org.apache.flink.streaming.api.windowing.triggers

Class EventTimeTrigger

java.lang.Object

org.apache.flink.streaming.api.windowing.triggers.EventTimeTrigger

All Implemented Interfaces:

Serializable, Trigger<Object,TimeWindow>

public class EventTimeTrigger
extends Object
implements Trigger<Object,TimeWindow>

A Trigger that fires once the watermark passes the end of the window to which a pane belongs.

See Also:

Watermark, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.streaming.api.windowing.triggers.Trigger

Trigger.TriggerContext, Trigger.TriggerResult

Method Summary

Methods

Modifier and Type	Method and Description
static EventTimeTrigger	create() Creates an event-time trigger that fires once the watermark passes the end of the window.
Trigger.TriggerResult	onElement(Object element, long timestamp, TimeWindow window, Trigger.TriggerContext ctx) Called for every element that gets added to a pane.
Trigger.TriggerResult	onEventTime(long time, TimeWindow window, Trigger.TriggerContext ctx) Called when an event-time timer that was set using the trigger context fires.
Trigger.TriggerResult	onProcessingTime(long time, TimeWindow window, Trigger.TriggerContext ctx) Called when a processing-time timer that was set using the trigger context fires.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

onElement

public Trigger.TriggerResult onElement(Object element,
                              long timestamp,
                              TimeWindow window,
                              Trigger.TriggerContext ctx)
                                throws Exception

Description copied from interface: Trigger

Called for every element that gets added to a pane. The result of this will determine whether the pane is evaluated to emit results.

Specified by:

onElement in interface Trigger<Object,TimeWindow>

Parameters:

element - The element that arrived.

timestamp - The timestamp of the element that arrived.

window - The window to which this pane belongs.

ctx - A context object that can be used to register timer callbacks.

Throws:

Exception

onEventTime

public Trigger.TriggerResult onEventTime(long time,
                                TimeWindow window,
                                Trigger.TriggerContext ctx)

Description copied from interface: Trigger

Called when an event-time timer that was set using the trigger context fires.

Specified by:

onEventTime in interface Trigger<Object,TimeWindow>

Parameters:

time - The timestamp at which the timer fired.

ctx - A context object that can be used to register timer callbacks.

onProcessingTime

public Trigger.TriggerResult onProcessingTime(long time,
                                     TimeWindow window,
                                     Trigger.TriggerContext ctx)
                                       throws Exception

Description copied from interface: Trigger

Called when a processing-time timer that was set using the trigger context fires.

Specified by:

onProcessingTime in interface Trigger<Object,TimeWindow>

Parameters:

time - The timestamp at which the timer fired.

ctx - A context object that can be used to register timer callbacks.

Throws:

Exception

toString

public String toString()

Overrides:

toString in class Object

create

public static EventTimeTrigger create()

Creates an event-time trigger that fires once the watermark passes the end of the window.

Once the trigger fires all elements are discarded. Elements that arrive late immediately trigger window evaluation with just this one element.