Java Streams 3. Create a Stream

A Stream object can be created in several ways, such as, for example:

— from a Collection using the stream() and parallelStream() methods;

— from an array using Arrays.stream(Object[]);

— from an array or varargs using Stream.of(Object[]);

— using Stream.builder();

— using Stream.generate(Supplier);

— using Stream.iterate(Object, UnaryOperator) or Stream.iterate(T seed, Predicate hasNext, UnaryOperator f);

— using IntStream.range(int, int), IntStream.rangeClosed(int, int) or LongStream.range(long, long), LongStream.rangeClosed(long, long);

— using Files.lines(Path) that creates Stream<String> of lines from the file;

— using Files.list(Path) or Files.walk(Path) that create Stream<Path> of entries in the directory;

— using String class methods chars(), codePoints(), and lines();

— using IntStream Random.ints() or any of its other overloaded versions that create a stream of random ints; also, LongStream Random.longs(), DoubleStream Random.doubles() and their overloads;

— using various other classes of JDK, including IntStream BitSet.stream(), JarFile.stream() (opens in a new tab)”>Stream<JarEntry> JarFile.stream(), and Pattern.splitAsStream(java.lang.CharSequence) (opens in a new tab)”>Stream<String> Pattern.splitAsStream(java.lang.CharSequence), to name a few.

We will discuss each of these methods in the subsequent posts.

See other posts on Java 8 streams and posts on other topics.
You can also use navigation pages for Java stream related blogs:
— Java 8 streams blog titles
— Create stream
— Stream operations
— Stream operation collect()
The source code of all the code examples is here in GitHub.