[Postgis][javax.sql.DataSource] Failed

Hi,

I'm developping an application on Tomcat7.

I'm using the DataSource for pooling my connection :

<Context reloadable="false">
<Resource name="jdbc/TestPool"
auth="Container"
type="javax.sql.DataSource"
maxActive="100"
maxIdle="30"
maxWait="20000"
logAbandoned="true"
removeAbandoned="true"
removeAbandonedTimeout="10"
testOnBorrow="true"
validationQuery="SELECT 1"
validationInterval="30000"
username="Test"
password="**********"
driverClassName="org.postgresql.Driver"
url="jdbc:postgresql://172.17.100.14/D_TEST?autoReconnect=true"
/>
</Context>

It seems that the connection that I got can't be casted to PGconnection :

java.lang.ClassCastException:
org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper
cannot be cast to org.postgresql.PGConnection
at Test.DataBaseConnector.connection(DataBaseConnector.java:134)
at Test.DataBaseConnector.<init>(DataBaseConnector.java:94)
at Test.Guardian_Process.<init>(Guardian_Process.java:36)
at Test.ServletListener.contextInitialized(ServletListener.java:36)
at
org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4600)
at
org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5097)
at
org.apache.catalina.core.StandardContext$1.call(StandardContext.java:5092)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown
Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

So my question is:

How can I manipulate geometry data In my case ?