public interface LongStream extends BaseStream<Long,LongStream>
long primitive specialization of
 Stream.
 The following example illustrates an aggregate operation using
 Stream and LongStream, computing the sum of the weights of the
 red widgets:
 
     long sum = widgets.stream()
                       .filter(w -> w.getColor() == RED)
                       .mapToLong(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  | LongStream.BuilderA mutable builder for a  LongStream. | 
| Modifier and Type | Method and Description | 
|---|---|
| boolean | allMatch(LongPredicate predicate)Returns whether all elements of this stream match the provided predicate. | 
| boolean | anyMatch(LongPredicate 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. | 
| OptionalDouble | average()Returns an  OptionalDoubledescribing the arithmetic mean of elements of
 this stream, or an empty optional if this stream is empty. | 
| Stream<Long> | boxed()Returns a  Streamconsisting of the elements of this stream,
 each boxed to aLong. | 
| static LongStream.Builder | builder()Returns a builder for a  LongStream. | 
| <R> R | collect(Supplier<R> supplier,
       ObjLongConsumer<R> accumulator,
       BiConsumer<R,R> combiner)Performs a mutable
 reduction operation on the elements of this stream. | 
| static LongStream | concat(LongStream a,
      LongStream 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. | 
| LongStream | distinct()Returns a stream consisting of the distinct elements of this stream. | 
| static LongStream | empty()Returns an empty sequential  LongStream. | 
| LongStream | filter(LongPredicate predicate)Returns a stream consisting of the elements of this stream that match
 the given predicate. | 
| OptionalLong | findAny()Returns an  OptionalLongdescribing some element of the stream, or
 an emptyOptionalLongif the stream is empty. | 
| OptionalLong | findFirst()Returns an  OptionalLongdescribing the first element of this
 stream, or an emptyOptionalLongif the stream is empty. | 
| LongStream | flatMap(LongFunction<? extends LongStream> 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(LongConsumer action)Performs an action for each element of this stream. | 
| void | forEachOrdered(LongConsumer 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 LongStream | generate(LongSupplier s)Returns an infinite sequential unordered stream where each element is
 generated by the provided  LongSupplier. | 
| static LongStream | iterate(long seed,
       LongUnaryOperator f)Returns an infinite sequential ordered  LongStreamproduced by iterative
 application of a functionfto an initial elementseed,
 producing aStreamconsisting ofseed,f(seed),f(f(seed)), etc. | 
| PrimitiveIterator.OfLong | iterator()Returns an iterator for the elements of this stream. | 
| LongStream | limit(long maxSize)Returns a stream consisting of the elements of this stream, truncated
 to be no longer than  maxSizein length. | 
| LongStream | map(LongUnaryOperator mapper)Returns a stream consisting of the results of applying the given
 function to the elements of this stream. | 
| DoubleStream | mapToDouble(LongToDoubleFunction mapper)Returns a  DoubleStreamconsisting of the results of applying the
 given function to the elements of this stream. | 
| IntStream | mapToInt(LongToIntFunction mapper)Returns an  IntStreamconsisting of the results of applying the
 given function to the elements of this stream. | 
| <U> Stream<U> | mapToObj(LongFunction<? extends U> mapper)Returns an object-valued  Streamconsisting of the results of
 applying the given function to the elements of this stream. | 
| OptionalLong | max()Returns an  OptionalLongdescribing the maximum element of this
 stream, or an empty optional if this stream is empty. | 
| OptionalLong | min()Returns an  OptionalLongdescribing the minimum element of this
 stream, or an empty optional if this stream is empty. | 
| boolean | noneMatch(LongPredicate predicate)Returns whether no elements of this stream match the provided predicate. | 
| static LongStream | of(long... values)Returns a sequential ordered stream whose elements are the specified values. | 
| static LongStream | of(long t)Returns a sequential  LongStreamcontaining a single element. | 
| LongStream | parallel()Returns an equivalent stream that is parallel. | 
| LongStream | peek(LongConsumer 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 LongStream | range(long startInclusive,
     long endExclusive)Returns a sequential ordered  LongStreamfromstartInclusive(inclusive) toendExclusive(exclusive) by an incremental step of1. | 
| static LongStream | rangeClosed(long startInclusive,
           long endInclusive)Returns a sequential ordered  LongStreamfromstartInclusive(inclusive) toendInclusive(inclusive) by an incremental step of1. | 
| OptionalLong | reduce(LongBinaryOperator op)Performs a reduction on the
 elements of this stream, using an
 associative accumulation
 function, and returns an  OptionalLongdescribing the reduced value,
 if any. | 
| long | reduce(long identity,
      LongBinaryOperator 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. | 
| LongStream | sequential()Returns an equivalent stream that is sequential. | 
| LongStream | skip(long n)Returns a stream consisting of the remaining elements of this stream
 after discarding the first  nelements of the stream. | 
| LongStream | sorted()Returns a stream consisting of the elements of this stream in sorted
 order. | 
| Spliterator.OfLong | spliterator()Returns a spliterator for the elements of this stream. | 
| long | sum()Returns the sum of elements in this stream. | 
| LongSummaryStatistics | summaryStatistics()Returns a  LongSummaryStatisticsdescribing various summary data
 about the elements of this stream. | 
| long[] | toArray()Returns an array containing the elements of this stream. | 
close, isParallel, onClose, unorderedLongStream filter(LongPredicate predicate)
This is an intermediate operation.
predicate - a non-interfering,
                  stateless
                  predicate to apply to each element to determine if it
                  should be includedLongStream map(LongUnaryOperator mapper)
This is an intermediate operation.
mapper - a non-interfering,
               stateless
               function to apply to each element<U> Stream<U> mapToObj(LongFunction<? 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 elementIntStream mapToInt(LongToIntFunction mapper)
IntStream 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(LongToDoubleFunction 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 elementLongStream flatMap(LongFunction<? extends LongStream> 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 a
               LongStream of new valuesStream.flatMap(Function)LongStream distinct()
This is a stateful intermediate operation.
LongStream sorted()
This is a stateful intermediate operation.
LongStream peek(LongConsumer 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.
     LongStream.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 streamLongStream 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(LongSupplier)) 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 negativeLongStream 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(LongSupplier)) 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(LongConsumer 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(LongConsumer action)
This is a terminal operation.
action - a 
               non-interfering action to perform on the elementsforEach(LongConsumer)long[] toArray()
This is a terminal operation.
long reduce(long identity,
            LongBinaryOperator op)
     long result = identity;
     for (long element : this stream)
         result = accumulator.applyAsLong(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.
     long sum = integers.reduce(0, (a, b) -> a+b);
 
