Package one.x1f.sip.foundation.core.util

Class StreamHelper

java.lang.Object

one.x1f.sip.foundation.core.util.StreamHelper

public class StreamHelper
extends Object

Constructor Summary

Constructors

Constructor	Description
StreamHelper()

Method Summary

Modifier and Type	Method	Description
static <T> Optional<T>	findAtMostOne(Stream<T> stream, Predicate<T> predicate, Supplier<RuntimeException> multipleException)	Returns at most one element from the given stream matching the given predicate, but throws the exception retrieved from multipleException if more match.
static <S, T extends S> Function<S,Stream<T>>	typeFilter(Class<T> type)	Filters a stream of objects by type.

Methods inherited from class java.lang.Object

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

Constructor Details

StreamHelper

public StreamHelper()

Method Details

typeFilter

public static <S,
T extends S> Function<S,Stream<T>> typeFilter(Class<T> type)

Filters a stream of objects by type.

Usage example: List<Object>.stream().flatMap(typeFilter(String.class)).toList()

Type Parameters:

S - The type of the stream

T - Filtering type

Parameters:

type - The filtering type

Returns:

Filtering function

findAtMostOne

public static <T> Optional<T> findAtMostOne(Stream<T> stream,
 Predicate<T> predicate,
 Supplier<RuntimeException> multipleException)

Returns at most one element from the given stream matching the given predicate, but throws the exception retrieved from multipleException if more match.

Type Parameters:

T - Element type

Parameters:

stream - Stream to retrieve unique element from

predicate - Predicate for filtering

multipleException - Error thrown if more than one element matches the predicate

Returns:

Optional element found