ThreadPoolExecutor

Posted 2020-09-01

 1 package concurrency;
 2 
 3 import java.util.List;
 4 import java.util.concurrent.BlockingQueue;
 5 import java.util.concurrent.Callable;
 6 import java.util.concurrent.ExecutionException;
 7 import java.util.concurrent.Future;
 8 import java.util.concurrent.LinkedBlockingQueue;
 9 import java.util.concurrent.ThreadPoolExecutor;
10 import java.util.concurrent.TimeUnit;
11 
12 public class ThreadPoolTest {
13     //定义任务队列
14     private static BlockingQueue<Runnable> workQueue =new LinkedBlockingQueue<Runnable>();
15     //创建线程池
16     private static ThreadPoolExecutor executor =
17             new ThreadPoolExecutor(10, 25, 1000000, TimeUnit.NANOSECONDS, workQueue);
18     public static void main(String[] args) throws InterruptedException, ExecutionException {
19         //execute()方法用于提交不需要返回值的任务
20         executor.execute(new ThreadPoolJob());
21         
22         //submit 方法用于提交需要返回值的任务
23         executor.submit(new ThreadPoolJob());//可以提交Runnable类型的job
24         
25         Future<String> future = executor.submit(new ThreadPoolCalJob());//也可以提交Callable类型的job
26         String result = future.get();//Future.get()会一直阻塞到job完成并返回结果
27         
28         System.out.println("result=" + result);
29         
30         executor.shutdown();//将线程池状态设置为shutdown，并中断所有没有正在执行任务的线程
31         
32         //List<Runnable> jobs = executor.shutdownNow();//将线程池的状态设置为stoped，并尝试停止所有正在执行或者暂停任务的线程，并返回等待执行任务的列表
33     }
34     
35 }
36 class ThreadPoolJob implements Runnable{
37 
38     @Override
39     public void run() {
40         System.out.println("i am a runnable..");
41     }
42     
43 }
44 
45 class ThreadPoolCalJob implements Callable<String>{
46 
47     @Override
48     public String call() throws Exception {
49         System.out.println("submit a callable");
50         Thread.sleep(3000);
51         return "ThreadPoolCalJob return a callable";
52     }
53     
54 }