试图使用HibernateTransactionManager，但是事务服务抛出HibernateException

Question

I'm trying to convert a Spring 4 project to use HibernateTransactionManager to manage the transactions, but transactional services throw this exception:

org.hibernate.HibernateException: createSQLQuery is not valid without active transaction

I've searched on google, and 80 different people have 80 different ways of doing it. I've tried them all, and either they don't work or they require using EntityManager instead of Hibernate Sessions. Since I'm converting existing code that uses Hibernate sessions, things would be far easier if I could get them to work. How do I get rid of this exception?

• Spring version: 4.2.5.RELEASE
• Hibernate version: 5.1.0.Final
• Hikari version: 2.7.6
• JDK version: 1.8.0_161

DataSource config:

@Configuration
public class DataSourceConfig {
    @Bean
    public DataSource dataSource() {
        // return a Hikari connection pool as the data source
        try {
            HikariDataSource bean = new HikariDataSource();
            // set connection pool and JDBC properties
            return bean;
        } catch (Exception e) {
            throw new RuntimeException("could create data source", e);
        }
    }
}

Session factory config:

@Configuration
public class SessionFactoryConfig {
    @Autowired
    private DataSource dataSource;

    @Bean
    public LocalSessionFactoryBean sessionFactory() {
        // create a session factory
        try {
            LocalSessionFactoryBean bean = new LocalSessionFactoryBean();
            // set Hibernate properties
            bean.setDataSource(dataSource);
            bean.setPackagesToScan(packagesToScan);
            bean.setHibernateProperties(properties);
            bean.afterPropertiesSet(); // tried without this line as well
            return bean;
        } catch (Exception e) {
            throw new RuntimeException("could not create session factory", e);
        }
    }
}

Transaction config:

@Configuration
@EnableTransactionManagement
@ComponentScan("com.mydomain.*")
public class TransactionConfig {
    @Autowired
    private SessionFactory sessionFactory;

    @Bean
    public PlatformTransactionManager transactionManager() {
        HibernateTransactionManager bean = new HibernateTransactionManager(sessionFactory);
//      bean.setHibernateManagedSession(true); // similar exception when set
        bean.afterPropertiesSet(); // tried without this line as well
        return bean;
    }
}

Service:

@Service
@Transactional // tried using only the @Transactional on the method
public class TestTransactionService {
    @Autowired
    private SessionFactory sessionFactory;

    @Transactional // tried using only the @Transactional on the class
    public String get(String key) {
        Session session = sessionFactory.getCurrentSession();
        // the below line throws the exception!
        SQLQuery q = session.createSQLQuery("SELECT value FROM test_transaction WHERE key = :key");
        q.setParameter("key", key);
        q.addScalar("value", StringType.INSTANCE);
        String out = (String)q.uniqueResult();
        return out;
    }
}

Any ideas? I hope so because I'm out.

Answer 1

Buried in our settings was this innocent-looking one, in there since the initial git checkin of our project, so I cannot find out who put it in (they're lucky):

hibernate.current_session_context_class = thread

Since no one knew what this setting was for, no one dared touch it since then. This breaks Spring managed transactions, and had no business being in there.

Let's this be a lesson, boys and girls: if you're trying to get something to work, DON'T just fiddle with settings when you don't know what they are. It will come back to bite you in the ass--sometimes years later. And then I will come find you and get you.