CompletableFuture 延时执行任务

倚栏听风雨2025-08-21 14:32
java 复制代码
public class TestMain {
    private static   ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
    public static void main(String[] args) {
        CompletableFuture<String> future = delayedFuture(() -> {
            try {
                Thread.sleep(3000L);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            return "hello world";
        }, 3, TimeUnit.SECONDS);

        future.whenComplete((result, throwable) -> {
            if (throwable == null) {
                System.out.println(result);
            } else {
                System.out.println(throwable.getMessage());
            }
        });
        try {
            Thread.sleep(10000L);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        int i = 0;
    }


    public static <T> CompletableFuture<T> delayedFuture(Supplier<T> supplier, long delay, TimeUnit unit) {
        CompletableFuture<T> future = new CompletableFuture<>();
        scheduler.schedule(() -> {
            try {
                future.complete(supplier.get());
            } catch (Exception e) {
                future.completeExceptionally(e);
            }
        }, delay, unit);
        return future;
    }
}