Package org.keycloak.utils

Class StreamsUtil

java.lang.Object

org.keycloak.utils.StreamsUtil

public class StreamsUtil
extends Object

Constructor Summary

Constructors

Constructor	Description
StreamsUtil()

Method Summary

Modifier and Type	Method	Description
static <T> Stream<T>	closing(Stream<T> stream)	Returns the original stream that is closed on terminating operation.
static <T> Predicate<T>	distinctByKey(Function<? super T,?> keyExtractor)	distinctByKey is not supposed to be used with parallel streams To make this method synchronized use ConcurrentHashMap<Object, Boolean> instead of HashSet
static <T> Stream<T>	paginatedStream(Stream<T> originalStream, Integer first, Integer max)	Returns the original stream that is limited with skip and limit functions based on values of first and max parameters.
static <T> Stream<T>	throwIfEmpty(Stream<T> stream, RuntimeException ex)	Returns the original stream if the stream is not empty.

Methods inherited from class java.lang.Object

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

Constructor Details

StreamsUtil

public StreamsUtil()

Method Details

closing

public static <T> Stream<T> closing(Stream<T> stream)

Returns the original stream that is closed on terminating operation. It is used, for example, for closing hibernate provided streams since it is required by hibernate documentation.

Parameters:

stream - the stream which is expected to be closed on termination

Returns:

stream that will be closed on terminating operation

throwIfEmpty

public static <T> Stream<T> throwIfEmpty(Stream<T> stream,
 RuntimeException ex)

Returns the original stream if the stream is not empty. Otherwise throws the provided exception.

Parameters:

stream - Stream to be examined.

ex - Exception to be thrown if the stream is empty.

Returns:

Stream

paginatedStream

public static <T> Stream<T> paginatedStream(Stream<T> originalStream,
 Integer first,
 Integer max)

Returns the original stream that is limited with skip and limit functions based on values of first and max parameters.

Type Parameters:

T - Type of items in the stream

Parameters:

originalStream - Stream to be limited.

first - Index of first item to be returned by the stream. Ignored if negative, zero null.

max - Maximum number of items to be returned by the stream. Ignored if negative or null.

Returns:

Stream

distinctByKey

public static <T> Predicate<T> distinctByKey(Function<? super T,?> keyExtractor)

distinctByKey is not supposed to be used with parallel streams To make this method synchronized use ConcurrentHashMap<Object, Boolean> instead of HashSet