Module java.base

Package java.util.stream

Class StreamSupport

java.lang.Object

java.util.stream.StreamSupport

public final class StreamSupport
extends Object

Low-level utility methods for creating and manipulating streams.

This class is mostly for library writers presenting stream views of data structures; most static stream methods intended for end users are in the various Stream classes.

Since:

1.8

Method Summary

Modifier and Type	Method	Description
static DoubleStream	doubleStream(Supplier<? extends Spliterator.OfDouble> supplier, int characteristics, boolean parallel)	Creates a new sequential or parallel DoubleStream from a Supplier of Spliterator.OfDouble.
static DoubleStream	doubleStream(Spliterator.OfDouble spliterator, boolean parallel)	Creates a new sequential or parallel DoubleStream from a Spliterator.OfDouble.
static IntStream	intStream(Supplier<? extends Spliterator.OfInt> supplier, int characteristics, boolean parallel)	Creates a new sequential or parallel IntStream from a Supplier of Spliterator.OfInt.
static IntStream	intStream(Spliterator.OfInt spliterator, boolean parallel)	Creates a new sequential or parallel IntStream from a Spliterator.OfInt.
static LongStream	longStream(Supplier<? extends Spliterator.OfLong> supplier, int characteristics, boolean parallel)	Creates a new sequential or parallel LongStream from a Supplier of Spliterator.OfLong.
static LongStream	longStream(Spliterator.OfLong spliterator, boolean parallel)	Creates a new sequential or parallel LongStream from a Spliterator.OfLong.
static <T> Stream<T>	stream(Supplier<? extends Spliterator<T>> supplier, int characteristics, boolean parallel)	Creates a new sequential or parallel Stream from a Supplier of Spliterator.
static <T> Stream<T>	stream(Spliterator<T> spliterator, boolean parallel)	Creates a new sequential or parallel Stream from a Spliterator.

Methods declared in class java.lang.Object

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

Method Details

stream

public static <T> Stream<T> stream(Spliterator<T> spliterator,
 boolean parallel)

Creates a new sequential or parallel Stream from a Spliterator.

The spliterator is only traversed, split, or queried for estimated size after the terminal operation of the stream pipeline commences.

It is strongly recommended the spliterator report a characteristic of IMMUTABLE or CONCURRENT, or be late-binding. Otherwise, stream(java.util.function.Supplier, int, boolean) should be used to reduce the scope of potential interference with the source. See Non-Interference for more details.

Type Parameters:

T - the type of stream elements

Parameters:

spliterator - a Spliterator describing the stream elements

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel Stream

stream

public static <T> Stream<T> stream(Supplier<? extends Spliterator<T>> supplier,
 int characteristics,
 boolean parallel)

Creates a new sequential or parallel Stream from a Supplier of Spliterator.

The Supplier.get() method will be invoked on the supplier no more than once, and only after the terminal operation of the stream pipeline commences.

For spliterators that report a characteristic of IMMUTABLE or CONCURRENT, or that are late-binding, it is likely more efficient to use stream(java.util.Spliterator, boolean) instead.

The use of a Supplier in this form provides a level of indirection that reduces the scope of potential interference with the source. Since the supplier is only invoked after the terminal operation commences, any modifications to the source up to the start of the terminal operation are reflected in the stream result. See Non-Interference for more details.

Type Parameters:

T - the type of stream elements

Parameters:

supplier - a Supplier of a Spliterator

characteristics - Spliterator characteristics of the supplied Spliterator. The characteristics must be equal to supplier.get().characteristics(), otherwise undefined behavior may occur when terminal operation commences.

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel Stream

See Also:

• stream(java.util.Spliterator, boolean)

intStream

public static IntStream intStream(Spliterator.OfInt spliterator,
 boolean parallel)

Creates a new sequential or parallel IntStream from a Spliterator.OfInt.

The spliterator is only traversed, split, or queried for estimated size after the terminal operation of the stream pipeline commences.

It is strongly recommended the spliterator report a characteristic of IMMUTABLE or CONCURRENT, or be late-binding. Otherwise, intStream(java.util.function.Supplier, int, boolean) should be used to reduce the scope of potential interference with the source. See Non-Interference for more details.

Parameters:

spliterator - a Spliterator.OfInt describing the stream elements

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel IntStream

intStream

public static IntStream intStream(Supplier<? extends Spliterator.OfInt> supplier,
 int characteristics,
 boolean parallel)

Creates a new sequential or parallel IntStream from a Supplier of Spliterator.OfInt.

