今天升级hibernate3.2GA遇到一个很奇怪的问题(谢谢大家，已解决) HibernateMySQLCacheSpringOpenSource

今天看到hibernate3.2ga版出来，赶紧更新。

我原来用的是hibernate3.1.3版本+Spring2.0，结果更新后，我配置的c3p0连接池是死活也连接不上了。

数据库是mysql，它在那里一直"Building new Hibernate SessionFactory".

一口气创建了好多。输出信息是这样的：

....－Building new Hibernate SessionFactory
....－Building new Hibernate SessionFactory
....－Building new Hibernate SessionFactory
....－Building new Hibernate SessionFactory
....－Building new Hibernate SessionFactory

然后报错：

WARN  com.mchange.v2.resourcepool.BasicResourcePool - com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@16528a2 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30).
2006-10-18 02:07:03,125 [main] WARN  org.hibernate.cfg.SettingsFactory - Could not obtain connection metadata
java.sql.SQLException: Connections could not be acquired from the underlying database!


把jar包换成hibernate3.1.3.jar就完全正常，用hibernate3.2GA的包就出上面的错误。


我的配置如下：

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="mappingResources">
<list>
<value>/domain/Admin.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<!--connection-->
<prop key="hibernate.connection.driver_class">${hibernate.connection.driver_class}</prop>
<prop key="hibernate.connection.url">${hibernate.connection.url}</prop>
<prop key="hibernate.connection.username">${hibernate.connection.username}</prop>
<prop key="hibernate.connection.password">${hibernate.connection.password}</prop>
<prop key="hibernate.useUnicode">${hibernate.useUnicode}</prop>
<prop key="hibernate.characterEncoding">${hibernate.characterEncoding}</prop>
<prop key="hibernate.autoReconnect">${hibernate.autoReconnect}</prop>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.default-lazy-init">${hibernate.default-lazy-init}</prop>
<prop key="hibernate.connection.provider_class">${hibernate.connection.provider_class}</prop>
<!--Connection Pooling-->
<prop key="hibernate.c3p0.max_size">${hibernate.c3p0.max_size}</prop>
<prop key="hibernate.c3p0.min_size">${hibernate.c3p0.min_size}</prop>
<prop key="hibernate.c3p0.timeout">${hibernate.c3p0.timeout}</prop>
<prop key="hibernate.c3p0.max_statements">${hibernate.c3p0.max_statements}</prop>
<prop key="hibernate.c3p0.idle_test_period">${hibernate.c3p0.idle_test_period}</prop>
<prop key="hibernate.c3p0.acquire_increment">${hibernate.c3p0.acquire_increment}</prop>
<prop key="hibernate.c3p0.validate">${hibernate.c3p0.validate}</prop>
</props>
</property>
</bean>



实在是不明白这两个版本的hibernate为什么会造成这种情况，不知道大家有没有出现过这种情况，怎么解决这个问题呢？？？




问题已解决，谢谢大家！

产生的问题是因为没有配置hibernate.cache.provider_class，很奇怪的问题，在3.1.3版本中缓存提供类并非必须的。而在3.2版本中，则必须配置才可以正常创建连接池。

：） 万分感谢楼下各位的热心！！