import java.util.Date;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;

public class ExecutorTest4 {
    public ExecutorTest4() {
        ExecutorService e = Executors.newSingleThreadExecutor();

        Future<Date> future = e.submit(new CallableTask());
        System.out.println("CallableTask is Called");
        System.out.println("Future#isDone(): " + future.isDone());

        try {
            System.out.println("Future#get(): " + future.get());
            System.out.println("Future#isDone(): " + future.isDone());
        } catch (ExecutionException ex) {
            ex.printStackTrace();
        } catch (InterruptedException ex) {
            ex.printStackTrace();
        }

        e.shutdown();
    }

    class CallableTask implements Callable<Date> {
        public Date call() {
            try {
                Thread.sleep(1000L);
            } catch (InterruptedException ex) {
                System.out.println("CallableTask is Canceled");
                return null;
            }

            System.out.println("CallableTask is Done.");
            return new Date();
        }
    }

    public static void main(String[] args) {
        new ExecutorTest4();
    }
}