org.apache.flink.api.common.functions

Interface CrossFunction<IN1,IN2,OUT>

Type Parameters:

IN1 - The type of the elements in the first input.

IN2 - The type of the elements in the second input.

OUT - The type of the result elements.

All Superinterfaces:

Function, Serializable

All Known Implementing Classes:

CrossOperator.ProjectCrossFunction, RichCrossFunction

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@Public
 @FunctionalInterface
public interface CrossFunction<IN1,IN2,OUT>
extends Function, Serializable

Interface for Cross functions. Cross functions are applied to the Cartesian product of their inputs and are called for each pair of elements.

They are optional, a means of convenience that can be used to directly manipulate the pair of elements instead of producing 2-tuples containing the pairs.

The basic syntax for using Cross on two data sets is as follows:

 DataSet<X> set1 = ...;
 DataSet<Y> set2 = ...;

 set1.cross(set2).with(new MyCrossFunction());
 

set1 is here considered the first input, set2 the second input.

Method Summary

Modifier and Type	Method and Description
OUT	cross(IN1 val1, IN2 val2) Cross UDF method.

Method Detail

cross

OUT cross(IN1 val1,
          IN2 val2)
   throws Exception

Cross UDF method. Called once per pair of elements in the Cartesian product of the inputs.

Parameters:

val1 - Element from first input.

val2 - Element from the second input.

Returns:

The result element.

Throws:

Exception - The function may throw Exceptions, which will cause the program to cancel, and may trigger the recovery logic.