Interface Aggregator


  • public interface Aggregator
    Behavior of a user-defined aggregator. Aggregates values and returns a result. In addition to the methods in the interface, implementing classes must have a 0-arg public constructor.
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void accumulate​(java.lang.Object value)
      Accumulate the next scalar value
      void init()
      Initialize the Aggregator
      java.lang.Object terminate()
      Finish the aggregation and return the operation result.
    • Method Detail

      • init

        void init()
        Initialize the Aggregator
      • accumulate

        void accumulate​(java.lang.Object value)
        Accumulate the next scalar value
        Parameters:
        value - the scalar value to accumulate
      • terminate

        java.lang.Object terminate()
        Finish the aggregation and return the operation result.
        Returns:
        Return the result scalar value