What is a thread pool?

1 Thread pool

Pool thought Thread pool String constant pool Database connection pool

Improve resource utilization

1 Create thread objects manually

2 Perform tasks

3 completion of enforcement Release thread object .

Waiting in line

advantage

Improve thread utilization

Improve the response speed of the program

Easy to manage Thread objects in a unified way

Control the maximum concurrent number

Emergency response plan

Create a new thread

It is impossible to create thread objects indefinitely （ Maximum number of threads ）

Refuse —

Business hall of analogy bank

Additional code

public class Test {
    
    public static void main(String[] args) {
    
        ExecutorService executorService = new ThreadPoolExecutor(3, 5, 1L, TimeUnit.SECONDS, new ArrayBlockingQueue<>(3), Executors.defaultThreadFactory(), new ThreadPoolExecutor.AbortPolicy());
        for(int i=0;i<8;i++){
    
            executorService.execute(()->{
    
                System.out.println(Thread.currentThread().getName()+"===> Handle the business ");
            });
        }
        executorService.shutdown();
    }
}