Instruct: Classify Amazon reviews into positive or negative sentiment
Query: bad introductory book on Java Threads

This book doesn't explain the threading concept. It has a few introductory chapters that explains how to create and spawn a new thread. The rest is examples of using threads. May be this book is intended for Java programmers who already know thread and want know the use of it. If you want to learn thread, I would recomend buying "Jav Thread Programming" from Paul Hyde.