(This book introduces Java threads and concurrency in an easy to understand way. It is a perfect reference manual for Java concurrency. Starting from the basic concepts of concurrency and thread safety, the book introduces how to use the basic concurrency building blocks provided by the class library, the rules for preventing concurrency risks, structuring thread safe classes, and verifying thread safety, how to combine small thread safe classes into larger thread safe classes, how to use threads to improve the throughput of concurrent programs, and how to identify commands that can be performed in parallel, How to improve the responsiveness of the single line program subsystem, how to ensure that the concurrent programs perform the expected commands, how to improve the function and scalability of the concurrent code, and finally introduced some advanced topics, such as explicit locking, atomic variables, non blocking algorithms, and how to develop customized synchronization tool classes.)