Module java.base
Package java.util

Class Spliterators

java.lang.Object
java.util.Spliterators
public final class Spliterators extends Object
Static classes and methods for operating on or creating instances of Spliterator and its primitive specializations Spliterator.OfInt, Spliterator.OfLong, and Spliterator.OfDouble.
Since:
1.8
See Also:
Spliterator

  • Method Details

    • emptySpliterator

      public static <T> Spliterator<T> emptySpliterator()
      Creates an empty Spliterator

      The empty spliterator reports Spliterator.SIZED and Spliterator.SUBSIZED. Calls to Spliterator.trySplit() always return null.

      Type Parameters:
      T - Type of elements
      Returns:
      An empty spliterator

    • emptyIntSpliterator

      public static Spliterator.OfInt emptyIntSpliterator()
      Creates an empty Spliterator.OfInt

      The empty spliterator reports Spliterator.SIZED and Spliterator.SUBSIZED. Calls to Spliterator.trySplit() always return null.

      Returns:
      An empty spliterator

    • emptyLongSpliterator

      public static Spliterator.OfLong emptyLongSpliterator()
      Creates an empty Spliterator.OfLong

      The empty spliterator reports Spliterator.SIZED and Spliterator.SUBSIZED. Calls to Spliterator.trySplit() always return null.

      Returns:
      An empty spliterator

    • emptyDoubleSpliterator

      public static Spliterator.OfDouble emptyDoubleSpliterator()
      Creates an empty Spliterator.OfDouble

      The empty spliterator reports Spliterator.SIZED and Spliterator.SUBSIZED. Calls to Spliterator.trySplit() always return null.

      Returns:
      An empty spliterator

    • spliterator

      public static <T> Spliterator<T> spliterator​(Object[] array, int additionalCharacteristics)
      Creates a Spliterator covering the elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(Object[]).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Type Parameters:
      T - Type of elements
      Parameters:
      array - The array, assumed to be unmodified during use
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      See Also:
      Arrays.spliterator(Object[])

    • spliterator

      public static <T> Spliterator<T> spliterator​(Object[] array, int fromIndex, int toIndex, int additionalCharacteristics)
      Creates a Spliterator covering a range of elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(Object[]).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Type Parameters:
      T - Type of elements
      Parameters:
      array - The array, assumed to be unmodified during use
      fromIndex - The least index (inclusive) to cover
      toIndex - One past the greatest index to cover
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      ArrayIndexOutOfBoundsException - if fromIndex is negative, toIndex is less than fromIndex, or toIndex is greater than the array size
      See Also:
      Arrays.spliterator(Object[], int, int)

    • spliterator

      public static Spliterator.OfInt spliterator​(int[] array, int additionalCharacteristics)
      Creates a Spliterator.OfInt covering the elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(int[]).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      See Also:
      Arrays.spliterator(int[])

    • spliterator

      public static Spliterator.OfInt spliterator​(int[] array, int fromIndex, int toIndex, int additionalCharacteristics)
      Creates a Spliterator.OfInt covering a range of elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(int[], int, int).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      fromIndex - The least index (inclusive) to cover
      toIndex - One past the greatest index to cover
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      ArrayIndexOutOfBoundsException - if fromIndex is negative, toIndex is less than fromIndex, or toIndex is greater than the array size
      See Also:
      Arrays.spliterator(int[], int, int)

    • spliterator

      public static Spliterator.OfLong spliterator​(long[] array, int additionalCharacteristics)
      Creates a Spliterator.OfLong covering the elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(long[]).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      See Also:
      Arrays.spliterator(long[])

    • spliterator

      public static Spliterator.OfLong spliterator​(long[] array, int fromIndex, int toIndex, int additionalCharacteristics)
      Creates a Spliterator.OfLong covering a range of elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(long[], int, int).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report. (For example, if it is known the array will not be further modified, specify IMMUTABLE; if the array data is considered to have an encounter order, specify ORDERED). The method Arrays.spliterator(long[], int, int) can often be used instead, which returns a spliterator that reports SIZED, SUBSIZED, IMMUTABLE, and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      fromIndex - The least index (inclusive) to cover
      toIndex - One past the greatest index to cover
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      ArrayIndexOutOfBoundsException - if fromIndex is negative, toIndex is less than fromIndex, or toIndex is greater than the array size
      See Also:
      Arrays.spliterator(long[], int, int)

    • spliterator

      public static Spliterator.OfDouble spliterator​(double[] array, int additionalCharacteristics)
      Creates a Spliterator.OfDouble covering the elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(double[]).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report; it is common to additionally specify IMMUTABLE and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      See Also:
      Arrays.spliterator(double[])

    • spliterator

      public static Spliterator.OfDouble spliterator​(double[] array, int fromIndex, int toIndex, int additionalCharacteristics)
      Creates a Spliterator.OfDouble covering a range of elements of a given array, using a customized set of spliterator characteristics.

