public interface IntStream extends BaseStream<Integer,IntStream>
int primitive specialization of
 Stream.
 The following example illustrates an aggregate operation using
 Stream and IntStream, computing the sum of the weights of the
 red widgets:
 
     int sum = widgets.stream()
                      .filter(w -> w.getColor() == RED)
                      .mapToInt(w -> w.getWeight())
                      .sum();
 Stream and the package documentation
 for java.util.stream for additional
 specification of streams, stream operations, stream pipelines, and
 parallelism.Stream, 
java.util.stream| Modifier and Type | Interface and Description | 
|---|---|
| static interface  | IntStream.BuilderA mutable builder for an  IntStream. | 
| Modifier and Type | Method and Description | 
|---|---|
| boolean | allMatch(IntPredicate predicate)Returns whether all elements of this stream match the provided predicate. | 
| boolean | anyMatch(IntPredicate predicate)Returns whether any elements of this stream match the provided
 predicate. | 
| DoubleStream | asDoubleStream()Returns a  DoubleStreamconsisting of the elements of this stream,
 converted todouble. | 
| LongStream | asLongStream()Returns a  LongStreamconsisting of the elements of this stream,
 converted tolong. | 
| OptionalDouble | average()Returns an  OptionalDoubledescribing the arithmetic mean of elements of
 this stream, or an empty optional if this stream is empty. | 
| Stream<Integer> | boxed()Returns a  Streamconsisting of the elements of this stream,
 each boxed to anInteger. | 
| static IntStream.Builder | builder()Returns a builder for an  IntStream. | 
| <R> R | collect(Supplier<R> supplier,
       ObjIntConsumer<R> accumulator,
       BiConsumer<R,R> combiner)Performs a mutable
 reduction operation on the elements of this stream. | 
| static IntStream | concat(IntStream a,
      IntStream b)Creates a lazily concatenated stream whose elements are all the
 elements of the first stream followed by all the elements of the
 second stream. | 
| long | count()Returns the count of elements in this stream. | 
| IntStream | distinct()Returns a stream consisting of the distinct elements of this stream. | 
| static IntStream | empty()Returns an empty sequential  IntStream. | 
| IntStream | filter(IntPredicate predicate)Returns a stream consisting of the elements of this stream that match
 the given predicate. | 
| OptionalInt | findAny()Returns an  OptionalIntdescribing some element of the stream, or
 an emptyOptionalIntif the stream is empty. | 
| OptionalInt | findFirst()Returns an  OptionalIntdescribing the first element of this
 stream, or an emptyOptionalIntif the stream is empty. | 
| IntStream | flatMap(IntFunction<? extends IntStream> mapper)Returns a stream consisting of the results of replacing each element of
 this stream with the contents of a mapped stream produced by applying
 the provided mapping function to each element. | 
| void | forEach(IntConsumer action)Performs an action for each element of this stream. | 
| void | forEachOrdered(IntConsumer action)Performs an action for each element of this stream, guaranteeing that
 each element is processed in encounter order for streams that have a
 defined encounter order. | 
| static IntStream | generate(IntSupplier s)Returns an infinite sequential unordered stream where each element is
 generated by the provided  IntSupplier. | 
| static IntStream | iterate(int seed,
       IntUnaryOperator f)Returns an infinite sequential ordered  IntStreamproduced by iterative
 application of a functionfto an initial elementseed,
 producing aStreamconsisting ofseed,f(seed),f(f(seed)), etc. | 
| PrimitiveIterator.OfInt | iterator()Returns an iterator for the elements of this stream. | 
| IntStream | limit(long maxSize)Returns a stream consisting of the elements of this stream, truncated
 to be no longer than  maxSizein length. | 
| IntStream | map(IntUnaryOperator mapper)Returns a stream consisting of the results of applying the given
 function to the elements of this stream. | 
| DoubleStream | mapToDouble(IntToDoubleFunction mapper)Returns a  DoubleStreamconsisting of the results of applying the
 given function to the elements of this stream. | 
