hibernate cann't connect google could sql

Question

I'm working on smartgwt pro with a hibernate datasource. In development there is no no problem. When I deploy the app to Google there is a problem with the hibernate connection to Google Cloud SQL.

Here is my hibernate config:

<session-factory>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.GoogleDriver</property>
        <property name="connection.url">jdbc:google:mysql://jpacexpress:jpacdbinstance/jpac?user=root</property>

        <!-- 
        <property name="connection.driver_class">com.mysql.jdbc.GoogleDriver</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.driver_class">com.google.appengine.api.rdbms.AppEngineDriver</property>

        <property name="connection.url">jdbc:mysql://localhost:3306/jpac</property>
        <property name="connection.url">jdbc:google:rdbms://jpacexpress:jpacdbinstance/jpac</property>
        <property name="connection.url">jdbc:google:mysql://jpacexpress:jpacdbinstance/jpac</property>
        -->

        <property name="connection.username">root</property>
        <property name="connection.password">xxxx</property>

        <property name="connection.pool_size">0</property>

I'm have tried changing the connection driver class and URL (see comments) . It also doesn't work.

Does anyone have a suggestion?