org.apache.flink.streaming.api.windowing.assigners

Class SlidingTimeWindows

java.lang.Object

org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<Object,TimeWindow>

org.apache.flink.streaming.api.windowing.assigners.SlidingTimeWindows

All Implemented Interfaces:

Serializable

public class SlidingTimeWindows
extends WindowAssigner<Object,TimeWindow>

A WindowAssigner that windows elements into sliding windows based on the timestamp of the elements. Windows can possibly overlap.

For example, in order to window into windows of 1 minute, every 10 seconds:

 DataStream<Tuple2<String, Integer>> in = ...;
 KeyedStream<Tuple2<String, Integer>, String> keyed = in.keyBy(...);
 WindowedStream<Tuple2<String, Integer>, String, TimeWindow> windowed =
   keyed.window(SlidingTimeWindows.of(Time.minutes(1), Time.seconds(10)));
  

See Also:

Serialized Form

Method Summary

Methods

Modifier and Type	Method and Description
Collection<TimeWindow>	assignWindows(Object element, long timestamp) Returns a Collection of windows that should be assigned to the element.
Trigger<Object,TimeWindow>	getDefaultTrigger(StreamExecutionEnvironment env) Returns the default trigger associated with this WindowAssigner.
long	getSize()
long	getSlide()
TypeSerializer<TimeWindow>	getWindowSerializer(ExecutionConfig executionConfig) Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.
static SlidingTimeWindows	of(AbstractTime size, AbstractTime slide) Creates a new SlidingTimeWindows WindowAssigner that assigns elements to sliding time windows based on the element timestamp.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

assignWindows

public Collection<TimeWindow> assignWindows(Object element,
                                   long timestamp)

Description copied from class: WindowAssigner

Returns a Collection of windows that should be assigned to the element.

Specified by:

assignWindows in class WindowAssigner<Object,TimeWindow>

Parameters:

element - The element to which windows should be assigned.

timestamp - The timestamp of the element.

getSize

public long getSize()

getSlide

public long getSlide()

getDefaultTrigger

public Trigger<Object,TimeWindow> getDefaultTrigger(StreamExecutionEnvironment env)

Description copied from class: WindowAssigner

Returns the default trigger associated with this WindowAssigner.

Specified by:

getDefaultTrigger in class WindowAssigner<Object,TimeWindow>

toString

public String toString()

Overrides:

toString in class Object

of

public static SlidingTimeWindows of(AbstractTime size,
                    AbstractTime slide)

Creates a new SlidingTimeWindows WindowAssigner that assigns elements to sliding time windows based on the element timestamp.

Parameters:

size - The size of the generated windows.

slide - The slide interval of the generated windows.

Returns:

The time policy.

getWindowSerializer

public TypeSerializer<TimeWindow> getWindowSerializer(ExecutionConfig executionConfig)

Description copied from class: WindowAssigner

Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.

Specified by:

getWindowSerializer in class WindowAssigner<Object,TimeWindow>