Creating a stream

There are many ways to create a stream—an object of the Stream type or any of the numeric interfaces. We have grouped them by classes and interfaces that have methods creating Stream objects. We did so for the reader's convenience, to provide a better overview, so that it will be easier for the reader to find them if needed.

Stream interface

This group of Stream factories is composed of static methods that belong to the Stream interface.

empty(), of(T t), ofNullable(T t)

The following three methods create either empty or single-element Stream objects: 

• Stream<T> empty(): Creates an empty sequential Stream object.
• Stream<T> of(T t): Creates a sequential single-element Stream object.
• Stream<T> ofNullable(T t): Creates a sequential Stream object containing a single element if the t parameter is non-null; otherwise, creates an empty Stream.

The following code demonstrates the usage of the preceding methods:

Stream.empty().forEach(System.out::println);    //prints nothing...