServiceException - Bad_SequenceNumberUnknown if the seuqnceNumber is not recognized

addToPublishQueue

protected void addToPublishQueue(long time,
                                 boolean needsKeepAlive,
                                 boolean checkNotifyTransaction)

Parameters:

time -

createMonitoredDataItem

protected MonitoredDataItem createMonitoredDataItem(ServiceContext serviceContext,
                                                    Subscription subscription,
                                                    UnsignedInteger monitoredItemId,
                                                    NodeId nodeId,
                                                    UnsignedInteger attributeId,
                                                    NumericRange indexRange,
                                                    MonitoringMode monitoringMode)

This can be overridden to use a subtyped MonitoredDataItem in a subtyped Subscription.

createMonitoredEventItem

protected MonitoredEventItem createMonitoredEventItem(ServiceContext serviceContext,
                                                      Subscription subscription,
                                                      UnsignedInteger monitoredItemId,
                                                      NodeId nodeId,
                                                      EventFilter eventFilter,
                                                      EventFilterResult filterResult)
                                               throws StatusException

This can be overridden to use a subtyped MonitoredEventItem in a subtyped Subscription.

Throws:

StatusException

enabledChanged

protected void enabledChanged()
                       throws ServiceException

Handles a change in PublishingEnabled.

Overrides:

enabledChanged in class SubscriptionBase

Throws:

ServiceException

getNextNotificationMessage

protected NotificationMessage getNextNotificationMessage(Session session)

Returns:

Throws:

ServiceException

getNextSequenceNumber

protected UnsignedInteger getNextSequenceNumber(boolean isKeepAliveMessage)

getNotificationMessage

protected NotificationMessage getNotificationMessage(UnsignedInteger retransmitSequenceNumber)
                                              throws ServiceException

Parameters:

retransmitSequenceNumber -

Returns:

Throws:

StatusException

ServiceException

getPublishQueue

protected BlockingQueue<SubscriptionBase> getPublishQueue()

incrementOverflowCount

protected void incrementOverflowCount()

internalClose

protected void internalClose(boolean removeFromQueue)

Close the subscription. No more notifications are sent.

internalRemoveItem

protected void internalRemoveItem(MonitoredItem item)
                           throws ServiceException,
                                  StatusException

The actual method that will remove the item from the Subscription. The method is always called by the SubscriptionManager from deleteMonitoredItem. By this way we make sure that the related notifications are always sent from all related Managers.

Parameters:

item -

Throws:

StatusException

ServiceException

isTimeToPublish

protected boolean isTimeToPublish(long now)

Returns:

monitoringModeChanged

protected void monitoringModeChanged(MonitoredItem monitoredItem)

needTrigger

protected void needTrigger(MonitoredItem triggeringItem,
                           boolean isDataChange,
                           boolean isEventChange)

newEventAvailable

protected void newEventAvailable(MonitoredEventItem monitoredEventItem)

Parameters:

monitoredEventItem -

newSampleAvailable

protected void newSampleAvailable(MonitoredItem monitoredItem)

Parameters:

monitoredItem -

value -

paramChanged

protected void paramChanged()
                     throws ServiceException

Parameter change "event".

Overrides:

paramChanged in class SubscriptionBase

Throws:

ServiceException

resetKeepAliveCounter

protected void resetKeepAliveCounter()

resetLastAliveTime

protected void resetLastAliveTime()

setPublishQueue

protected void setPublishQueue(BlockingQueue<SubscriptionBase> queue,
                               boolean sendInitialValues)

Parameters:

queue - the publishQueue to set

sendInitialValues -

setSession

protected void setSession(Session session)

Parameters:

session -

startPublishing

protected void startPublishing()

Starts the publish timer. Use updateTimer normally to start/stop the timer as necessary.

stopPublishing

protected void stopPublishing()

Stops the publish timer. Use updateTimer normally to start/stop the timer as necessary.

updateDiagnostics

protected void updateDiagnostics()