Datasource test connection fails in jboss eap 6.4

Question

I am trying to use jboss eap 6.4 with ibm sdk 1.8. I am trying to create a datasource which is a DB2 connection. However, when i try to do a test connection, it fails with the message -

Internal Server Error
{
    "outcome" => "failed",
    "failure-description" => "JBAS010440: failed to invoke operation: JBAS010447: Connection is not valid",
    "rolled-back" => true
}

The same works absolutely fine with ibm sdk 1.7. I have read online that jboss 6.4 does support 1.8 java version. Wondering what the issue is.. attaching my standalone.xml code which has the datasource configuration mentioned -

<datasource jta="false" jndi-name="java:jboss/datasources/APPDS" pool-name="APPDS" enabled="true" use-ccm="false">
                    <connection-url>jdbc:db2://<ip>:<port>/APPDEV:currentSchema=DB2INS;sslConnection=true;</connection-url>
                    <driver-class>com.ibm.db2.jcc.DB2Driver</driver-class>
                    <driver>db2jcc4.jar</driver>
                    <security>
                        <user-name>appdev</user-name>
                        <password>password</password>
                    </security>
                    <validation>
                        <valid-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.db2.DB2ValidConnectionChecker"/>
                        <check-valid-connection-sql>select current timestamp from sysibm.sysdummy1</check-valid-connection-sql>
                        <stale-connection-checker class-name="org.jboss.jca.adapters.jdbc.extensions.db2.DB2StaleConnectionChecker"/>
                        <exception-sorter class-name="org.jboss.jca.adapters.jdbc.extensions.db2.DB2ExceptionSorter"/>
                    </validation>
                    <statement>
                        <share-prepared-statements>false</share-prepared-statements>
                    </statement>
                </datasource>