import java.util.concurrent.*;
/**
 * Description:
 * <br/>Copyright (C), 2008-2010, Yeeku.H.Lee
 * <br/>This program is protected by copyright laws.
 * <br/>Program Name:
 * <br/>Date:
 * @author  Yeeku.H.Lee kongyeeku@163.com
 * @version  1.0
 */

class RtnThread implements Callable<Integer>
{
	//實現call方法，作為線程執行體
	public Integer call()
	{
		int i = 0;
		for ( ; i < 100 ; i++ )
		{
			System.out.println(Thread.currentThread().getName()
				+ " 的循環變量i的值：" + i);
		}
		//call()方法可以有返回值
		return i;
	}
} 

public class CallableTest
{
	public static void main(String[] args) 
	{
		//創建Callable對象
		RtnThread rt = new RtnThread();
		//使用FutureTask來包裝Callable對象
		FutureTask<Integer> task = new FutureTask<Integer>(rt);
		for (int i = 0 ; i < 100 ; i++)
		{
			System.out.println(Thread.currentThread().getName()
				+ " 的循環變量i的值：" + i);
			if (i == 20)
			{
				//實質還是以Callable對象來創建、并啟動線程
				new Thread(task , "有返回值的線程").start();
			}
		}
		try
		{
			//獲取線程返回值
			System.out.println("子線程的返回值：" + task.get());					
		}
		catch (Exception ex)
		{
			ex.printStackTrace();
		}
	}
}