W
- type of windowpublic static final class ElementTriggers.EveryElement<W extends Window> extends Trigger<W>
Trigger
that triggers on every element.Trigger.OnMergeContext, Trigger.TriggerContext
Constructor and Description |
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EveryElement() |
Modifier and Type | Method and Description |
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boolean |
canMerge()
Returns true if this trigger supports merging of trigger state and can therefore.
|
void |
clear(W window)
Clears any state that the trigger might still hold for the given window.
|
boolean |
onElement(Object element,
long timestamp,
W window)
Called for every element that gets added to a pane.
|
boolean |
onEventTime(long time,
W window)
Called when an event-time timer that was set using the trigger context fires.
|
void |
onMerge(W window,
Trigger.OnMergeContext mergeContext)
Called when several windows have been merged into one window by the
WindowAssigner . |
boolean |
onProcessingTime(long time,
W window)
Called when a processing-time timer that was set using the trigger context fires.
|
void |
open(Trigger.TriggerContext ctx)
Initialization method for the trigger.
|
String |
toString() |
public void open(Trigger.TriggerContext ctx) throws Exception
Trigger
public boolean onElement(Object element, long timestamp, W window) throws Exception
Trigger
public boolean onProcessingTime(long time, W window) throws Exception
Trigger
Note: This method is not called in case the window does not contain any elements. Thus, if
you return PURGE
from a trigger method and you expect to do cleanup in a future
invocation of a timer callback it might be wise to clean any state that you would clean in
the timer callback.
onProcessingTime
in class Trigger<W extends Window>
time
- The timestamp at which the timer fired.window
- The window for which the timer fired.Exception
public boolean onEventTime(long time, W window) throws Exception
Trigger
Note: This method is not called in case the window does not contain any elements. Thus, if
you return PURGE
from a trigger method and you expect to do cleanup in a future
invocation of a timer callback it might be wise to clean any state that you would clean in
the timer callback.
onEventTime
in class Trigger<W extends Window>
time
- The timestamp at which the timer fired.window
- The window for which the timer fired.Exception
public void clear(W window) throws Exception
Trigger
Trigger.TriggerContext.registerEventTimeTimer(long)
and
Trigger.TriggerContext.registerProcessingTimeTimer(long)
should be deleted here as well as
state acquired using TriggerContext#getPartitionedState(StateDescriptor)
.public boolean canMerge()
Trigger
If this returns true
you must properly implement Trigger.onMerge(Window,
OnMergeContext)
public void onMerge(W window, Trigger.OnMergeContext mergeContext) throws Exception
Trigger
WindowAssigner
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