Package org.apache.flink.table.runtime.operators.window.assigners

Class TumblingWindowAssigner

java.lang.Object

org.apache.flink.table.runtime.operators.window.assigners.WindowAssigner<TimeWindow>

org.apache.flink.table.runtime.operators.window.assigners.TumblingWindowAssigner

All Implemented Interfaces:

Serializable, InternalTimeWindowAssigner

public class TumblingWindowAssigner
extends WindowAssigner<TimeWindow>
implements InternalTimeWindowAssigner

A WindowAssigner that windows elements into fixed-size windows based on the timestamp of the elements. Windows cannot overlap.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TumblingWindowAssigner(long size, long offset, boolean isEventTime)

Method Summary

Modifier and Type	Method	Description
Collection<TimeWindow>	assignWindows(org.apache.flink.table.data.RowData element, long timestamp)	Given the timestamp and element, returns the set of windows into which it should be placed.
org.apache.flink.api.common.typeutils.TypeSerializer<TimeWindow>	getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig)	Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.
boolean	isEventTime()	Returns true if elements are assigned to windows based on event time, false otherwise.
static TumblingWindowAssigner	of(java.time.Duration size)	Creates a new TumblingWindowAssigner WindowAssigner that assigns elements to time windows based on the element timestamp.
String	toString()
TumblingWindowAssigner	withEventTime()
TumblingWindowAssigner	withOffset(java.time.Duration offset)	Creates a new TumblingWindowAssigner WindowAssigner that assigns elements to time windows based on the element timestamp and offset.
TumblingWindowAssigner	withProcessingTime()

Methods inherited from class org.apache.flink.table.runtime.operators.window.assigners.WindowAssigner

open

Methods inherited from class java.lang.Object

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

Constructor Detail

TumblingWindowAssigner

protected TumblingWindowAssigner(long size,
                                 long offset,
                                 boolean isEventTime)

Method Detail

assignWindows

public Collection<TimeWindow> assignWindows(org.apache.flink.table.data.RowData element,
                                            long timestamp)

Description copied from class: WindowAssigner

Given the timestamp and element, returns the set of windows into which it should be placed.

Specified by:

assignWindows in class WindowAssigner<TimeWindow>

Parameters:

element - The element to which windows should be assigned.

timestamp - The timestamp of the element when WindowAssigner.isEventTime() returns true, or the current system time when WindowAssigner.isEventTime() returns false. The timestamp value is mapping to UTC milliseconds for splitting windows simply.

getWindowSerializer

public org.apache.flink.api.common.typeutils.TypeSerializer<TimeWindow> getWindowSerializer(org.apache.flink.api.common.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<TimeWindow>

isEventTime

public boolean isEventTime()

Description copied from class: WindowAssigner

Returns true if elements are assigned to windows based on event time, false otherwise.

Specified by:

isEventTime in class WindowAssigner<TimeWindow>

toString

public String toString()

Specified by:

toString in class WindowAssigner<TimeWindow>

of

public static TumblingWindowAssigner of(java.time.Duration size)

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

Parameters:

size - The size of the generated windows.

Returns:

The time policy.

withOffset

public TumblingWindowAssigner withOffset(java.time.Duration offset)

Creates a new TumblingWindowAssigner WindowAssigner that assigns elements to time windows based on the element timestamp and offset.

For example, if you want window a stream by hour,but window begins at the 15th minutes of each hour, you can use of(Time.hours(1),Time.minutes(15)),then you will get time windows start at 0:15:00,1:15:00,2:15:00,etc.

Rather than that,if you are living in somewhere which is not using UTC±00:00 time, such as China which is using GMT+08:00,and you want a time window with size of one day, and window begins at every 00:00:00 of local time,you may use of(Time.days(1),Time.hours(-8)). The parameter of offset is Time.hours(-8)) since UTC+08:00 is 8 hours earlier than UTC time.

Parameters:

offset - The offset which window start would be shifted by.

Returns:

The time policy.

withEventTime

public TumblingWindowAssigner withEventTime()

Specified by:

withEventTime in interface InternalTimeWindowAssigner

Returns:

an InternalTimeWindowAssigner which in event time mode.

withProcessingTime

public TumblingWindowAssigner withProcessingTime()

Specified by:

withProcessingTime in interface InternalTimeWindowAssigner

Returns:

an InternalTimeWindowAssigner which in processing time mode.