Package org.springframework.data.domain

Interface Window<T>

All Superinterfaces:

Iterable<T>, Streamable<T>, Supplier<Stream<T>>

public interface Window<T>
extends Streamable<T>

A set of data consumed from an underlying query result. A Window is similar to Slice in the sense that it contains a subset of the actual query results for easier scrolling across large result sets. The window is less opinionated about the actual data retrieval, whether the query has used index/offset, keyset-based pagination or cursor resume tokens.

Since:

3.1

Author:

Mark Paluch, Christoph Strobl

See Also:

• ScrollPosition

Method Summary

Modifier and Type	Method	Description
static <T> Window<T>	from(List<T> items, IntFunction<? extends ScrollPosition> positionFunction)	Construct a Window.
static <T> Window<T>	from(List<T> items, IntFunction<? extends ScrollPosition> positionFunction, boolean hasNext)	Construct a Window.
List<T>	getContent()	Returns the windows content as List.
boolean	hasNext()	Returns if there is a next window.
default boolean	hasPosition(int index)	Returns whether the underlying scroll mechanism can provide a ScrollPosition at index.
boolean	isEmpty()	Returns true if this window contains no elements.
default boolean	isLast()	Returns whether the current window is the last one.
<U> Window<U>	map(Function<? super T,? extends U> converter)	Returns a new Window with the content of the current one mapped by the given converter.
ScrollPosition	positionAt(int index)	Returns the ScrollPosition at index.
default ScrollPosition	positionAt(T object)	Returns the ScrollPosition for object.
int	size()	Returns the number of elements in this window.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Methods inherited from interface org.springframework.data.util.Streamable

and, and, and, and, filter, flatMap, get, stream, toList, toSet

Method Details

from

static <T> Window<T> from(List<T> items,
 IntFunction<? extends ScrollPosition> positionFunction)

Construct a Window.

Type Parameters:

T -

Parameters:

items - the list of data.

positionFunction - the list of data.

Returns:

the Window.

from

static <T> Window<T> from(List<T> items,
 IntFunction<? extends ScrollPosition> positionFunction,
 boolean hasNext)

Construct a Window.

Type Parameters:

T -

Parameters:

items - the list of data.

positionFunction - the list of data.

hasNext -

Returns:

the Window.

size

int size()

Returns the number of elements in this window.

Returns:

the number of elements in this window.

isEmpty

boolean isEmpty()

Returns true if this window contains no elements.

Specified by:

isEmpty in interface Streamable<T>

Returns:

true if this window contains no elements

getContent

List<T> getContent()

Returns the windows content as List.

Returns:

isLast

default boolean isLast()

Returns whether the current window is the last one.

Returns:

hasNext

boolean hasNext()

Returns if there is a next window.

Returns:

if there is a next window.

hasPosition

default boolean hasPosition(int index)

Returns whether the underlying scroll mechanism can provide a ScrollPosition at index.

Parameters:

index -

Returns:

true if a ScrollPosition can be created; false otherwise.

See Also:

• positionAt(int)

positionAt

ScrollPosition positionAt(int index)

Returns the ScrollPosition at index.

Parameters:

index -

Returns:

Throws:

IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= size()).

IllegalStateException - if the underlying scroll mechanism cannot provide a scroll position for the given object.

positionAt

default ScrollPosition positionAt(T object)

Returns the ScrollPosition for object.

Parameters:

object -

Returns:

Throws:

NoSuchElementException - if the object is not part of the result.

IllegalStateException - if the underlying scroll mechanism cannot provide a scroll position for the given object.

map

<U> Window<U> map(Function<? super T,? extends U> converter)

Returns a new Window with the content of the current one mapped by the given converter.

Specified by:

map in interface Streamable<T>

Parameters:

converter - must not be null.

Returns:

a new Window with the content of the current one mapped by the given converter.

See Also:

• Stream.map(Function)