hibernate5 创建SessionFactory 总结三种方法均可（亲测）

第一种：与hibernate4.0之前相同，只需要一句

SessionFactory factory = cfg.buildSessionFactory();

第二种：稍微麻烦

StandardServiceRegistry standardServiceRegistry = new StandardServiceRegistryBuilder().configure().build();
       Metadata metadata = new MetadataSources(standardServiceRegistry).getMetadataBuilder()
               .applyImplicitNamingStrategy(ImplicitNamingStrategyComponentPathImpl.INSTANCE).build();
       SessionFactory factory = metadata.getSessionFactoryBuilder().build();

第三种：这种在官网下载的hibernate5中有 user-guide文档说明，所以跟着官方写应该不会出错

此为文档目录：\hibernate-release-5.4.4.Final\documentation\userguide\html_single\Hibernate_User_Guide.html

protected void setUp() throws Exception {
	// A SessionFactory is set up once for an application!
	final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
			.configure() // configures settings from hibernate.cfg.xml
			.build();
	try {
		sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
	}
	catch (Exception e) {
		// The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
		// so destroy it manually.
		StandardServiceRegistryBuilder.destroy( registry );
	}
}

以下为上方的精简版：

ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
        SessionFactory factory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory();

最后创建session：Session session = factory.openSession();

三种方法均可实现创建SessionFactory.