到新公司（有自己的一套框架）已经半年有余了，一直没有关注过java开源框架了。这几天突然感觉自己在技术上没有核心竞争力，于是决定狂补……
打算一个月内把hibernate全面的学习用一下（一直不知道hibernate search，跟lucene的完美结合，挺屌的）。这里我是直接从jboss官网上去看的hibernate documentation，下面我说一下这几天的所得，当然hibernate的基本架构和原理就不说了（官网上写的清清楚楚）。下面是我遇到的问题：
2014-3-11 13:17:15 org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>
INFO: HCANN000001: Hibernate Commons Annotations {4.0.4.Final}
2014-3-11 13:17:15 org.hibernate.Version logVersion
INFO: HHH000412: Hibernate Core {4.3.2.Final}
2014-3-11 13:17:15 org.hibernate.cfg.Environment <clinit>
INFO: HHH000206: hibernate.properties not found
2014-3-11 13:17:15 org.hibernate.cfg.Environment buildBytecodeProvider
INFO: HHH000021: Bytecode provider name : javassist
2014-3-11 13:17:15 org.hibernate.cfg.Configuration configure
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml
2014-3-11 13:17:15 org.hibernate.cfg.Configuration getConfigurationInputStream
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml
2014-3-11 13:17:16 org.hibernate.cfg.Configuration addResource
INFO: HHH000221: Reading mappings from resource: org/hibernate/tutorial/domain/Event.hbm.xml
2014-3-11 13:17:16 org.hibernate.cfg.Configuration doConfigure
INFO: HHH000041: Configured SessionFactory: null
2014-3-11 13:17:16 org.hibernate.engine.jdbc.connections.internal.ConnectionProviderInitiator initiateService
WARN: HHH000181: No appropriate connection provider encountered, assuming application will be supplying connections
Initial SessionFactory creation failed.org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
Exception in thread "main" java.lang.ExceptionInInitializerError
at org.hibernate.tutorial.util.HibernateUtil.buildSessionFactory(HibernateUtil.java:28)
at org.hibernate.tutorial.util.HibernateUtil.<clinit>(HibernateUtil.java:9)
at org.hibernate.tutorial.EventManager.createAndStoreEvent(EventManager.java:22)
at org.hibernate.tutorial.EventManager.main(EventManager.java:15)
Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:104)
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:71)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:209)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:89)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:206)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:178)
at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1885)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1843)
at org.hibernate.tutorial.util.HibernateUtil.buildSessionFactory(HibernateUtil.java:15)
... 3 more
如果你要是看我的blog，到这里估计你会觉得楼主很蛋疼。不过我可以坦白的说，这是直接在官网上copy的demo所出的issues。官网上的这个例子用的数据库是HSQLDB（我以后简称内存数据库，我也是第一次接触，搞得又跑到hsqldb官网下载，看了一下使用文档）。这几天我一直被这个问题困扰我对比了以前的版本，并且自己按以前版本写了也不会出问题，可是这次官网上的老让我郁闷了。下面是官网上对Sessionfactory的再次封装：
package org.hibernate.tutorial.util;
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() {
SessionFactory sessionFactory = null;
try {
// Create the SessionFactory from hibernate.cfg.xml
sessionFactory = 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);
}
return sessionFactory;
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
这样会报刚才提到的错误。
下面是我按以前版本，自己封装的：
package org.hibernate.tutorial.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
SessionFactory sessionFactory = null;
try {
// Create the SessionFactory from hibernate.cfg.xml
sessionFactory = new Configuration().configure().buildSessionFactory();
}
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);
}
return sessionFactory;
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
在hibernate4.3.X中buildSessionFactory()方法已经过时，但是能正常运行。
下面是用Hibernate4.3.x的api结合网上修改后的：
package org.hibernate.tutorial.util;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.boot.registry.internal.StandardServiceRegistryImpl;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
SessionFactory sessionFactory = null;
try {
// Create the SessionFactory from hibernate.cfg.xml
Configuration configuration = new Configuration().configure();
StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder()
.applySettings(configuration.getProperties());
StandardServiceRegistryImpl registry = (StandardServiceRegistryImpl) builder
.build();
sessionFactory = configuration.buildSessionFactory(registry);
}
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);
}
return sessionFactory;
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
}
这个能正常运行，这个跟官网的代码一对比就显而易见的发现官网上为什么会报错了。
这个不得不提一下Hibernate4.x推荐使用Service Register机制。
以后我会详细记录什么是Service Register机制的。