Hibernate4.3.5之"hibernate.dialect" not set问题

在利用Hibernate（4.3.5）用户手册中提供的HibernateUtil帮助类产生的SessionFactory实例进行数据库访问时，会产生

Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set异常(配置文件用的是hibernate.cfg.xml）

以下是Hibernate用户手册中的HibernateUtil帮助类（而且它的buildSessionFactory（）方法中还缺少了return 语句）

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {

private static final SessionFactory sessionFactory = buildSessionFactory();

private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
new Configuration().configure().buildSessionFactory(
new StandardServiceRegistryBuilder().build() );
}
catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory() {
return sessionFactory;
}

}

根据网上针对"hibernate.dialect" not set问题的解决方法，可将该帮助类稍作修改，如下：

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class HibernateUtil
{
private static final SessionFactory sessionFactory = buildSessionFactory();

private static SessionFactory buildSessionFactory() {
try {
Configuration configuration = new Configuration().configure();
ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
return configuration.buildSessionFactory(serviceRegistry);
}
catch (Throwable ex) {
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}

public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}

如上修改后，当你cfg文件正确配置的前提下，再利用该类获取的SessionFactory进行相关操作时应该不会再报上述异常了（在H4.3.5版上做过简单测试）