import java.lang.reflect.Method;
import java.sql.Connection;
import oracle.jdbc.OracleConnection;

public class Connector {
    private static Method getUnderlyingConnectionMethod;
    public static OracleConnection getOracleConnection(Connection connection) throws Exception
    {
        if (connection == null)return null;
        if (connection instanceof OracleConnection) return (OracleConnection) connection;
        if (getUnderlyingConnectionMethod == null)
            getUnderlyingConnectionMethod = connection.getClass().getMethod("getUnderlyingConnection", (Class[])null);
        return (OracleConnection) getUnderlyingConnectionMethod.invoke(connection, (Object[])null);
    }
}

<module xmlns="urn:jboss:module:1.1" name="com.oracle">
  <resources>
    <resource-root path="ojdbc7_g.jar"/>
    <resource-root path="orai18n.jar"/>
  </resources>
  <dependencies>
    <module name="javax.api"/>
    <module name="javax.transaction.api"/>
  </dependencies>
</module>

        <subsystem xmlns="urn:jboss:domain:datasources:3.0">
            <datasources>
                <datasource jndi-name="java:jboss/datasources/my-local-ds" pool-name="my-local-ds" enabled="true">
                    <connection-url>jdbc:oracle:thin:@(DESCRIPTION = (ADDRESS_LIST =  (ADDRESS = (PROTOCOL = TCP) (HOST = myhost) (PORT = 1521))) (CONNECT_DATA =  (SID = mySID)))</connection-url>
                    <driver>oracle</driver>
                    <pool>
                        <min-pool-size>1</min-pool-size>
                        <max-pool-size>5</max-pool-size>
                        <prefill>true</prefill>
                    </pool>
                    <security>
                        <user-name>myUser</user-name>
                        <password>myPasswd</password>
                    </security>
                </datasource>
                <datasource jndi-name="java:jboss/datasources/ExampleDS" pool-name="ExampleDS" enabled="true" use-java-context="true">
                    <connection-url>jdbc:h2:mem:test;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE</connection-url>
                    <driver>h2</driver>
                    <security>
                        <user-name>sa</user-name>
                        <password>sa</password>
                    </security>
                </datasource>
                <drivers>
                    <driver name="oracle" module="com.oracle">
                        <driver-class>oracle.jdbc.driver.OracleDriver</driver-class>
                    </driver>
                    <driver name="h2" module="com.h2database.h2">
                        <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
                    </driver>
                </drivers>
            </datasources>
        </subsystem>

import java.sql.Connection;
import javax.annotation.Resource;
import javax.ejb.EJB;
import javax.ejb.SessionContext;
import javax.sql.DataSource;
import oracle.jdbc.OracleConnection;

@javax.ejb.Stateless
@javax.ejb.TransactionManagement(value = javax.ejb.TransactionManagementType.CONTAINER)
@javax.ejb.TransactionAttribute(value = javax.ejb.TransactionAttributeType.REQUIRED)
public class MySLSBean implements MySLSBRemoteIf{
	@Resource
	private SessionContext ctx;
    @EJB(lookup = "java:jboss/datasources/my-local-ds")
    private DataSource ds;
    
    @Override
    public void doSomthing(){
        OracleConnection c = null;
        try{
            c = getConncetion(ds);
            CallableStatement cs = c.prepareCall("<вызов процедуры>");
        }catch(Exception e){
        }finally{
            cs.close();
            c.close();
        } 
        
    }
    private OracleConnection getConnection(DataSource ds){
        Connection c = ds.getConnection();
        return Connector.getOracleConnection(c);
    }
}

Caused by: java.lang.NoClassDefFoundError: oracle/jdbc/OracleConnection
	at ru.mypakage.Connector.getOracleConnection(Connector.java: <номер строки>)
 
  ...... 
 и т.д.
   

Dependencies: com.oracle org.jboss.ironjacamar.jdbcadapters