A Concise Tutorial on Java 8

A Concise Tutorial on Java 8 originates from Benjamin Winterberg's long English article Modern Java - A Guide to Java 8 (published in March 2014); the Chinese version was translated by Huang Xiaofei of the ImportNew community and later circulated widely online as an electronic document and across multiple platforms. The book does not aim to be comprehensive; instead, through code examples plus brief explanations, it demonstrates item by item the language and API changes brought by Java 8: adding default implementations to interfaces with the default keyword, lambda expressions and functional interfaces, method and constructor references, repeatable annotations, and more; the latter half turns to new APIs, covering intermediate and terminal operations of Stream, the functional interface system, the extended methods of Map, and the entirely new java.time date-time API. The author states his position at the outset: Java has not declined, and Java 8 gives the language functional-style expressive power. There is almost no lengthy theory; most of the text is a short runnable code snippet with one or a few comments, so readers can type along, modify, and see the results. Because the book is small and its updates depend on the author's blog and community translations, it is more a quick overview of new features readable in one or two evenings, suited to developers who already write Java 6/7 and want to migrate old code to Java 8 style as soon as possible, not to complete beginners as a first Java textbook.