I wanted to say a lot about this book but fortunately this guy said it already. This is a very little-understood topic, especially among Pinoy Java Developers. Reading it came at the right time, just when I’m starting to write some real concurrent apps.
This book helps even if you never plan to DIY concurrency, and are happy to rely on app server functionality. If you will never use concurrent or multithreaded Java – doubtful – JCIP is still useful because it helps you understand some Java concepts in a practical setting.
If you haven’t, reading Joshua Bloch’s Effective Java first is recommended.