The Supplier.get() method will be invoked on the supplier no more than once, and only after the terminal operation of the stream pipeline commences.

For spliterators that report a characteristic of IMMUTABLE or CONCURRENT, or that are late-binding, it is likely more efficient to use intStream(java.util.Spliterator.OfInt, boolean) instead.

The use of a Supplier in this form provides a level of indirection that reduces the scope of potential interference with the source. Since the supplier is only invoked after the terminal operation commences, any modifications to the source up to the start of the terminal operation are reflected in the stream result. See Non-Interference for more details.

Parameters:

supplier - a Supplier of a Spliterator.OfInt

characteristics - Spliterator characteristics of the supplied Spliterator.OfInt. The characteristics must be equal to supplier.get().characteristics(), otherwise undefined behavior may occur when terminal operation commences.

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel IntStream

See Also:

• intStream(java.util.Spliterator.OfInt, boolean)

longStream

public static LongStream longStream(Spliterator.OfLong spliterator,
 boolean parallel)

Creates a new sequential or parallel LongStream from a Spliterator.OfLong.

The spliterator is only traversed, split, or queried for estimated size after the terminal operation of the stream pipeline commences.

It is strongly recommended the spliterator report a characteristic of IMMUTABLE or CONCURRENT, or be late-binding. Otherwise, longStream(java.util.function.Supplier, int, boolean) should be used to reduce the scope of potential interference with the source. See Non-Interference for more details.

Parameters:

spliterator - a Spliterator.OfLong describing the stream elements

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel LongStream

longStream

public static LongStream longStream(Supplier<? extends Spliterator.OfLong> supplier,
 int characteristics,
 boolean parallel)

Creates a new sequential or parallel LongStream from a Supplier of Spliterator.OfLong.

The Supplier.get() method will be invoked on the supplier no more than once, and only after the terminal operation of the stream pipeline commences.

For spliterators that report a characteristic of IMMUTABLE or CONCURRENT, or that are late-binding, it is likely more efficient to use longStream(java.util.Spliterator.OfLong, boolean) instead.

The use of a Supplier in this form provides a level of indirection that reduces the scope of potential interference with the source. Since the supplier is only invoked after the terminal operation commences, any modifications to the source up to the start of the terminal operation are reflected in the stream result. See Non-Interference for more details.

Parameters:

supplier - a Supplier of a Spliterator.OfLong

characteristics - Spliterator characteristics of the supplied Spliterator.OfLong. The characteristics must be equal to supplier.get().characteristics(), otherwise undefined behavior may occur when terminal operation commences.

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel LongStream

See Also:

• longStream(java.util.Spliterator.OfLong, boolean)

doubleStream

public static DoubleStream doubleStream(Spliterator.OfDouble spliterator,
 boolean parallel)

Creates a new sequential or parallel DoubleStream from a Spliterator.OfDouble.

The spliterator is only traversed, split, or queried for estimated size after the terminal operation of the stream pipeline commences.

It is strongly recommended the spliterator report a characteristic of IMMUTABLE or CONCURRENT, or be late-binding. Otherwise, doubleStream(java.util.function.Supplier, int, boolean) should be used to reduce the scope of potential interference with the source. See Non-Interference for more details.

Parameters:

spliterator - A Spliterator.OfDouble describing the stream elements

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel DoubleStream

doubleStream

public static DoubleStream doubleStream(Supplier<? extends Spliterator.OfDouble> supplier,
 int characteristics,
 boolean parallel)

Creates a new sequential or parallel DoubleStream from a Supplier of Spliterator.OfDouble.

The Supplier.get() method will be invoked on the supplier no more than once, and only after the terminal operation of the stream pipeline commences.

For spliterators that report a characteristic of IMMUTABLE or CONCURRENT, or that are late-binding, it is likely more efficient to use doubleStream(java.util.Spliterator.OfDouble, boolean) instead.

The use of a Supplier in this form provides a level of indirection that reduces the scope of potential interference with the source. Since the supplier is only invoked after the terminal operation commences, any modifications to the source up to the start of the terminal operation are reflected in the stream result. See Non-Interference for more details.

Parameters:

supplier - A Supplier of a Spliterator.OfDouble

characteristics - Spliterator characteristics of the supplied Spliterator.OfDouble. The characteristics must be equal to supplier.get().characteristics(), otherwise undefined behavior may occur when terminal operation commences.

parallel - if true then the returned stream is a parallel stream; if false the returned stream is a sequential stream.

Returns:

a new sequential or parallel DoubleStream

See Also:

• doubleStream(java.util.Spliterator.OfDouble, boolean)