What are the basic classes and interfaces for working with threads in Java?

In Java, for working with streams in the java.util.stream package, there are key interfaces and classes:

• Stream<T> — the main interface for sequential processing of elements. It allows filtering, transforming, sorting, and aggregating operations.
• IntStream, LongStream, DoubleStream — specialized interfaces for working with primitive types to avoid auto-boxing.
• Collectors — a class with static methods for collecting stream elements into collections, strings, maps, etc.
• StreamSupport — a class for creating streams from sources that support Spliterator.

Common methods for creating streams include:

• Collection.stream() — to obtain a sequential stream from a collection.
• Collection.parallelStream() — for a parallel stream.

Example usage:

List<String> list = Arrays.asList("a", "b", "c");
Stream<String> stream = list.stream();
List<String> upper = stream.map(String::toUpperCase).collect(Collectors.toList());

Also, for multithreading in Java, there is the Thread class and the Runnable interface, but these are about parallel execution, not specifically about the Stream API.