Spring boot @Async 注解抛出 LazyInitialization

Question

我有一个 emailsenderservice 来异步管理电子邮件通知。有 2 种异步方法，一种方法有效，但另一种方法抛出 LazyInitializationException：

@Service

public class EmailSenderService {

    // working

    @Async

    public void sendNewBidRequestEmail(BidRequest bidRequest) {

        this.sendNewBidRequestEmailToSupplier(bidRequest);

    }

    @Transactional

    public void sendNewBidRequestEmailToSupplier(BidRequest bidRequest) {

        sendNewBidRequestEmailToSupplier(bidRequest, bidRequest.getHotels());

    }

    @Transactional

    public void sendNewBidRequestEmailToSupplier(BidRequest bidRequest, List<Hotel> hotelList) {

        for (Hotel hotel : hotelList) {

           ...

           this.sender.send()

        }

    }

    // not working, throw exception

    @Async

    public void sendCancelledBidRequestEmail(BidRequest bidRequest, String reason) {

        this.sendCancelledBidRequestEmailToSupplier(bidRequest, bidRequest.getHotels(), reason);

    }

    @Transactional

    public void sendCancelledBidRequestEmailToSupplier(BidRequest bidRequest, List<Hotel> hotelList, String reason) {

        for (Hotel hotel : hotelList) {   // throw exception here

           ...

           this.sender.send();

        }

}

我完全按照这个线程。您可以看到两种异步方法具有几乎相同的结构。异步方法调用事务方法。而第二个抛出org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: com.corpobids.server.entity.BidRequest.hotels, could not initialize proxy - no Session。