Latest Oracle jdbc driver (11.2.0.1.0) explicit states that Oracle Implicit Connection cache (which is that one that use OracleDataSource) it’s deprecated :

Oracle JDBC Drivers release 11.2.0.1.0 production Readme.txt

What Is New In This Release ?

Universal Connection Pool
In this release the Oracle Implicit Connection Cache feature is
deprecated. Users are strongly encouraged to use the new Universal
Connection Pool instead. The UCP has all of the features of the
ICC, plus much more. The UCP is available in a separate jar file,
ucp.jar.

So I think it’s better to start using UCP, but the documentation it’s not that good.
For example I didn’t find a way to use UCP with spring…

UPDATE: I’ve found the correct spring configuration:
OK I think I’ve found the right configuration:

<bean id="dataSource" class="oracle.ucp.jdbc.PoolDataSourceFactory" factory-method="getPoolDataSource">
    <property name="URL" value="jdbc:oracle:thin:@myserver:1521:mysid" />
    <property name="user" value="myuser" />
    <property name="password" value="mypassword" />
    <property name="connectionFactoryClassName" value="oracle.jdbc.pool.OracleDataSource" />
    <property name="connectionPoolName" value="ANAG_POOL" />
    <property name="minPoolSize" value="5" />
    <property name="maxPoolSize" value="10" />
    <property name="initialPoolSize" value="5" />
    <property name="inactiveConnectionTimeout" value="120" />
    <property name="validateConnectionOnBorrow" value="true" />
    <property name="maxStatements" value="10" />
</bean>

The key is to specify the right factory class and the right factory method