Spring boot@Async注释引发LazyInitializationException

Question

@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();
        }
}

我完全遵循这条线索。您可以看到这两种异步方法具有几乎相同的结构。异步方法调用事务性方法。但是第二个抛出org.hibernate.lazyInitializationException：未能懒洋洋地初始化角色集合:com.corpobids.server.entity.BidRequest.Hotels，无法初始化代理-没有会话。

我甚至模仿第一个异步方法结构来修改第二个：

@Async
    public void sendCancelledBidRequestEmail(BidRequest bidRequest, String reason) {
        this.sendCancelledBidRequestEmailToSupplier(bidRequest, reason);
    }

    @Transactional
    public void sendCancelledBidRequestEmailToSupplier(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) {   // exception in this line
               ...
               this.sender.send();
            }
    }
}

这一次，它给出了java.lang.IllegalStateException:org.hibernate.resource.jdbc.internal.logicalConnectionManagedimpl@fce9b7b is closed。

我想知道我的代码中的缺失点，任何帮助都将不胜感激。

Answer 1

您在JPA方面有问题。

在JPA中，关系OneToMany有两种行为：懒惰和渴望。

您可以查看一个很好的解释：Java持久化API中FetchType LAZY和EAGER之间的区别？

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