Hibernate数据库会话处理

Question

我有一个使用[ { "$ref": "ObjectName", "$id": { "$oid": "4f835168e4b041cb4cf48119" } }, { "$ref": "ObjectName", "$id": { "$oid": "4f834cade4b041cb4cf48108" } }, .... more element in the array ... ] 来处理数据库连接的应用程序。例如：

sessionFactory

但如果我运行此查询

public List<APN> getList() throws org.hibernate.HibernateException {        
        List<APN> result = (List<APN>) sessionFactory.getCurrentSession()
                .createQuery("from APN").list();
        return result;
}

不会给出任何行。这是否意味着，hibernate每次都会重新创建会话？这可以吗？这是否意味着hibernate为每个查询创建新的jdbc连接？我知道这是一个有点沉重的程序。

hibernate.cfg.xml中：

select * from v$session where username='MY_USER'

root-context：

<hibernate-configuration>
    <session-factory>
    <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> 
    <property name="hibernate.c3p0.min_size">5</property>
        <property name="hibernate.c3p0.max_size">20</property>
        <property name="hibernate.c3p0.timeout">300</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.idle_test_period">3000</property>
        <mapping class="ru.tenet.pcrf.domain.RedirectionServer" />      
        <mapping class="ru.tenet.pcrf.domain.DeviceType" />
        <mapping class="ru.tenet.pcrf.domain.FlowTemplate" />       
        <mapping class="ru.tenet.pcrf.domain.QoS" />    
        <mapping class="ru.tenet.pcrf.domain.MonitoringKey" />  
        <mapping class="ru.tenet.pcrf.domain.Rule" />   
        <mapping class="ru.tenet.pcrf.domain.RuleFlows" />
        <mapping class="ru.tenet.pcrf.domain.Policy" />
        <mapping class="ru.tenet.pcrf.domain.PolicyContent" />
        <mapping class="ru.tenet.pcrf.domain.APN" />
        <mapping class="ru.tenet.pcrf.domain.Location" />
        <mapping class="ru.tenet.pcrf.domain.QuotaTemplate" />
        <mapping class="ru.tenet.pcrf.domain.SGSNNode" />
        <mapping class="ru.tenet.pcrf.domain.RuleSCE" />
        <mapping class="ru.tenet.pcrf.domain.Protocol" />
        <mapping class="ru.tenet.pcrf.domain.Peer" />
        <mapping class="ru.tenet.pcrf.domain.User" />
        <mapping class="ru.tenet.pcrf.domain.Role" />
        <mapping class="ru.tenet.pcrf.domain.SessionList" />
        <mapping class="ru.tenet.pcrf.domain.SessionRule" />
        <mapping class="ru.tenet.pcrf.domain.SessionLocation" />
        <mapping class="ru.tenet.pcrf.domain.SubscriptionData" />
        <mapping class="ru.tenet.pcrf.domain.Subscriber" />
        <mapping class="ru.tenet.pcrf.domain.SubscriberPolicy" />       
        <mapping class="ru.tenet.pcrf.domain.SubscriberQuota" />
        <mapping class="ru.tenet.pcrf.domain.Device" />
        <mapping class="ru.tenet.pcrf.domain.RequestCounter" />
        <mapping class="ru.tenet.pcrf.domain.SessionCounter" />

    </session-factory>
</hibernate-configuration>