private void test() {
        CompletableFuture.supplyAsync(new Supplier<String>() {
            @Override
            public String get() {
                System.out.println("开始休眠...");
                try {
                    Thread.sleep(3000);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                System.out.println("休眠结束");

                return "线程结果";
            }
        }).whenComplete(new BiConsumer<String, Throwable>() {
            @Override
            public void accept(String s, Throwable throwable) {
                System.out.println("accept:" + s);
            }
        });
    }