- Java 8 in Action / Modern Java in Action (Raoul-Gabriel Urma, Alan Mycroft, Mario Fusco; 2014 and 2018 respectively)
- The Well-Grounded Java Developer (Martijn Verburg, Benjamin Evans, Jason Clark; 2022) - not specifically focused on new features but does cover them in the context of going deeper into Java and the JVM.
- https://github.com/wesleyegberto/java-new-features (terse, includes links to JEPs, good jumping off point)
- https://github.com/winterbe/java8-tutorial (quick tour through features of Java 8)
- https://winterbe.com/posts/2018/09/24/java-11-tutorial/ (same for Java 11)
Books:
- Java 8 in Action / Modern Java in Action (Raoul-Gabriel Urma, Alan Mycroft, Mario Fusco; 2014 and 2018 respectively)
- The Well-Grounded Java Developer (Martijn Verburg, Benjamin Evans, Jason Clark; 2022) - not specifically focused on new features but does cover them in the context of going deeper into Java and the JVM.