java - 什么时候使用线程，什么时候使用线程池？

Question

任何人都可以在这个示例中指导我 Thread 和 ThreadPool 它们之间有什么区别？哪个更好用...？缺点是什么？

我使用了一个线程池，为什么在这种情况下使用它 true 或 false ？

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

class ThreeThread implements Runnable {

    String c;
    Semaphore s1;
    Semaphore s2;

    public ThreeThread(String s, Semaphore s1, Semaphore s2) {
        this.c = s;
        this.s1 = s1;
        this.s2 = s2;
    }

    @Override
    public void run() {
        while (true) {
            try {
                s1.acquire();
                Thread.sleep(400);
                System.out.println(c);
                s2.release();
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                System.out.println(e);
            }
        }
    }

    public static void main(String[] args) {
        Semaphore sm1 = new Semaphore(1);
        Semaphore sm2 = new Semaphore(0);
        Semaphore sm3 = new Semaphore(0);

        ExecutorService es = Executors.newFixedThreadPool(3);

        es.execute(new ThreeThread("1", sm1, sm2));
        es.execute(new ThreeThread("2", sm2, sm3));
        es.execute(new ThreeThread("3", sm3, sm1));
    }
}

Answer 1

请参阅 ThreadPoolExecutor 的文档:

Thread pools address two different problems:

they usually provideimproved performance when executing large numbers of asynchronoustasks, due to reduced per-task invocation overhead,

and they provide ameans of bounding and managing the resources, including threads,consumed when executing a collection of tasks.

Each ThreadPoolExecutoralso maintains some basic statistics, such as the number of completedtasks.