The user must supply a JDBC connection这个是什么原因啊。？

<property name="hibernateProperties">   
             <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>   
                <prop key="hibernate.proxool.pool_alias">datasource</prop>  
                <prop key="hibernate.proxool.xml">/WEB-INF/proxool.xml</prop><!--指定Proxool配置文件--> 
                <prop key="hibernate.proxool.existing_pool">true</prop> 
                <prop key="hibernate.connection.release_mode">auto</prop>
                <prop key="connection.provider_class">org.hibernate.connection.ProxoolConnectionProvider</prop>
                <prop key="hibernate.connection.autocommit">true</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>   
        </property>