Streams:
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java.util.stream package (Streams),which enables the concise and declarative expression of possibly-parallel bulk operations on various data sources.
All stream computations share a common structure: They have a stream source, zero or moreintermediate operations, and a single terminal operation.
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Method
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Description
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Collection.stream()
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Create a stream from the elements of a collection.
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Stream.of(T...)
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Create a stream from the arguments passed to the factory method.
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Stream.of(T[])
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Create a stream from the elements of an array.
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Stream.empty()
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Create an empty stream.
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Stream.iterate(T first, BinaryOperator<T> f)
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Create an infinite stream consisting of the sequence first,
f(first), f(f(first)), ... |
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Stream.iterate(T first, Predicate<T> test,
BinaryOperator<T> f) |
(Java 9 only) Similar to Stream.iterate(T first,
BinaryOperator<T> f), except the stream terminates on the first elements for which the test predicate returns false. |
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Stream.generate(Supplier<T> f)
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Create an infinite stream from a generator function.
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IntStream.range(lower, upper)
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Create an IntStream consisting of the elements from lower to upper,
exclusive. |
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IntStream.rangeClosed(lower, upper)
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Create an IntStream consisting of the elements from lower to upper,
inclusive. |
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BufferedReader.lines()
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Create a stream consisting of the lines from a BufferedReader.
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BitSet.stream()
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Create an IntStream consisting of the indexes of the set bits in a
BitSet. |
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CharSequence.chars()
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Create an IntStream corresponding to the chars in a String.
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Intermediate operations :-
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Operation
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Contents
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filter(Predicate<T>)
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The elements of the stream matching the predicate
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map(Function<T, U>)
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The result of applying the provided function to the elements of the
stream |
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flatMap(Function<T, Stream<U>>
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The elements of the streams resulting from applying the provided
stream-bearing function to the elements of the stream |
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distinct()
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The elements of the stream, with duplicates removed
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sorted()
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The elements of the stream, sorted in natural order
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Sorted(Comparator<T>)
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The elements of the stream, sorted by the provided comparator
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limit(long)
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The elements of the stream, truncated to the provided length
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skip(long)
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The elements of the stream, discarding the first N elements
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takeWhile(Predicate<T>)
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(Java 9 only) The elements of the stream, truncated at the first element
for which the provided predicate is not true |
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dropWhile(Predicate<T>)
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(Java 9 only) The elements of the stream, discarding the initial segment
of elements for which the provided predicate is true |
Terminal stream operations:-
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Operation
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Description
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forEach(Consumer<T> action)
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Apply the provided action to each element of the stream.
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toArray()
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Create an array from the elements of the stream.
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reduce(...)
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Aggregate the elements of the stream into a summary value.
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collect(...)
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Aggregate the elements of the stream into a summary result container.
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min(Comparator<T>)
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Return the minimal element of the stream according to the comparator.
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max(Comparator<T>)
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Return the maximal element of the stream according to the comparator.
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count()
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Return the size of the stream.
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{any,all,none}Match(Predicate<T>)
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Return whether any/all/none of the elements of the stream match the
provided predicate. |
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findFirst()
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Return the first element of the stream, if present.
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findAny()
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Return any element of the stream, if present.
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