| LongStream | mapToLong(IntToLongFunction mapper)Returns a  LongStreamconsisting of the results of applying the
 given function to the elements of this stream. | 
| <U> Stream<U> | mapToObj(IntFunction<? extends U> mapper)Returns an object-valued  Streamconsisting of the results of
 applying the given function to the elements of this stream. | 
| OptionalInt | max()Returns an  OptionalIntdescribing the maximum element of this
 stream, or an empty optional if this stream is empty. | 
| OptionalInt | min()Returns an  OptionalIntdescribing the minimum element of this
 stream, or an empty optional if this stream is empty. | 
| boolean | noneMatch(IntPredicate predicate)Returns whether no elements of this stream match the provided predicate. | 
| static IntStream | of(int... values)Returns a sequential ordered stream whose elements are the specified values. | 
| static IntStream | of(int t)Returns a sequential  IntStreamcontaining a single element. | 
| IntStream | parallel()Returns an equivalent stream that is parallel. | 
| IntStream | peek(IntConsumer action)Returns a stream consisting of the elements of this stream, additionally
 performing the provided action on each element as elements are consumed
 from the resulting stream. | 
| static IntStream | range(int startInclusive,
     int endExclusive)Returns a sequential ordered  IntStreamfromstartInclusive(inclusive) toendExclusive(exclusive) by an incremental step of1. | 
| static IntStream | rangeClosed(int startInclusive,
           int endInclusive)Returns a sequential ordered  IntStreamfromstartInclusive(inclusive) toendInclusive(inclusive) by an incremental step of1. | 
| OptionalInt | reduce(IntBinaryOperator op)Performs a reduction on the
 elements of this stream, using an
 associative accumulation
 function, and returns an  OptionalIntdescribing the reduced value,
 if any. | 
| int | reduce(int identity,
      IntBinaryOperator op)Performs a reduction on the
 elements of this stream, using the provided identity value and an
 associative
 accumulation function, and returns the reduced value. | 
| IntStream | sequential()Returns an equivalent stream that is sequential. | 
| IntStream | skip(long n)Returns a stream consisting of the remaining elements of this stream
 after discarding the first  nelements of the stream. | 
| IntStream | sorted()Returns a stream consisting of the elements of this stream in sorted
 order. | 
| Spliterator.OfInt | spliterator()Returns a spliterator for the elements of this stream. | 
| int | sum()Returns the sum of elements in this stream. | 
| IntSummaryStatistics | summaryStatistics()Returns an  IntSummaryStatisticsdescribing various
 summary data about the elements of this stream. | 
| int[] | toArray()Returns an array containing the elements of this stream. | 
close, isParallel, onClose, unorderedIntStream filter(IntPredicate predicate)
This is an intermediate operation.
predicate - a non-interfering,
                  stateless
                  predicate to apply to each element to determine if it
                  should be includedIntStream map(IntUnaryOperator mapper)
This is an intermediate operation.
mapper - a non-interfering,
               stateless
               function to apply to each element<U> Stream<U> mapToObj(IntFunction<? extends U> mapper)
Stream consisting of the results of
 applying the given function to the elements of this stream.
 This is an intermediate operation.
U - the element type of the new streammapper - a non-interfering,
               stateless
               function to apply to each elementLongStream mapToLong(IntToLongFunction mapper)
LongStream consisting of the results of applying the
 given function to the elements of this stream.
 This is an intermediate operation.
mapper - a non-interfering,
               stateless
               function to apply to each elementDoubleStream mapToDouble(IntToDoubleFunction mapper)
DoubleStream consisting of the results of applying the
 given function to the elements of this stream.
 This is an intermediate operation.
mapper - a non-interfering,
               stateless
               function to apply to each elementIntStream flatMap(IntFunction<? extends IntStream> mapper)
