Spring Boot - @Transactional 标注的方法如何使用 synchronized？

这篇文章中有说到 @Transactional 标注的方法也有锁的情况下会出现一些问题，具体请看 Spring Boot 锁。

而且 Idea 也会标一个黄色波浪线提示你。我是这样做的，仅供参考。

file:[DiscussionService.java]
@Service
public class DiscussionService implements IDiscussionService {
    private final DiscussionMapper discussionMapper;
    private final TransactionalWrapper transactionalWrapper;

    public DiscussionService(DiscussionMapper discussionMapper) {
        this.discussionMapper = discussionMapper;
        transactionalWrapper = new TransactionalWrapper(discussionMapper);
    }

    @Override
    public synchronized int upgradeArticle(ArticleModel model, DiscussionCriteria criteria) {
        return transactionalWrapper.doUpgradeArticle(model, criteria);
    }
}

@AllArgsConstructor
class TransactionalWrapper {

    private DiscussionMapper discussionMapper;

    @Transactional
    public int doUpgradeArticle(ArticleModel model, DiscussionCriteria criteria) {
        try {
            // ...
            Integer affectRows = discussionMapper.upgradeArticle(model);
            return affectRows > 0 ? 1 : 0;
        } catch (Exception e) {
            throw new JdbcErrorException(e);
        }
    }

}