Why do I get a "Unexpected error in pingDatabase java.lang.IllegalArgumentException: object is not an instance of declaring class" ?

Issue

• While trying to configure our datasource (Oracle connection pool) to validate connections, It throws "IllegalArgumentException"

• The DataSource is configured as below:

            <jndi-name>eDataDS</jndi-name>
            <connection-url>jdbc:oracle:thin:@server:1521:database</connection-url>
            <driver-class>oracle.jdbc.driver.OracleDriver</driver-class>
            <user-name>userid</user-name>
            <password>XXXXXXXXX</password>
            <min-pool-size>5</min-pool-size>
            <max-pool-size>20</max-pool-size>
            <!-- Uses the pingDatabase method to check a connection is
            still valid before handing it out from the pool
            -->
            <valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker</valid-connection-checker-class-name>
            <!-- Checks the Oracle error codes and messages for fatal errors -->
            <exception-sorter-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleExceptionSorter</exception-sorter-class-name>
            <!-- sql to call when connection is created . -->
            <new-connection-sql>select 1 from dual</new-connection-sql>
            <!-- sql to call on an existing pooled connection
                 when it is obtained from pool - the OracleValidConnectionChecker is prefered -->
            <check-valid-connection-sql>select 1 from dual</check-valid-connection-sql>
            <metadata>
             <type-mapping>Oracle9i</type-mapping>
            </metadata>
        </local-tx-datasource>

• But the following error is observed in the logs:

WARN  [org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker] (main) Unexpected error in pingDatabase
java.lang.IllegalArgumentException: object is not an instance of declaring class
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker.isValidConnection(OracleValidConnectionChecker.java:70)
        at org.jboss.resource.adapter.jdbc.BaseWrapperManagedConnectionFactory.isValidConnection(BaseWrapperManagedConnectionFactory.java:570)
        at org.jboss.resource.adapter.jdbc.BaseWrapperManagedConnection.checkValid(BaseWrapperManagedConnection.java:364)
        at org.jboss.resource.adapter.jdbc.local.LocalManagedConnectionFactory.matchManagedConnections(LocalManagedConnectionFactory.java:402)
        at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:225)
        at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:689)
        at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:404)
        at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:424)
        at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:496)
        at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:941)
        at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89)