closed after its contents
 have been placed into this stream.  (If a mapped stream is null
 an empty stream is used, instead.)
 This is an intermediate operation.
mapper - a non-interfering,
               stateless
               function to apply to each element which produces an
               IntStream of new valuesStream.flatMap(Function)IntStream distinct()
This is a stateful intermediate operation.
IntStream sorted()
This is a stateful intermediate operation.
IntStream peek(IntConsumer action)
This is an intermediate operation.
For parallel stream pipelines, the action may be called at whatever time and in whatever thread the element is made available by the upstream operation. If the action modifies shared state, it is responsible for providing the required synchronization.
     IntStream.of(1, 2, 3, 4)
         .filter(e -> e > 2)
         .peek(e -> System.out.println("Filtered value: " + e))
         .map(e -> e * e)
         .peek(e -> System.out.println("Mapped value: " + e))
         .sum();
 action - a 
               non-interfering action to perform on the elements as
               they are consumed from the streamIntStream limit(long maxSize)
maxSize in length.
 limit() is generally a cheap operation on sequential
 stream pipelines, it can be quite expensive on ordered parallel pipelines,
 especially for large values of maxSize, since limit(n)
 is constrained to return not just any n elements, but the
 first n elements in the encounter order.  Using an unordered
 stream source (such as generate(IntSupplier)) or removing the
 ordering constraint with BaseStream.unordered() may result in significant
 speedups of limit() in parallel pipelines, if the semantics of
 your situation permit.  If consistency with encounter order is required,
 and you are experiencing poor performance or memory utilization with
 limit() in parallel pipelines, switching to sequential execution
 with sequential() may improve performance.maxSize - the number of elements the stream should be limited toIllegalArgumentException - if maxSize is negativeIntStream skip(long n)
n elements of the stream.
 If this stream contains fewer than n elements then an
 empty stream will be returned.
 This is a stateful intermediate operation.
skip() is generally a cheap operation on sequential
 stream pipelines, it can be quite expensive on ordered parallel pipelines,
 especially for large values of n, since skip(n)
 is constrained to skip not just any n elements, but the
 first n elements in the encounter order.  Using an unordered
 stream source (such as generate(IntSupplier)) or removing the
 ordering constraint with BaseStream.unordered() may result in significant
 speedups of skip() in parallel pipelines, if the semantics of
 your situation permit.  If consistency with encounter order is required,
 and you are experiencing poor performance or memory utilization with
 skip() in parallel pipelines, switching to sequential execution
 with sequential() may improve performance.n - the number of leading elements to skipIllegalArgumentException - if n is negativevoid forEach(IntConsumer action)
This is a terminal operation.
For parallel stream pipelines, this operation does not guarantee to respect the encounter order of the stream, as doing so would sacrifice the benefit of parallelism. For any given element, the action may be performed at whatever time and in whatever thread the library chooses. If the action accesses shared state, it is responsible for providing the required synchronization.
action - a 
               non-interfering action to perform on the elementsvoid forEachOrdered(IntConsumer action)
This is a terminal operation.
action - a 
               non-interfering action to perform on the elementsforEach(IntConsumer)int[] toArray()
This is a terminal operation.
int reduce(int identity,
           IntBinaryOperator op)
     int result = identity;
     for (int element : this stream)
         result = accumulator.applyAsInt(result, element)
     return result;
 The identity value must be an identity for the accumulator
 function. This means that for all x,
 accumulator.apply(identity, x) is equal to x.
 The accumulator function must be an
 associative function.
 
