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

Class TumblingWindowAssigner

java.lang.Object
org.apache.flink.table.runtime.operators.window.groupwindow.assigners.GroupWindowAssigner<TimeWindow>
org.apache.flink.table.runtime.operators.window.groupwindow.assigners.TumblingWindowAssigner
All Implemented Interfaces:
Serializable, InternalTimeWindowAssigner
public class TumblingWindowAssigner extends GroupWindowAssigner<TimeWindow> implements InternalTimeWindowAssigner
A GroupWindowAssigner that windows elements into fixed-size windows based on the timestamp of the elements. Windows cannot overlap.
See Also:

  • Constructor Details

    • TumblingWindowAssigner

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

  • Method Details

    • assignWindows

      public Collection<TimeWindow> assignWindows(org.apache.flink.table.data.RowData element, long timestamp)
      Description copied from class: GroupWindowAssigner
      Given the timestamp and element, returns the set of windows into which it should be placed.
      Specified by:
      assignWindows in class GroupWindowAssigner<TimeWindow>
      Parameters:
      element - The element to which windows should be assigned.
      timestamp - The timestamp of the element when GroupWindowAssigner.isEventTime() returns true, or the current system time when GroupWindowAssigner.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: GroupWindowAssigner
      Returns a TypeSerializer for serializing windows that are assigned by this WindowAssigner.
      Specified by:
      getWindowSerializer in class GroupWindowAssigner<TimeWindow>

    • isEventTime

      public boolean isEventTime()
      Description copied from class: GroupWindowAssigner
      Returns true if elements are assigned to windows based on event time, false otherwise.
      Specified by:
      isEventTime in class GroupWindowAssigner<TimeWindow>

    • toString

      public String toString()
      Specified by:
      toString in class GroupWindowAssigner<TimeWindow>

    • of

      public static TumblingWindowAssigner of(Duration size)
      Creates a new TumblingWindowAssigner GroupWindowAssigner 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(Duration offset)
      Creates a new TumblingWindowAssigner GroupWindowAssigner 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.