java – HibernateException：无法获取当前线程的事务同步会话

Exception in thread "main" org.hibernate.HibernateException: 
Could not obtain transaction-synchronized Session for current thread

主要

ppService.deleteProductPart(cPartId, productId);

@Service( “productPartService”)

@Override
public void deleteProductPart(int cPartId, int productId) {
    productPartDao.deleteProductPart(cPartId, productId);
}

@Repository( “productPartDAO”)

@Override
    public void deleteProductPart(ProductPart productPart) {
        sessionFactory.getCurrentSession().delete(productPart);
    }


@Override
    public void deleteProductPart(int cPartId, int productId) {
        ProductPart productPart  = (ProductPart) sessionFactory.getCurrentSession()
                .createCriteria("ProductPart")
                .add(Restrictions.eq("part", cPartId))
                .add(Restrictions.eq("product", productId)).uniqueResult();
        deleteProductPart(productPart);
    }

怎么解决？

更新：

如果我修改这样的方法：

@Override
@Transactional
public void deleteProductPart(int cPartId, int productId) {          
    System.out.println(sessionFactory.getCurrentSession());
}

它返回：

SessionImpl(PersistenceContext[entityKeys=[],collectionKeys=[]];ActionQueue[insertions=[] updates=[] deletions=[] collectionCreations=[] collectionRemovals=[] collectionUpdates=[] collectionQueuedOps=[] unresolvedInsertDependencies=UnresolvedEntityInsertActions[]])

但是如果我删除@Transactional它会以异常结束：

org.hibernate.HibernateException: Could not obtain transaction-synchronized Session for current thread

我通过添加@Transactional来实现它,但现在我得到了org.hibernate.MappingException：未知实体：ProductPart虽然我将.uniqueResult()链接到Criteria.怎么解决？

createCriteria(ProductPart.class)

从API开始,使用String和Class的区别如下：

Session.createCriteria(String)

Create a new Criteria instance, for the given entity name. 

Session.createCriteria(Class)

Create a new Criteria instance, for the given entity class, or a
superclass of an entity class, with the given alias.

如果传递String,则hibernate会查找名称为ProductPart的实体.