Package com.streambase.liveview.client
Interface QueryListener
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- All Superinterfaces:
EventListener
- All Known Implementing Classes:
AbstractBatchedQueryListener
,AbstractQueryListener
,CompositeQueryListener
,DeleteQueryListener
,LiveResult
,QueryListenerWrapper
,SnapshotQueryListener
public interface QueryListener extends EventListener
A query listener interface must be provided when registering a query. The server will make call backs to this interface with query events. If you are only interested in a subset of events consider using theAbstractQueryListener
. All tuple events betweensnapshotBegin(BeginSnapshotEvent)
andsnapshotEnd(EndSnapshotEvent)
aretupleAdded(TupleAddedEvent)
events. If theLiveViewQueryType
of the query is SNAPSHOT_AND_CONTINUOUS, then the QueryListener after thesnapshotEnd(EndSnapshotEvent)
can receive any number oftupleAdded(TupleAddedEvent)
,tupleUpdated(TupleUpdatedEvent)
, andtupleRemoved(TupleRemovedEvent)
, in any order. It is also possible that the query results will need to be reset, in which case the QueryListener might receive a newsnapshotBegin(BeginSnapshotEvent)
. This signals that all previous data should be discarded, and the entire process will start fresh. For example, if the query was made through aLiveViewMultiConnection
, and the server that was servicing the query has gone down, and a new server has since picked the connection back up, thesnapshotBegin(BeginSnapshotEvent)
will signal the beginning of a new result set coming from the new server. At any point the QueryListener might receive aexceptionRaised(QueryExceptionEvent)
, if some unrecoverable failure has happened. In that case, the query will be closed and no more TupleEvents will happen. IfsnapshotEnd(EndSnapshotEvent)
has not yet been called, it won't be. The exception will be the final callback made to the QueryListener. Note that callbacks should return quickly. In some situations, long running callbacks can trigger heartbeat failures and/or other connection problems, particularly in the face of high data rates.
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Method Summary
All Methods Instance Methods Abstract Methods Default Methods Modifier and Type Method Description default void
aggMarkBegin(BeginAggMarkEvent event)
Event to indicate that the set of aggregation results may be changing so some results may be from an older generation while other may be from a newer one.default void
aggMarkEnd(EndAggMarkEvent event)
Event to indicate that the set of aggregation results since the last aggMarkBegin event are now consistent and will not change until the next aggMarkBegin.void
deleteBegin(BeginDeleteEvent event)
Event to indicate the start of delete query.void
deleteEnd(EndDeleteEvent event)
Event to indicate the delete query is complete.void
exceptionRaised(QueryExceptionEvent event)
Event when an exception occurs during the query.void
queryClosed(QueryClosedEvent event)
Event when a query being listened to is closed.void
snapshotBegin(BeginSnapshotEvent event)
Event to indicate the start of the result snapshot.void
snapshotEnd(EndSnapshotEvent event)
Event to indicate the query snapshot is complete.void
tupleAdded(TupleAddedEvent event)
Event when a new tuple is added to the result.void
tupleRemoved(TupleRemovedEvent event)
Event when an existing tuple is removed from the result.void
tupleUpdated(TupleUpdatedEvent event)
Event when an existing tuple in the result is updated.
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Method Detail
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tupleAdded
void tupleAdded(TupleAddedEvent event)
Event when a new tuple is added to the result.- Parameters:
event
- add event
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tupleUpdated
void tupleUpdated(TupleUpdatedEvent event)
Event when an existing tuple in the result is updated.- Parameters:
event
- update event
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tupleRemoved
void tupleRemoved(TupleRemovedEvent event)
Event when an existing tuple is removed from the result.- Parameters:
event
- remove event
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snapshotBegin
void snapshotBegin(BeginSnapshotEvent event)
Event to indicate the start of the result snapshot. This is the first method called when a query starts returning results, but this method is also called to indicate a reset (a complete restart of the query.)- Parameters:
event
- snapshot begin
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snapshotEnd
void snapshotEnd(EndSnapshotEvent event)
Event to indicate the query snapshot is complete.- Parameters:
event
- snapshot end
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deleteBegin
void deleteBegin(BeginDeleteEvent event)
Event to indicate the start of delete query.- Parameters:
event
- delete begin- Since:
- 1.5.2
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deleteEnd
void deleteEnd(EndDeleteEvent event)
Event to indicate the delete query is complete.- Parameters:
event
- delete end- Since:
- 1.5.2
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aggMarkEnd
default void aggMarkEnd(EndAggMarkEvent event)
Event to indicate that the set of aggregation results since the last aggMarkBegin event are now consistent and will not change until the next aggMarkBegin.- Parameters:
event
- theEndAggMarkEvent
- Since:
- 7.7.4
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aggMarkBegin
default void aggMarkBegin(BeginAggMarkEvent event)
Event to indicate that the set of aggregation results may be changing so some results may be from an older generation while other may be from a newer one.- Parameters:
event
- theBeginAggMarkEvent
- Since:
- 7.7.4
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exceptionRaised
void exceptionRaised(QueryExceptionEvent event)
Event when an exception occurs during the query. Since 1.3, reaching the row limit is considered an exception.- Parameters:
event
- exception event- Since:
- 1.3 - this method will be invoked when the query row limit is reached (earlier versions would simply end streaming results)
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queryClosed
void queryClosed(QueryClosedEvent event)
Event when a query being listened to is closed.- Parameters:
event
- query closed event
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