The recipes in this book assume that the typical reader already is comfortable with Java versions prior to Java SE 8. You don’t need to be an expert, and some older con‐ cepts are reviewed, but the book is not intended to be a beginner’s guide to Java or object-oriented programming. If you have used Java on a project before and you are familiar with the standard library, you’ll be fine.
This book covers almost all of Java SE 8, and includes one chapter focused on the new changes coming in Java 9. If you need to understand how the new functional idioms added to the language will change the way you write code, this book is a use-casedriven way of accomplishing that goal.
Java is pervasive on the server side, with a rich support system of open source libra‐ ries and tools. The Spring Framework and Hibernate are two of the most popular open source frameworks, and both either require Java 8 as a minimum or will very soon. If you plan to operate in this ecosystem, this book is for you.