即使没有可用的 SessionFactory 实例，Spring @Autowired 如何绑定 SessionFactory 对象

Question

我将 Hibernate 和 Spring 与基于 Java 的配置一起使用。我的配置文件是这个：

@Bean
@Autowired
public HibernateTransactionManager transactionManager(SessionFactory s) {
   HibernateTransactionManager txManager = new HibernateTransactionManager();
   txManager.setSessionFactory(s);
   return txManager;
}

@Bean
public LocalSessionFactoryBean sessionFactory() {
    LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
    sessionFactory.setDataSource(dataSource());
    sessionFactory.setPackagesToScan(new String[] { "dto" });
    sessionFactory.setHibernateProperties(hibernateProperties());
    return sessionFactory;
 }

工作正常。这个没问题，但是当我手动尝试为trasactionManager设置sessionfactory参数时，像这样：

@Bean
@Autowired
public HibernateTransactionManager transactionManager(SessionFactory s) {
   HibernateTransactionManager txManager = new HibernateTransactionManager();
   txManager.setSessionFactory(sessionFactory());
   return txManager;
}

IDE 正在显示：

`The method setSessionFactory(SessionFactory) in the type HibernateTransactionManager is not applicable for the arguments (LocalSessionFactoryBean)`

所以，我创建了一个如下所示的 sessionFactory

@Bean
@Autowired
public SessionFactory sessionFactory(DataSource dataSource) {
    LocalSessionFactoryBuilder sessionFactory = new LocalSessionFactoryBuilder(dataSource);
    sessionFactory.addProperties(hibernateProperties());
    sessionFactory.scanPackages("dto");
    return sessionFactory.buildSessionFactory();

}

并传递给trasactionManager 成功了。

我的问题是，即使第一种方法中不存在 sessionFactory 实例，spring 如何自动装配 sessionFactory 对象？

Answer 1

您需要将方法返回类型从SessionFactory 更改为HibernateTransactionManager。

它应该是这样的：

@Bean
@Autowired
public HibernateTransactionManager transactionManager(SessionFactory s) {
   HibernateTransactionManager txManager = new HibernateTransactionManager();
   txManager.setSessionFactory(s);
   return txManager;
}

@Bean
public SessionFactory sessionFactory() {
    Properties properties = new Properties();
    properties.setProperty("hibernate.show_sql", "true")
    properties.setProperty("hibernate.cache.region.factory_class", "org.hibernate.cache.ehcache.EhCacheRegionFactory")
    properties.setProperty("hibernate.cache.use_query_cache", "true")
    properties.setProperty("hibernate.cache.use_second_level_cache", "true")
    properties.setProperty("hibernate.dialect", "org.hibernate.dialect.HSQLDialect")

    return new LocalSessionFactoryBuilder(dataSource())
        .scanPackages("dto")
        .addProperties(properties)
        .buildSessionFactory();
}