If you're just getting to Java 8, I definitely recommend@adamldavis' book -- very concise and helpful. -Fred Jonsson
Java 8 is a giant step forward for the Java language. In Project Lambda, Java gets a new closure syntax (lambda expressions), method-references, and default and static methods on interfaces. It manages to add many of the features of functional languages without losing the clarity and simplicity Java developers have come to expect. In addition, many of the existing Java core library classes have been enhanced with the new Streams API.
This ebook will help you understand Java 8, including: Project Lambda, the new Date-Time API, Streams, default methods, Nashorn, and more.
This book is 100% complete and available in print here and other places.
If you like this, please check out Adam's other books: Learning Groovy, Modern Java Second Edition, and Modern Programming Made Easy.
10% of all proceeds go directly to the Electronic Frontier Foundation (EFF).
Disclaimer: Java is a registered trademark of Oracle. You can find Java here on Oracle's website.