hibernate4+proxool问题

[yushihai]

hibernate新手，项目使用JDBC连接时一切正常，但使用Proxool连接池时就会出现错误。错误提示是:java.sql.SQLException: The url cannot be null
proxool.xml代码如下:

<?xml version="1.0" encoding="utf-8"?>
<!-- the proxool configuration can be embedded within your own application's.
Anything outside the "proxool" tag is ignored. -->
<something-else-entirely>
    <proxool>
        <alias>DBPool</alias>
        <driver-url>jdbc:mysql://localhost:3306/djb?characterEncoding=utf-8</driver-url>
        <driver-class>com.mysql.jdbc.Driver</driver-class>
        <driver-properties>
            <property name="user" value="root"/>
            <property name="password" value="root"/>
        </driver-properties>
        <house-keeping-sleep-time>90000</house-keeping-sleep-time>
        <maximum-new-connections>20</maximum-new-connections>
        <prototype-count>5</prototype-count>
        <maximum-connection-count>100</maximum-connection-count>
        <minimum-connection-count>10</minimum-connection-count>
        <house-keeping-test-sql>
            select CURRENT_DATE
        </house-keeping-test-sql>
    </proxool>
</something-else-entirely>

hibernate.cfg.xml相关配置如下:

	<!-- 配置proxool数据源 -->
		<property name="hibernate.connection.provider_class">
		<!-- org.hibernate.connection.ProxoolConnectionProvider -->
		org.hibernate.service.jdbc.connections.internal.ProxoolConnectionProvider
		</property>
		<property name="proxool.pool_alias">DBPool</property>
	 <property name="proxool.xml">WEB-INF/Proxool.xml</property>
		<!--<property name="proxool.properties">Proxool.properties</property>-->
		<property name="proxool.existing_pool">true</property> 
	<!-- 是否在控制台打印SQL -->
	<property name="show_sql">true</property>
	<!-- 格式化SQL -->
	<property name="format_sql">true</property>
	<!-- 指定自动生成数据表策略 -->
	<property name="hibernate.hbm2ddl.auto">update</property>