java Hibernate 4.3，在构建SessionFactory时，为什么必须提供两次属性？

Question

使用Hibernate 4.3.5创建SessionFactory（例如单元测试）时，必须提供两次属性：

1. 一次用于配置
2. 第二次，将设置应用于service registry builder时

示例如下所示：

Properties properties = new Properties();
properties.put("hibernate.dialect", "org.hibernate.dialect.HSQLDialect");
properties.put("hibernate.connection.driver_class", "org.hsqldb.jdbcDriver");
properties.put("hibernate.connection.url", "jdbc:hsqldb:mem:test");
properties.put("hibernate.connection.username", "sa");
properties.put("hibernate.connection.password", "");
properties.put("hibernate.hbm2ddl.auto", "update");
properties.put("hibernate.show_sql", "true");

SessionFactory sessionFactory = new Configuration()
    .addProperties(properties)
    .addAnnotatedClass(SecurityId.class)
    .buildSessionFactory(
            new StandardServiceRegistryBuilder()
                    .applySettings(properties)
                    .build()
);  

如果我评论：

//.addProperties(properties)

那么“hibernate.hbm2ddl.auto”属性就不完整了：

Caused by: org.hsqldb.HsqlException: user lacks privilege or object not found: SECURITYID

如果我评论：

//.applySettings(properties)

我得到：

org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set 

尾码可在GitHub上找到

Answer 1

尝试以下代码，它使用配置中的属性

Configuration configuration = new Configuration();
configuration.addAnnotatedClass(SecurityId.class);
configuration.addProperties(properties);
configuration.configure();
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);