This is a terminal operation.
     int sum = integers.reduce(0, (a, b) -> a+b);
 
     int sum = integers.reduce(0, Integer::sum);
 While this may seem a more roundabout way to perform an aggregation compared to simply mutating a running total in a loop, reduction operations parallelize more gracefully, without needing additional synchronization and with greatly reduced risk of data races.
identity - the identity value for the accumulating functionop - an associative,
           non-interfering,
           stateless
           function for combining two valuessum(), 
min(), 
max(), 
average()OptionalInt reduce(IntBinaryOperator op)
OptionalInt describing the reduced value,
 if any. This is equivalent to:
 
     boolean foundAny = false;
     int result = null;
     for (int element : this stream) {
         if (!foundAny) {
             foundAny = true;
             result = element;
         }
         else
             result = accumulator.applyAsInt(result, element);
     }
     return foundAny ? OptionalInt.of(result) : OptionalInt.empty();
 The accumulator function must be an
 associative function.
 
This is a terminal operation.
op - an associative,
           non-interfering,
           stateless
           function for combining two valuesreduce(int, IntBinaryOperator)<R> R collect(Supplier<R> supplier, ObjIntConsumer<R> accumulator, BiConsumer<R,R> combiner)
ArrayList, and elements are incorporated by updating
 the state of the result rather than by replacing the result.  This
 produces a result equivalent to:
 
     R result = supplier.get();
     for (int element : this stream)
         accumulator.accept(result, element);
     return result;
 Like reduce(int, IntBinaryOperator), collect operations
 can be parallelized without requiring additional synchronization.
 
This is a terminal operation.
R - type of the resultsupplier - a function that creates a new result container. For a
                 parallel execution, this function may be called
                 multiple times and must return a fresh value each time.accumulator - an associative,
                    non-interfering,
                    stateless
                    function for incorporating an additional element into a resultcombiner - an associative,
                    non-interfering,
                    stateless
                    function for combining two values, which must be
                    compatible with the accumulator functionStream.collect(Supplier, BiConsumer, BiConsumer)int sum()
     return reduce(0, Integer::sum);
 This is a terminal operation.
OptionalInt min()
OptionalInt describing the minimum element of this
 stream, or an empty optional if this stream is empty.  This is a special
 case of a reduction
 and is equivalent to:
 
     return reduce(Integer::min);
 This is a terminal operation.
OptionalInt containing the minimum element of this
 stream, or an empty OptionalInt if the stream is emptyOptionalInt max()
OptionalInt describing the maximum element of this
 stream, or an empty optional if this stream is empty.  This is a special
 case of a reduction
 and is equivalent to:
 
