Runnable,Callable,Feature用法

@FunctionalInterface
public interface Callable<V> {
    /**
     * Computes a result, or throws an exception if unable to do so.
     *
     * @return computed result
     * @throws Exception if unable to compute a result
     */
    V call() throws Exception;
}

Callable接口支持泛型，传入的泛型是call方法的返回类型

package com.demo.feature;

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.FutureTask;

public class FeatureDemo {

	public static void main(String[] args) throws InterruptedException, ExecutionException {
		ExecutorService es = Executors.newCachedThreadPool();
		Callable<String> callable = new Callable<String>() {
			@Override
			public String call() throws Exception {
				Thread.sleep(3000);
				System.out.println("callable ...");
				return "hello";
			}
		};

		FutureTask<String> futureTask = new FutureTask<String>(callable);
		es.submit(futureTask);
		System.out.println("get callable ...");

		while (true) {
			if (futureTask.isDone()) {
				System.out.println("thread done ...");
				String result = futureTask.get();
				System.out.println("result:" + result);
				break;
			} else {
				System.out.println("thread running ...");
				Thread.sleep(500);
			}
		}

	}

}