Introduction to Programming

The Stream.Builder interface

The Stream.Builder<T> builder() static method returns an internal (located inside the interface Stream interface) Builder interface that can be used to construct a Stream object. The Builder interface extends the Consumer interface, and has the following methods:

• void accept(T t): Adds an element to the stream (this method comes from the Consumer interface).
• default Stream.Builder<T> add(T t): Calls the accept(T) method and returns this, thus allowing chaining add(T) methods in a fluent, dot-connected style.
• Stream<T> build(): Transitions this builder from the constructing state to the built state. After this method is called, no new elements can be added to the stream.

Using the add() method is straightforward: ...