import java.util.concurrent.*;
public class FutureCallableDemo
{
  static long fibonacci(long n)
  {
    if (n == 1 ||n == 2)
      return 1;
    else
      return fibonacci(n - 1) + fibonacci(n - 2);
  }
  public static void main( String[] args) throws Exception
  {
    Callable<Long> task = () -> fibonacci(30);
    ExecutorService executor = Executors.newFixedThreadPool(1);
    Future<Long> future = executor.submit(task);
    System.out.println("計算第10個斐波那契級數(shù)，過會來取...") ;
    while (future.isDone() == false)
    {
      System.out.println("忙別的去吧，結果還在計算中...") ;
    }
    System.out.printf("計算完畢，第10個斐波那契級數(shù)是:%d %n", future.get()) ;
  }
}

import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
class Task implements Runnable
{
  private String name;
  public Task(String name)
  {
    this.name = name;
  }
  public String getName() {
    return name;
  }
  @Override
  public void run()
  {
    try
    {
      Long duration = (long) (Math.random() * 100);
      System.out.println("正在做工中，執(zhí)行者 : " + name);
      TimeUnit.SECONDS.sleep(duration);
    }
    catch (InterruptedException e)
    {
      e.printStackTrace();
    }
  }
}
public class BasicThreadPoolExecutorExample
{
  public static void main(String[] args)
  {
    ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newCachedThreadPool();
    for (int i = 0; i <= 5; i++)
    {
      Task task = new Task("Task " + i);
      System.out.println("新任務添加成功 : " + task.getName());
      executor.execute(task);
    }
    executor.shutdown();
  }
}