因为我不是专门研究多线程的，所以问题可能很低级，甚至很愚蠢，请原谅=）
这里是我的代码调用流程；
messagenotificationjobexecutionconfig->asyncmessagenotificationjobexecutor->notificationjobexecutor.execute（）
messagenotificationjobexecutionconfig（查找要处理的对象）并在循环内调用asyncmessagenotificationjobexecutor
asyncmessagenotificationjobexecutor在execute（）方法上有@async（“messagenotificationtaskexecutor”）注解。
asyncmessagenotificationjobexecutor.execute（）方法调用notificationjobexecutor.execute（）
messagenotificationtaskexecutor是threadpooltaskexecutor的示例
这是我的问题；
如果我没有错作为默认notificationjobexecutor有一个单音示例。
即使asyncmessagenotificationjobexecutor异步工作并使用线程池任务执行器，所有线程也只调用notificationjobexecutor示例（单音）。
我不确定，我可能误解了线程\u 1调用notificationjobexecutor.execute（），在该线程完成其作业之前，其他线程将等待线程\u 1。我的推论正确吗？
我认为即使它看起来是多线程的，实际上它也是单音的

@Component("messageNotificationTaskExecutor")
public class MessageNotificationThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {

    @Value("${message.notification.task.executor.corePoolSize}")
    Integer corePoolSize;

    @Value("${message.notification.task.executor.maxPoolSize}")
    Integer maxPoolSize;

    @Value("${message.notification.task.executor.queueCapacity}")
    Integer queueCapacity;

    public MessageNotificationThreadPoolTaskExecutor() {
        super();
    }

    @PostConstruct
    public void init() {
        super.setCorePoolSize(corePoolSize);
        super.setMaxPoolSize(maxPoolSize);
        super.setQueueCapacity(queueCapacity);
    }

}

@Configuration
public class MessageNotificationJobExecutionConfig {

    protected Logger log = LoggerFactory.getLogger(getClass());

    @Autowired
    AsyncMessageNotificationJobExecutor asyncMessageNotificationJobExecutor;

    @Autowired
    MessageNotificationThreadPoolTaskExecutor threadPoolTaskExecutor;

    @Autowired
    JobExecutionRouter jobExecutionRouter;

    @Autowired
    NotificationJobService notificationJobService;

    private Integer operationType = OperationType.ACCOUNT_NOTIFICATION.getValue();

    @Scheduled(cron = "${message.notification.scheduler.cronexpression}")
    public void executePendingJobs() {

        List<NotificationJob> nextNotificationJobList = notificationJobService.findNextJobForExecution(operationType, 10);

        for (NotificationJob nextNotificationJob : nextNotificationJobList) {
            if (threadPoolTaskExecutor.getActiveCount() < threadPoolTaskExecutor.getMaxPoolSize()) {
                asyncMessageNotificationJobExecutor.execute(nextNotificationJob);
            }
        }
    }
}

@Service
public class AsyncMessageNotificationJobExecutor {

    @Autowired
    NotificationJobExecutor notificationJobExecutor;

    @Autowired
    NotificationJobService notificationJobService;

    @Async("messageNotificationTaskExecutor")
    public void execute(NotificationJob notificationJob) {
            notificationJobExecutor.execute(notificationJob);
    }
}

@Component
public class NotificationJobExecutor implements JobExecutor {

    @Override
    public Integer getOperationType() {
        return OperationType.ACCOUNT_NOTIFICATION.getValue();
    }

    @Override
    public String getOperationTypeAsString() {
        return OperationType.ACCOUNT_NOTIFICATION.name();
    }

    @Override
    public void execute(NotificationJob notificationJob) {
        // TODO: 20.08.2020 will be execute 
    }

}