      This method is provided as an implementation convenience for Spliterators which store portions of their elements in arrays, and need fine control over Spliterator characteristics. Most other situations in which a Spliterator for an array is needed should use Arrays.spliterator(double[], int, int).

      The returned spliterator always reports the characteristics SIZED and SUBSIZED. The caller may provide additional characteristics for the spliterator to report. (For example, if it is known the array will not be further modified, specify IMMUTABLE; if the array data is considered to have an encounter order, specify ORDERED). The method Arrays.spliterator(long[], int, int) can often be used instead, which returns a spliterator that reports SIZED, SUBSIZED, IMMUTABLE, and ORDERED.

      Parameters:
      array - The array, assumed to be unmodified during use
      fromIndex - The least index (inclusive) to cover
      toIndex - One past the greatest index to cover
      additionalCharacteristics - Additional spliterator characteristics of this spliterator's source or elements beyond SIZED and SUBSIZED which are always reported
      Returns:
      A spliterator for an array
      Throws:
      NullPointerException - if the given array is null
      ArrayIndexOutOfBoundsException - if fromIndex is negative, toIndex is less than fromIndex, or toIndex is greater than the array size
      See Also:
      Arrays.spliterator(double[], int, int)

    • spliterator

      public static <T> Spliterator<T> spliterator​(Collection<? extends T> c, int characteristics)
      Creates a Spliterator using the given collection's Collection.iterator() as the source of elements, and reporting its Collection.size() as its initial size.

      The spliterator is late-binding, inherits the fail-fast properties of the collection's iterator, and implements trySplit to permit limited parallelism.

      Type Parameters:
      T - Type of elements
      Parameters:
      c - The collection
      characteristics - Characteristics of this spliterator's source or elements. The characteristics SIZED and SUBSIZED are additionally reported unless CONCURRENT is supplied.
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given collection is null

    • spliterator

      public static <T> Spliterator<T> spliterator​(Iterator<? extends T> iterator, long size, int characteristics)
      Creates a Spliterator using a given Iterator as the source of elements, and with a given initially reported size.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned, or the initially reported size is not equal to the actual number of elements in the source.

      Type Parameters:
      T - Type of elements
      Parameters:
      iterator - The iterator for the source
      size - The number of elements in the source, to be reported as initial estimateSize
      characteristics - Characteristics of this spliterator's source or elements. The characteristics SIZED and SUBSIZED are additionally reported unless CONCURRENT is supplied.
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliteratorUnknownSize

      public static <T> Spliterator<T> spliteratorUnknownSize​(Iterator<? extends T> iterator, int characteristics)
      Creates a Spliterator using a given Iterator as the source of elements, with no initial size estimate.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned.

      Type Parameters:
      T - Type of elements
      Parameters:
      iterator - The iterator for the source
      characteristics - Characteristics of this spliterator's source or elements (SIZED and SUBSIZED, if supplied, are ignored and are not reported.)
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliterator

      public static Spliterator.OfInt spliterator​(PrimitiveIterator.OfInt iterator, long size, int characteristics)
      Creates a Spliterator.OfInt using a given IntStream.IntIterator as the source of elements, and with a given initially reported size.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned, or the initially reported size is not equal to the actual number of elements in the source.

      Parameters:
      iterator - The iterator for the source
      size - The number of elements in the source, to be reported as initial estimateSize.
      characteristics - Characteristics of this spliterator's source or elements. The characteristics SIZED and SUBSIZED are additionally reported unless CONCURRENT is supplied.
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliteratorUnknownSize

      public static Spliterator.OfInt spliteratorUnknownSize​(PrimitiveIterator.OfInt iterator, int characteristics)
      Creates a Spliterator.OfInt using a given IntStream.IntIterator as the source of elements, with no initial size estimate.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned.

