Package com.github.bannmann.labs.core

Class StreamExtras

java.lang.Object

com.github.bannmann.labs.core.StreamExtras

public final class StreamExtras
extends Object

Method Summary

Modifier and Type	Method	Description
static <T> BinaryOperator<T>	atMostOne()	Use with Stream.reduce(BinaryOperator) to ensure there is at most one element.
static <T,E extends RuntimeException> BinaryOperator<T>	atMostOneThrowing(Supplier<E> exception)	Use with Stream.reduce(BinaryOperator) to ensure there is at most one element.

Methods inherited from class java.lang.Object

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

Method Detail

atMostOne

public static <T> BinaryOperator<T> atMostOne()

Use with Stream.reduce(BinaryOperator) to ensure there is at most one element. Note that if you want an exception in case no element exists, you should instead use Guava's MoreCollectors.onlyElement().

Type Parameters:

T - element type

Returns:

an operator to use with Stream.reduce(BinaryOperator)

atMostOneThrowing

public static <T,E extends RuntimeException> BinaryOperator<T> atMostOneThrowing(Supplier<E> exception)

Use with Stream.reduce(BinaryOperator) to ensure there is at most one element. Note that if you want an exception in case no element exists, you should instead use Guava's MoreCollectors.onlyElement().

Type Parameters:

T - element type

E - type of the exception to throw if more than one element is encountered

Parameters:

exception - thrown if more than one element is encountered