     long sum = integers.reduce(0, Long::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()OptionalLong reduce(LongBinaryOperator op)
OptionalLong describing the reduced value,
 if any. This is equivalent to:
 
     boolean foundAny = false;
     long result = null;
     for (long element : this stream) {
         if (!foundAny) {
             foundAny = true;
             result = element;
         }
         else
             result = accumulator.applyAsLong(result, element);
     }
     return foundAny ? OptionalLong.of(result) : OptionalLong.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(long, LongBinaryOperator)<R> R collect(Supplier<R> supplier, ObjLongConsumer<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 (long element : this stream)
         accumulator.accept(result, element);
     return result;
 Like reduce(long, LongBinaryOperator), 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)long sum()
     return reduce(0, Long::sum);
 This is a terminal operation.
OptionalLong min()
OptionalLong 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(Long::min);
 This is a terminal operation.
OptionalLong containing the minimum element of this
 stream, or an empty OptionalLong if the stream is emptyOptionalLong max()
OptionalLong 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(Long::max);
 This is a terminal operation.
OptionalLong containing the maximum element of this
 stream, or an empty OptionalLong if the stream is emptylong count()
     return map(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 emptyLongSummaryStatistics summaryStatistics()
LongSummaryStatistics describing various summary data
 about the elements of this stream.  This is a special case of a
 reduction.
 This is a terminal operation.
LongSummaryStatistics describing various summary data
 about the elements of this streamboolean anyMatch(LongPredicate 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(LongPredicate 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(LongPredicate 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 falseOptionalLong findFirst()
OptionalLong describing the first element of this
 stream, or an empty OptionalLong 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.
OptionalLong describing the first element of this
 stream, or an empty OptionalLong if the stream is emptyOptionalLong findAny()
OptionalLong describing some element of the stream, or
 an empty OptionalLong 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.)
OptionalLong describing some element of this stream,
 or an empty OptionalLong if the stream is emptyfindFirst()DoubleStream 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<Long> boxed()
Stream consisting of the elements of this stream,
 each boxed to a Long.
 This is an intermediate operation.
Stream consistent of the elements of this stream,
 each boxed to LongLongStream sequential()
BaseStreamThis is an intermediate operation.
sequential in interface BaseStream<Long,LongStream>LongStream parallel()
BaseStreamThis is an intermediate operation.
parallel in interface BaseStream<Long,LongStream>PrimitiveIterator.OfLong iterator()
BaseStreamThis is a terminal operation.
iterator in interface BaseStream<Long,LongStream>Spliterator.OfLong spliterator()
BaseStreamThis is a terminal operation.
spliterator in interface BaseStream<Long,LongStream>static LongStream.Builder builder()
LongStream.static LongStream empty()
LongStream.static LongStream of(long t)
LongStream containing a single element.t - the single elementstatic LongStream of(long... values)
values - the elements of the new streamstatic LongStream iterate(long seed, LongUnaryOperator f)
LongStream 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 LongStream 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 elementLongStreamstatic LongStream generate(LongSupplier s)
LongSupplier.  This is suitable for
 generating constant streams, streams of random elements, etc.s - the LongSupplier for generated elementsLongStreamstatic LongStream range(long startInclusive, long endExclusive)
LongStream 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 (long i = startInclusive; i < endExclusive ; i++) { ... }
 startInclusive - the (inclusive) initial valueendExclusive - the exclusive upper boundLongStream for the range of long
         elementsstatic LongStream rangeClosed(long startInclusive, long endInclusive)
LongStream 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 (long i = startInclusive; i <= endInclusive ; i++) { ... }
 startInclusive - the (inclusive) initial valueendInclusive - the inclusive upper boundLongStream for the range of long
         elementsstatic LongStream concat(LongStream a, LongStream 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.
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