Java线程池，isShutDown、isTerminated的作用与区别

isShutDown当调用shutdown()或shutdownNow()方法后返回为true。 
isTerminated当调用shutdown()方法后，并且所有提交的任务完成后返回为true;
isTerminated当调用shutdownNow()方法后，成功停止后返回为true;
如果线程池任务正常完成，都为false

import java.util.concurrent.Callable;

public class ShortTask implements Callable {
    @Override
    public Object call() throws Exception {
        System.out.println("短任务");
        return null;
    }
}

import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;

public class LongTask implements Callable {
    @Override
    public Object call() throws Exception {
        System.out.println("长任务");
        TimeUnit.SECONDS.sleep(5);
        return null;
    }
}

　　

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class Main {

    public static void main(String[] args) {
        ScheduledExecutorService service = Executors.newScheduledThreadPool(4);
        service.submit(new ShortTask());
        service.submit(new ShortTask());
        service.submit(new LongTask());
        service.submit(new ShortTask());
        System.out.println("isShutdown:" + service.isShutdown());
        System.out.println("isTerminated:" + service.isTerminated());
        service.shutdown();
//        List<Runnable> list = service.shutdownNow();
//        System.out.println(list.size());
        System.out.println("isShutdown:" + service.isShutdown());
        System.out.println("isTerminated:" + service.isTerminated());
        try {
            while (!service.awaitTermination(1, TimeUnit.SECONDS)) {
                System.out.println("线程池没有关闭");
                System.out.println("isTerminated:" + service.isTerminated());
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        System.out.println("线程池已经关闭");
        System.out.println("isTerminated:" + service.isTerminated());
    }
}

　　

/*
执行service.shutdown();
短任务
短任务
长任务
短任务
isShutdown:false
isTerminated:false
isShutdown:true
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池已经关闭
isTerminated:true*/

/*
执行List<Runnable> list = service.shutdownNow();
System.out.println(list.size());
短任务
短任务
长任务
isShutdown:false
isTerminated:false
1
isShutdown:true
isTerminated:false
线程池已经关闭
isTerminated:true
*/

/*
如果不执行shutdown，也不执行shutdownNow：
短任务
短任务
长任务
短任务
isShutdown:false
isTerminated:false
isShutdown:false
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
线程池没有关闭
isTerminated:false
......一直这样输出
*/