Welcome to my introduction to[Java 8](https://jdk8.java.net/). This tutorial guides you step by step through all new language features. Backed by short and simple code samples you'll learn how to use default interface methods, lambda expressions, method references and repeatable annotations. At the end of the article you'll be familiar with the most recent[API](http://download.java.net/jdk8/docs/api/) changes like streams, functional interfaces, map extensions and the new Date API.**No walls of text, just a bunch of commented code snippets. Enjoy!**

This article was originally posted on[my blog](http://winterbe.com/posts/2014/03/16/java-8-tutorial/). You should[follow me on Twitter](https://twitter.com/winterbe_).

This article was originally posted on[my blog](http://winterbe.com/posts/2014/03/16/java-8-tutorial/). You should**[follow me on Twitter](https://twitter.com/winterbe_)** and check out my new project**[Sequency](https://github.com/winterbe/sequency)**.

A`java.util.Stream` represents a sequence of elements on which one or more operations can be performed. Stream operations are either_intermediate_ or_terminal_. While terminal operations return a result of a certain type, intermediate operations return the stream itself so you can chain multiple method calls in a row. Streams are created on a source, e.g. a`java.util.Collection` like lists or sets (maps are not supported). Stream operations can either be executed sequentially or parallely.

Let's first look how sequential streams work. First we create a sample source in form of a list of strings: