public interface SmartDataProvider extends DataProvider
DataProvider
,
ItemEventListener
ADD_COMMAND, COMMAND_FIELD, DELETE_COMMAND, KEY_FIELD, UPDATE_COMMAND
Modifier and Type | Method and Description |
---|---|
void |
subscribe(java.lang.String itemName,
boolean needsIterator)
Inherited by the base interface DataProvider but never called in this
case, because the extended version will always be called in its place.
|
void |
subscribe(java.lang.String itemName,
java.lang.Object itemHandle,
boolean needsIterator)
Called by Lightstreamer Kernel to request data for an Item.
|
init, isSnapshotAvailable, setListener, unsubscribe
void subscribe(java.lang.String itemName, java.lang.Object itemHandle, boolean needsIterator) throws SubscriptionException, FailureException
DataProvider.subscribe(String, boolean)
.itemName
- Name of an Item.itemHandle
- Object to be used to identify the item in update
calls. Lightstreamer Kernel always uses different handles across
subsequent subscriptions of the same item.needsIterator
- Signals that the getNames method will be called
on the ItemEvents received for this Item. If this flag is set to false,
the ItemEvent objects sent for this Item need not implement the method.SubscriptionException
- if the request cannot be satisfied.
A failed subscription is not notified to the clients; it just causes
the clients not to receive data. Upon a failed subscription, the
related DataProvider.unsubscribe(String)
call will not be issued.FailureException
- if the method execution has caused a severe
problem that can compromise future operation of the Data Adapter.
This causes the whole Server to exit, so that an external recovery
mechanism may come into action.ItemEventListener
,
ItemEvent
,
DataProvider.subscribe(java.lang.String, boolean)
void subscribe(java.lang.String itemName, boolean needsIterator) throws SubscriptionException, FailureException
subscribe
in interface DataProvider
itemName
- Not to be used in this context.needsIterator
- Not to be used in this context.SubscriptionException
- Can always be thrown in this context.FailureException
- Not to be thrown in this context.ItemEventListener
,
ItemEvent