StreamUtils (Spring Data Core 2.1.3.RELEASE API)

```
public interface StreamUtils
```
Spring Data specific Java Stream utility methods and classes.

Since:

1.10

Author:

Thomas Darimont, Oliver Gierke

Method Summary

All Methods Static Methods Default Methods
Modifier and Type	Method and Description
`static <T> Stream<T>`	`createStreamFromIterator(CloseableIterator<T> iterator)` Returns a `Stream` backed by the given `CloseableIterator` and forwarding calls to `BaseStream.close()` to the iterator.
`static <T> Stream<T>`	`createStreamFromIterator(Iterator<T> iterator)` Returns a `Stream` backed by the given `Iterator`
`static <T> Stream<T>`	`fromNullable(T source)` Creates a new `Stream` for the given value returning an empty `Stream` if the value is null.
`static <T,K,V> Collector<T,MultiValueMap<K,V>,MultiValueMap<K,V>>`	`toMultiMap(Function<T,K> keyFunction, Function<T,V> valueFunction)` Returns a `Collector` to create a `MultiValueMap`.
`static <T> Collector<T,?,List<T>>`	`toUnmodifiableList()` Returns a `Collector` to create an unmodifiable `List`.
`static <T> Collector<T,?,Set<T>>`	`toUnmodifiableSet()` Returns a `Collector` to create an unmodifiable `Set`.
`static <L,R,T> Stream<T>`	`zip(Stream<L> left, Stream<R> right, BiFunction<L,R,T> combiner)` Zips the given `Stream`s using the given `BiFunction`.

- Method Detail
  - createStreamFromIterator
```
static <T> Stream<T> createStreamFromIterator(Iterator<T> iterator)
```
    Returns a Stream backed by the given Iterator
    
    Parameters:
    
    iterator - must not be null.
    
    Returns:
  - createStreamFromIterator
```
static <T> Stream<T> createStreamFromIterator(CloseableIterator<T> iterator)
```
    Returns a Stream backed by the given CloseableIterator and forwarding calls to BaseStream.close() to the iterator.
    
    Parameters:
    
    iterator - must not be null.
    
    Returns:
    
    Since:
    
    2.0
  - toUnmodifiableList
```
static <T> Collector<T,?,List<T>> toUnmodifiableList()
```
    Returns a Collector to create an unmodifiable List.
    
    Returns:
    
    will never be null.
  - toUnmodifiableSet
```
static <T> Collector<T,?,Set<T>> toUnmodifiableSet()
```
    Returns a Collector to create an unmodifiable Set.
    
    Returns:
    
    will never be null.
  - toMultiMap
```
static <T,K,V> Collector<T,MultiValueMap<K,V>,MultiValueMap<K,V>> toMultiMap(Function<T,K> keyFunction,
                                                                             Function<T,V> valueFunction)
```
    Returns a Collector to create a MultiValueMap.
    
    Parameters:
    
    keyFunction - Function to create a key from an element of the Stream
    
    valueFunction - Function to create a value from an element of the Stream
  - fromNullable
```
static <T> Stream<T> fromNullable(@Nullable
                                  T source)
```
    Creates a new Stream for the given value returning an empty Stream if the value is null.
    
    Parameters:
    
    source - can be null.
    
    Returns:
    
    a new Stream for the given value returning an empty Stream if the value is null.
    
    Since:
    
    2.0.6
  - zip
```
static <L,R,T> Stream<T> zip(Stream<L> left,
                             Stream<R> right,
                             BiFunction<L,R,T> combiner)
```
    Zips the given Streams using the given BiFunction. The resulting Stream will have the length of the shorter of the two, abbreviating the zipping when the shorter of the two Streams is exhausted.
    
    Parameters:
    
    left - must not be null.
    
    right - must not be null.
    
    combiner - must not be null.
    
    Returns:
    
    Since:
    
    2.1

Interface StreamUtils

Method Summary

Method Detail

createStreamFromIterator

createStreamFromIterator

toUnmodifiableList

toUnmodifiableSet

toMultiMap

fromNullable

zip