原创：转载需注明原创地址 https://www.cnblogs.com/fanerwei222/p/11871911.html

public static void main(String[] args) throws InterruptedException, ExecutionException {

    ExecutorService executorService = Executors.newFixedThreadPool(5);

    /**

     * 接口

     */

    CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(executorService);

    completionService.submit(() -> 1);

    /**

     * take()方法 取来 Future, 阻塞型的

     * Future.get()方法获取返回结果

     */

    completionService.take().get();

    /**

     * 接口

     */

    CompletionStage completionStage = null;

    /**

     * CompletionStage/Future 的实现类

     */

    CompletableFuture completableFuture = null;

}