如何在 Java 中创建一个空的 Stream？

As simple as this: Stream.empty()

Stream<String> emptyStr = Stream.of();

emptyStr.count() returns 0 (zero).

In addition:

• For a primitive stream like IntStream, IntStream.of() works in similar way (also the empty method). IntStream.of(new int[]{}) also returns an empty stream.
• The Arrays class has stream creation methods which accept an array of primitives or an object type. This can be used to create an empty stream; e.g.,: System.out.println(Arrays.stream(new int[]{}).count()); prints zero.
• Any stream created from a collection (like a List or Set) with zero elements can return an empty stream; for example: new ArrayList<Integer>().stream() returns an empty stream of type Integer.