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

Class EventTimeSessionWindows

java.lang.Object
org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<T,W>
org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>
org.apache.flink.streaming.api.windowing.assigners.EventTimeSessionWindows
All Implemented Interfaces:
Serializable
@PublicEvolving public class EventTimeSessionWindows extends org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>
A WindowAssigner that windows elements into sessions based on the timestamp of the elements. Windows cannot overlap.

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


 DataStream<Tuple2<String, Integer>> in = ...;
 KeyedStream<String, Tuple2<String, Integer>> keyed = in.keyBy(...);
 WindowedStream<Tuple2<String, Integer>, String, TimeWindows> windowed =
   keyed.window(EventTimeSessionWindows.withGap(Duration.ofMinutes(1)));
See Also:

  • Nested Class Summary

    Nested classes/interfaces inherited from class org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner

    org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner.MergeCallback<W extends Object>

    Nested classes/interfaces inherited from class org.apache.flink.streaming.api.windowing.assigners.WindowAssigner

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

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected long
    sessionTimeout
     

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    EventTimeSessionWindows(long sessionTimeout)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    Collection<org.apache.flink.streaming.api.windowing.windows.TimeWindow>
    assignWindows(Object element, long timestamp, org.apache.flink.streaming.api.windowing.assigners.WindowAssigner.WindowAssignerContext context)
     
    org.apache.flink.streaming.api.windowing.triggers.Trigger<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>
    getDefaultTrigger()
     
    org.apache.flink.api.common.typeutils.TypeSerializer<org.apache.flink.streaming.api.windowing.windows.TimeWindow>
    getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig)
     
    boolean
    isEventTime()
     
    void
    mergeWindows(Collection<org.apache.flink.streaming.api.windowing.windows.TimeWindow> windows, org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner.MergeCallback<org.apache.flink.streaming.api.windowing.windows.TimeWindow> c)
    Merge overlapping TimeWindows.
    String
    toString()
     
    static <T> DynamicEventTimeSessionWindows<T>
    withDynamicGap(SessionWindowTimeGapExtractor<T> sessionWindowTimeGapExtractor)
    Creates a new SessionWindows WindowAssigner that assigns elements to sessions based on the element timestamp.
    static EventTimeSessionWindows
    withGap(Duration size)
    Creates a new SessionWindows WindowAssigner that assigns elements to sessions based on the element timestamp.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • sessionTimeout

      protected long sessionTimeout

  • Constructor Details

    • EventTimeSessionWindows

      protected EventTimeSessionWindows(long sessionTimeout)

  • Method Details

    • assignWindows

      public Collection<org.apache.flink.streaming.api.windowing.windows.TimeWindow> assignWindows(Object element, long timestamp, org.apache.flink.streaming.api.windowing.assigners.WindowAssigner.WindowAssignerContext context)
      Specified by:
      assignWindows in class org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>

    • getDefaultTrigger

      public org.apache.flink.streaming.api.windowing.triggers.Trigger<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow> getDefaultTrigger()
      Specified by:
      getDefaultTrigger in class org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • withGap

      public static EventTimeSessionWindows withGap(Duration size)
      Creates a new SessionWindows WindowAssigner that assigns elements to sessions based on the element timestamp.
      Parameters:
      size - The session timeout, i.e. the time gap between sessions
      Returns:
      The policy.

    • withDynamicGap

      @PublicEvolving public static <T> DynamicEventTimeSessionWindows<T> withDynamicGap(SessionWindowTimeGapExtractor<T> sessionWindowTimeGapExtractor)
      Creates a new SessionWindows WindowAssigner that assigns elements to sessions based on the element timestamp.
      Parameters:
      sessionWindowTimeGapExtractor - The extractor to use to extract the time gap from the input elements
      Returns:
      The policy.

    • getWindowSerializer

      public org.apache.flink.api.common.typeutils.TypeSerializer<org.apache.flink.streaming.api.windowing.windows.TimeWindow> getWindowSerializer(org.apache.flink.api.common.ExecutionConfig executionConfig)
      Specified by:
      getWindowSerializer in class org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>

    • isEventTime

      public boolean isEventTime()
      Specified by:
      isEventTime in class org.apache.flink.streaming.api.windowing.assigners.WindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>

    • mergeWindows

      public void mergeWindows(Collection<org.apache.flink.streaming.api.windowing.windows.TimeWindow> windows, org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner.MergeCallback<org.apache.flink.streaming.api.windowing.windows.TimeWindow> c)
      Merge overlapping TimeWindows.
      Specified by:
      mergeWindows in class org.apache.flink.streaming.api.windowing.assigners.MergingWindowAssigner<Object,org.apache.flink.streaming.api.windowing.windows.TimeWindow>