The Java thread pool consists of 4 parts. The working principle of the thread pool is in the producer-consumer mode
(1) Thread Pool Manager (ThreadPool): is responsible for creating and destroying the thread pool
(2) Worker thread (PoolWorker): it is a thread in the thread pool
(3) Task (Task): this is the thread pool The business code that a thread needs to execute, this is the business logic you write yourself
(4) Task Queue (TaskQueue): This is the task thrown into the thread pool that needs to be queued and needs to be entered into the task queue