      Parameters:
      iterator - The iterator for the source
      characteristics - Characteristics of this spliterator's source or elements (SIZED and SUBSIZED, if supplied, are ignored and are not reported.)
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliterator

      public static Spliterator.OfLong spliterator​(PrimitiveIterator.OfLong iterator, long size, int characteristics)
      Creates a Spliterator.OfLong using a given LongStream.LongIterator as the source of elements, and with a given initially reported size.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned, or the initially reported size is not equal to the actual number of elements in the source.

      Parameters:
      iterator - The iterator for the source
      size - The number of elements in the source, to be reported as initial estimateSize.
      characteristics - Characteristics of this spliterator's source or elements. The characteristics SIZED and SUBSIZED are additionally reported unless CONCURRENT is supplied.
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliteratorUnknownSize

      public static Spliterator.OfLong spliteratorUnknownSize​(PrimitiveIterator.OfLong iterator, int characteristics)
      Creates a Spliterator.OfLong using a given LongStream.LongIterator as the source of elements, with no initial size estimate.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned.

      Parameters:
      iterator - The iterator for the source
      characteristics - Characteristics of this spliterator's source or elements (SIZED and SUBSIZED, if supplied, are ignored and are not reported.)
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliterator

      public static Spliterator.OfDouble spliterator​(PrimitiveIterator.OfDouble iterator, long size, int characteristics)
      Creates a Spliterator.OfDouble using a given DoubleStream.DoubleIterator as the source of elements, and with a given initially reported size.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned, or the initially reported size is not equal to the actual number of elements in the source.

      Parameters:
      iterator - The iterator for the source
      size - The number of elements in the source, to be reported as initial estimateSize
      characteristics - Characteristics of this spliterator's source or elements. The characteristics SIZED and SUBSIZED are additionally reported unless CONCURRENT is supplied.
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • spliteratorUnknownSize

      public static Spliterator.OfDouble spliteratorUnknownSize​(PrimitiveIterator.OfDouble iterator, int characteristics)
      Creates a Spliterator.OfDouble using a given DoubleStream.DoubleIterator as the source of elements, with no initial size estimate.

      The spliterator is not late-binding, inherits the fail-fast properties of the iterator, and implements trySplit to permit limited parallelism.

      Traversal of elements should be accomplished through the spliterator. The behaviour of splitting and traversal is undefined if the iterator is operated on after the spliterator is returned.

      Parameters:
      iterator - The iterator for the source
      characteristics - Characteristics of this spliterator's source or elements (SIZED and SUBSIZED, if supplied, are ignored and are not reported.)
      Returns:
      A spliterator from an iterator
      Throws:
      NullPointerException - if the given iterator is null

    • iterator

      public static <T> Iterator<T> iterator​(Spliterator<? extends T> spliterator)
      Creates an Iterator from a Spliterator.

      Traversal of elements should be accomplished through the iterator. The behaviour of traversal is undefined if the spliterator is operated after the iterator is returned.

      Type Parameters:
      T - Type of elements
      Parameters:
      spliterator - The spliterator
      Returns:
      An iterator
      Throws:
      NullPointerException - if the given spliterator is null

    • iterator

      public static PrimitiveIterator.OfInt iterator​(Spliterator.OfInt spliterator)
      Creates an PrimitiveIterator.OfInt from a Spliterator.OfInt.

      Traversal of elements should be accomplished through the iterator. The behaviour of traversal is undefined if the spliterator is operated after the iterator is returned.

      Parameters:
      spliterator - The spliterator
      Returns:
      An iterator
      Throws:
      NullPointerException - if the given spliterator is null

    • iterator

      public static PrimitiveIterator.OfLong iterator​(Spliterator.OfLong spliterator)
      Creates an PrimitiveIterator.OfLong from a Spliterator.OfLong.

      Traversal of elements should be accomplished through the iterator. The behaviour of traversal is undefined if the spliterator is operated after the iterator is returned.

      Parameters:
      spliterator - The spliterator
      Returns:
      An iterator
      Throws:
      NullPointerException - if the given spliterator is null

    • iterator

      public static PrimitiveIterator.OfDouble iterator​(Spliterator.OfDouble spliterator)
      Creates an PrimitiveIterator.OfDouble from a Spliterator.OfDouble.

      Traversal of elements should be accomplished through the iterator. The behaviour of traversal is undefined if the spliterator is operated after the iterator is returned.

      Parameters:
      spliterator - The spliterator
      Returns:
      An iterator
      Throws:
      NullPointerException - if the given spliterator is null