     return reduce(Integer::max);
 This is a terminal operation.
OptionalInt containing the maximum element of this
 stream, or an empty OptionalInt if the stream is emptylong count()
     return mapToLong(e -> 1L).sum();
 This is a terminal operation.
OptionalDouble average()
OptionalDouble describing the arithmetic mean of elements of
 this stream, or an empty optional if this stream is empty.  This is a
 special case of a
 reduction.
 This is a terminal operation.
OptionalDouble containing the average element of this
 stream, or an empty optional if the stream is emptyIntSummaryStatistics summaryStatistics()
IntSummaryStatistics describing various
 summary data about the elements of this stream.  This is a special
 case of a reduction.
 This is a terminal operation.
IntSummaryStatistics describing various summary data
 about the elements of this streamboolean anyMatch(IntPredicate predicate)
false is returned and the predicate is not evaluated.
 This is a short-circuiting terminal operation.
predicate - a non-interfering,
                  stateless
                  predicate to apply to elements of this streamtrue if any elements of the stream match the provided
 predicate, otherwise falseboolean allMatch(IntPredicate predicate)
true is
 returned and the predicate is not evaluated.
 This is a short-circuiting terminal operation.
true (regardless of P(x)).predicate - a non-interfering,
                  stateless
                  predicate to apply to elements of this streamtrue if either all elements of the stream match the
 provided predicate or the stream is empty, otherwise falseboolean noneMatch(IntPredicate predicate)
true is
 returned and the predicate is not evaluated.
 This is a short-circuiting terminal operation.
true, regardless of P(x).predicate - a non-interfering,
                  stateless
                  predicate to apply to elements of this streamtrue if either no elements of the stream match the
 provided predicate or the stream is empty, otherwise falseOptionalInt findFirst()
OptionalInt describing the first element of this
 stream, or an empty OptionalInt if the stream is empty.  If the
 stream has no encounter order, then any element may be returned.
 This is a short-circuiting terminal operation.
OptionalInt describing the first element of this stream,
 or an empty OptionalInt if the stream is emptyOptionalInt findAny()
OptionalInt describing some element of the stream, or
 an empty OptionalInt if the stream is empty.
 This is a short-circuiting terminal operation.
The behavior of this operation is explicitly nondeterministic; it is
 free to select any element in the stream.  This is to allow for maximal
 performance in parallel operations; the cost is that multiple invocations
 on the same source may not return the same result.  (If a stable result
 is desired, use findFirst() instead.)
OptionalInt describing some element of this stream, or
 an empty OptionalInt if the stream is emptyfindFirst()LongStream asLongStream()
LongStream consisting of the elements of this stream,
 converted to long.
 This is an intermediate operation.
LongStream consisting of the elements of this stream,
 converted to longDoubleStream asDoubleStream()
DoubleStream consisting of the elements of this stream,
 converted to double.
 This is an intermediate operation.
DoubleStream consisting of the elements of this stream,
 converted to doubleStream<Integer> boxed()
Stream consisting of the elements of this stream,
 each boxed to an Integer.
 This is an intermediate operation.
Stream consistent of the elements of this stream,
 each boxed to an IntegerIntStream sequential()
BaseStreamThis is an intermediate operation.
sequential in interface BaseStream<Integer,IntStream>IntStream parallel()
BaseStreamThis is an intermediate operation.
parallel in interface BaseStream<Integer,IntStream>PrimitiveIterator.OfInt iterator()
BaseStreamThis is a terminal operation.
iterator in interface BaseStream<Integer,IntStream>Spliterator.OfInt spliterator()
BaseStreamThis is a terminal operation.
spliterator in interface BaseStream<Integer,IntStream>static IntStream.Builder builder()
IntStream.static IntStream empty()
IntStream.static IntStream of(int t)
IntStream containing a single element.t - the single elementstatic IntStream of(int... values)
values - the elements of the new streamstatic IntStream iterate(int seed, IntUnaryOperator f)
IntStream produced by iterative
 application of a function f to an initial element seed,
 producing a Stream consisting of seed, f(seed),
 f(f(seed)), etc.
 The first element (position 0) in the IntStream will be
 the provided seed.  For n > 0, the element at position
 n, will be the result of applying the function f to the
 element at position n - 1.
seed - the initial elementf - a function to be applied to to the previous element to produce
          a new elementIntStreamstatic IntStream generate(IntSupplier s)
IntSupplier.  This is suitable for
 generating constant streams, streams of random elements, etc.s - the IntSupplier for generated elementsIntStreamstatic IntStream range(int startInclusive, int endExclusive)
IntStream from startInclusive
 (inclusive) to endExclusive (exclusive) by an incremental step of
 1.An equivalent sequence of increasing values can be produced
 sequentially using a for loop as follows:
 
     for (int i = startInclusive; i < endExclusive ; i++) { ... }
 startInclusive - the (inclusive) initial valueendExclusive - the exclusive upper boundIntStream for the range of int
         elementsstatic IntStream rangeClosed(int startInclusive, int endInclusive)
IntStream from startInclusive
 (inclusive) to endInclusive (inclusive) by an incremental step of
 1.An equivalent sequence of increasing values can be produced
 sequentially using a for loop as follows:
 
     for (int i = startInclusive; i <= endInclusive ; i++) { ... }
 startInclusive - the (inclusive) initial valueendInclusive - the inclusive upper boundIntStream for the range of int
         elementsstatic IntStream concat(IntStream a, IntStream b)
StackOverflowException.a - the first streamb - the second stream Submit a bug or feature 
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
 Copyright © 1993, 2016, Oracle and/or its affiliates.  All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.