jdk自带future和netty的future入门demo

netty的future继承自jdk的future。但netty的future可以异步获取结果，而jdk自带的future只能同步阻塞拿到结果。下面是代码展示：

@Slf4j
public class TestJdkFuture {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        //1先得到一个线程池
        ExecutorService service = Executors.newFixedThreadPool(2);
        //2提交任务
        Future future = service.submit(new Callable() {
            @Override
            public Integer call() throws Exception {
                log.debug("========执行计算");
                Thread.sleep(1000);
                return 50;
            }
        });

        //3主线程通过future来获取结果 future.get()方法会阻塞直到拿到结果
        log.debug("=====等待结果");
        log.debug("===结果是：{}",future.get());

    }

}

```java

@Slf4j
public class TestNettyFuture {
    public static void main(String[] args) throws ExecutionException, InterruptedException {

        NioEventLoopGroup group = new NioEventLoopGroup();
        EventLoop next = group.next();
        Future future = next.submit(new Callable() {
            @Override
            public Integer call() throws Exception {
                log.debug("========执行计算");
                Thread.sleep(1000);
                return 70;
            }
        });

        //3主线程通过future来获取结果 future.get()方法会阻塞直到拿到结果
        

        future.addListener(new GenericFutureListener>() {
            @Override
            public void operationComplete(Future future) throws Exception {
                log.debug("=====接收结果{}",future.getNow());
            }
        });
    }
}

netty的future可以调用future.addListener()方法添加监听，异步获取结果。