如何才能监听到收到消息的事件 about mirai-demos HOT 7 CLOSED

public static class CustomEventListener extends SimpleListenerHost {
        @EventHandler
        public ListeningStatus onFriendMsg(FriendMessageEvent event) {
            MessageReceipt<Contact> receipt = event.getSender().sendMessage("测试测试");
            receipt.recallIn(10000);
            return ListeningStatus.LISTENING;
        }

        @Override
        public void handleException(@NotNull CoroutineContext context, @javax.validation.constraints.NotNull Throwable exception) {
            super.handleException(context, exception);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        final Bot bot = BotFactoryJvm.newBot(qq, password, new BotConfiguration() {
            {
                fileBasedDeviceInfo("deviceInfo.json");
            }
        });
        bot.login();
        Events.registerEvents(bot, new CustomEventListener());
        bot.join();
    }