Java 8 Black Book is a solid introductory reference that has been written from the experts point of view and so includes hundreds of examples covering every feature of the subject. The book takes you in the direction of mastering the entire spectrum of Java 8 - from generics to security enhancements, from new applet deployment enhancements to networking, from multiple threads to JavaBeans, from JDBC to file handling and much more
An excellent introductory reference that covers not only the basic concepts of Java, but also associated toolkits such as AWT and Swing. An useful and pratical book. The only criticism that I have is that Java FX is not covered in detail, but that is a very small minus.