Spring + Hibernate 的多租户：“SessionFactory 配置为多租户，但未指定租户标识符”

使用Spring和Hibernate进行多租户的配置是一种常见的需求。在某些情况下，我们想要将一个应用程序扩展给多个租户，每个租户有独立的数据库或数据表。在本文中，我们将介绍如何配置SessionFactory为多租户，但未指定租户标识符的情况。

java
@Configuration
@EnableTransactionManagement
public class HibernateConfig {
    @Autowired
    private DataSource dataSource;
    @Bean
    public LocalSessionFactoryBean sessionFactory() {
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setPackagesToScan("com.example.model");
        sessionFactory.setHibernateProperties(hibernateProperties());
        return sessionFactory;
    }
    @Bean
    public HibernateTransactionManager transactionManager(SessionFactory sessionFactory) {
        HibernateTransactionManager transactionManager = new HibernateTransactionManager();
        transactionManager.setSessionFactory(sessionFactory);
        return transactionManager;
    }
    private Properties hibernateProperties() {
        Properties properties = new Properties();
        properties.put("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        properties.put("hibernate.show_sql", "true");
        properties.put("hibernate.format_sql", "true");
        return properties;
    }
}

java
@Service
public class ProductService {
    @Autowired
    private SessionFactory sessionFactory;
    public List getProducts() {
        // 获取当前租户标识符
        String tenantIdentifier = TenantContext.getTenantIdentifier();
        // 设置当前租户
        sessionFactory.getCurrentSession().enableFilter("tenantFilter").setParameter("tenantIdentifier", tenantIdentifier);
        // 执行查询
        Session session = sessionFactory.getCurrentSession();
        Query query = session.createQuery("FROM Product");
        List products = query.list();
        return products;
    }
}