I have recently started to work on writing a short practical guide that teaches how to develop Java applications for the android platform. You can find it at www.AndroidBook.co.il.

Stable Values in Java (JEP 502): Deferred Immutability with JVM Trust
Explore Stable Values – a new Java 25 upcoming feature (JEP 502) enabling lazy initialization with immutable performance and JVM-level optimizations.