public class MainActivity extends AppCompatActivity {

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        Log.w("TAG", "----程序开始运行----");

        Date date1 = new Date();

        int taskSize = 2;

        // 创建一个线程池

        ExecutorService pool = Executors.newFixedThreadPool(taskSize);

        // 创建多个有返回值的任务

        List<Future> list = new ArrayList<Future>();

        for (int i = 0; i < taskSize; i++) {

            Callable c = new MyCallable(i + " ");

            // 执行任务并获取Future对象

            Future f = pool.submit(c);

            // System.out.println(">>>" + f.get().toString());

            list.add(f);

        }

        // 关闭线程池

        pool.shutdown();

        // 获取所有并发任务的运行结果

        for (Future f : list) {

            // 从Future对象上获取任务的返回值，并输出到控制台

            try {

                Log.w("TAG", ">----123-->>" + f.get().toString());

            } catch (ExecutionException e) {

                e.printStackTrace();

            } catch (InterruptedException e) {

                e.printStackTrace();

            }

        }

        Date date2 = new Date();

        Log.w("TAG", "----程序结束运行----，程序运行时间【" + (date2.getTime() - date1.getTime()) + "毫秒】");

    }

    }

public class MyCallable implements Callable<Object> {

    private String taskNum;

    public MyCallable(String taskNum) {

        this.taskNum = taskNum;

    }

    public Object call() throws Exception {

        Log.w("TAG", ">call---->>" + taskNum + "任务启动");

        Date dateTmp1 = new Date();

        Thread.sleep(3000);

        Date dateTmp2 = new Date();

        long time = dateTmp2.getTime() - dateTmp1.getTime();

        Log.w("TAG", ">>>" + taskNum + "任务终止");

        return taskNum + "任务返回运行结果,当前任务时间【" + time + "毫秒】";

    }

}