Package org.apache.kafka.streams.kstream

Interface EmitStrategy

public interface EmitStrategy
This interface controls the strategy that can be used to control how we emit results in a processor.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Interface
    Description
    static enum 
    EmitStrategy.StrategyType
     

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final org.slf4j.Logger
    log
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static EmitStrategy
    onWindowClose()
    This strategy indicates that the aggregated result for a window will only be emitted when the window closes instead of when there's an update to the window.
    static EmitStrategy
    onWindowUpdate()
    This strategy indicates that the aggregated result for a window will be emitted every time when there's an update to the window instead of when the window closes.
    EmitStrategy.StrategyType
    type()
    Returns the strategy type.

  • Field Details

    • log

      static final org.slf4j.Logger log

  • Method Details

    • type

      EmitStrategy.StrategyType type()
      Returns the strategy type.
      Returns:
      Emit strategy type

    • onWindowClose

      static EmitStrategy onWindowClose()
      This strategy indicates that the aggregated result for a window will only be emitted when the window closes instead of when there's an update to the window. Window close means that current event time is larger than (window end time + grace period).

      This strategy should only be used for windows which can close. An exception will be thrown if it's used with UnlimitedWindow.

      Returns:
      "window close" EmitStrategy instance
      See Also:

    • onWindowUpdate

      static EmitStrategy onWindowUpdate()
      This strategy indicates that the aggregated result for a window will be emitted every time when there's an update to the window instead of when the window closes.
      Returns:
      "window update" EmitStrategy instance
      See Also: