Can a stream be passed as a parameter to Stream API methods?

In Java Stream API, you cannot directly pass a stream (Stream) as a parameter to methods that expect collections or arrays, but you can pass the Stream object itself as a method parameter if the method accepts a Stream.

However, it is important to remember that streams in Java are single-use — after a terminal operation is performed, the stream is closed and cannot be reused.

Example of passing a Stream to a method:

public void processStream(Stream<String> stream) {
    stream.filter(s -> s.startsWith("A"))
          .forEach(System.out::println);
}

// Call
Stream<String> myStream = Stream.of("Apple", "Banana", "Avocado");
processStream(myStream);

If the method expects a collection, you can pass the collection, and create a stream inside the method.

Thus, a stream can be passed as a parameter if the method supports it, but the same stream cannot be used multiple times, and you cannot pass a stream where a collection or array is expected without conversion.