Connection cannot be null when 'hibernate.dialect' not set问题的解决

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本人刚开始学hibernate的小白，今天遇到了这样的问题，下面贴出解决方法，希望对其他遇到同样问题的初学者有帮助

import org.hibernate.HibernateException;

import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.service.ServiceRegistryBuilder;public class HibernateUtil {private static final ThreadLocal<Session> threadLocal=new ThreadLocal<Session>();private static SessionFactory sessionFactory=null;static {try{/*Configuration cfg = new Configuration().configure("hibernate.cfg.xml");sessionFactory = cfg.buildSessionFactory();*/Configuration cfg = new Configuration();ServiceRegistry serviceRegistry =new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();sessionFactory = cfg.buildSessionFactory(serviceRegistry);}catch(HibernateException e){System.out.println("创建会话工厂失败");e.printStackTrace();}}public static Session getsession() throws HibernateException{Session session=(Session)threadLocal.get();if(session==null||!session.isOpen()){if(sessionFactory==null){rebuildsessionFactory();}session=(sessionFactory!=null)?sessionFactory.openSession():null;threadLocal.set(session);}return session;}public static void rebuildsessionFactory(){try{/*Configuration cfg = new Configuration().configure();sessionFactory = cfg.buildSessionFactory();*/Configuration cfg = new Configuration().configure();ServiceRegistry serviceRegistry =new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();sessionFactory = cfg.buildSessionFactory(serviceRegistry);}catch(Exception e){System.out.println("创建会话工厂失败");e.printStackTrace();}}public static SessionFactory getsessionFactory(){return sessionFactory;}public static void closesession() throws HibernateException{Session session=(Session)threadLocal.get();threadLocal.set(null);if(session!=null){session.close();}}public static void main(String[] args) {        System.out.println(getsessionFactory());    }}

先贴上我的代码，

运行后控制台输出如下：

十一月 15, 2016 5:27:18 下午 org.hibernate.annotations.common.Version <clinit>INFO: HCANN000001: Hibernate Commons Annotations {4.0.2.Final}十一月 15, 2016 5:27:19 下午 org.hibernate.Version logVersionINFO: HHH000412: Hibernate Core {4.2.4.Final}十一月 15, 2016 5:27:19 下午 org.hibernate.cfg.Environment <clinit>INFO: HHH000206: hibernate.properties not found十一月 15, 2016 5:27:19 下午 org.hibernate.cfg.Environment buildBytecodeProviderINFO: HHH000021: Bytecode provider name : javassist十一月 15, 2016 5:27:19 下午 org.hibernate.service.jdbc.connections.internal.ConnectionProviderInitiator initiateServiceWARN: HHH000181: No appropriate connection provider encountered, assuming application will be supplying connections创建会话工厂失败org.hibernate.HibernateException: Connection cannot be null when 'hibernate.dialect' not setat org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:97)at org.hibernate.service.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:67)at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:174)at org.hibernate.service.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:75)at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:159)at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:131)at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1818)at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1776)at hibernate.HibernateUtil.<clinit>(HibernateUtil.java:19)null

这是因为下面这行代码后面缺少.configure()，没有导入配置文件导致的

Configuration cfg = new Configuration();

这行代码改为：

Configuration cfg = new Configuration().configure();

根据错误提示Connection cannot be null when 'hibernate.dialect' not set猜想，可能只要是没找到hibernate.dialect都会输出同样的错误，会有其他的问题导致同样的错误

。有遇到人的可以在下面补充下。

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