==================
EL Warning]: 2018-03-19 19:22:23.207--UnitOfWork(1047460718)--
java.lang.ClassCastException:
org.apache.tomcat.dbcp.dbcp2.PoolingDataSource$PoolGuardConnectionWrapper
cannot be cast to oracle.jdbc.OracleConnection
19:23:49.838 DEBUG o.t.c.d.PartyRequestSearchDAOImpl -
PartyRequestViewDAOImpl:retrieveSearchResults : Exception while retrieving
data from DB
javax.persistence.PersistenceException: java.lang.ClassCastException:
org.apache.tomcat.dbcp.dbcp2.PoolingDataSource$PoolGuardConnectionWrapper
cannot be cast to oracle.jdbc.OracleConnection
   at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:484)
   at sun.reflect.GeneratedMethodAccessor83.invoke(Unknown Source)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:497)
   at org.springframework.orm.jpa.SharedEntityManagerCreator$DeferredQueryInvocationHandler.invoke(SharedEntityManagerCreator.java:372)

----
----

Caused by: java.lang.ClassCastException:
org.apache.tomcat.dbcp.dbcp2.PoolingDataSource$PoolGuardConnectionWrapper
cannot be cast to oracle.jdbc.OracleConnection
   at oracle.sql.TIMESTAMPLTZ.initDbTimeZone(TIMESTAMPLTZ.java:1465)
   at oracle.sql.TIMESTAMPLTZ.toCalendar(TIMESTAMPLTZ.java:1229)
   at oracle.sql.TIMESTAMPLTZ.toTimestamp(TIMESTAMPLTZ.java:1180)
   at oracle.sql.TIMESTAMPLTZ.toTimestamp(TIMESTAMPLTZ.java:721)
   at org.eclipse.persistence.platform.database.oracle.Oracle9Platform.getTIMESTAMPLTZFromResultSet(Oracle9Platform.java:263)

===========================

package org.mypackage.jpa.eclipselink.support;

import java.sql.Connection;
import java.sql.SQLException;
import oracle.jdbc.OracleConnection;
import org.eclipse.persistence.platform.server.ServerPlatformBase;
import org.eclipse.persistence.sessions.DatabaseSession;
import org.eclipse.persistence.transaction.JTATransactionController;
import org.springframework.beans.factory.annotation.Autowired;


public class TomcatServerPlatform extends ServerPlatformBase {

   @Autowired
   JTATransactionController jTATransactionController;

   public TomcatServerPlatform(DatabaseSession newDatabaseSession) {
          super(newDatabaseSession);
   }

   @Override
   public Class getExternalTransactionControllerClass() {
          return null; //jTATransactionController.getClass();
   }

   @Override
   public Connection unwrapConnection(Connection connection) {

          OracleConnection oracleConnection = null;

          try {
                 if (connection.isWrapperFor(OracleConnection.class)) {
                  oracleConnection = connection.unwrap(OracleConnection.class);
              }
          } catch (SQLException e) {

                 e.printStackTrace();
          }

          return connection;
   }
}

<GlobalNamingResources>
<Resource accessToUnderlyingConnectionAllowed="true" auth="Container" driverClassName="oracle.jdbc.driver.OracleDriver" global="jdbc/oracle_DS" maxIdle="10" maxTotal="25" name=" jdbc/oracle_DS " password="****" type="javax.sql.DataSource" url="jdbc:oracle:thin:@**** " username="**** "/>

<persistence-unit name="BasePersistenceUnit" transaction-type="JTA">
          <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
          <jta-data-source> jdbc/oracle_DS </jta-data-source>
          <!-- Need to add data object here -->
          <class>org.myproj.model.dataobject.Rqst</class>
          <class>org. myproj.model.dataobject.RqstHist</class>
          <exclude-unlisted-classes>true</exclude-unlisted-classes>

          <properties>
                 <!-- <property name="eclipselink.target-server" value="WebLogic_10" /> -->
                 <property name="eclipselink.target-server" value=" org.mypackage.jpa.eclipselink.support.TomcatServerPlatform" />
                 <property name="eclipselink.target-database" value="org.eclipse.persistence.platform.database.oracle.Oracle11Platform"/>
                 <property name="eclipselink.logging.level" value="WARNING" />
                 <property name="eclipselink.persistence-context.flush-mode" value="COMMIT" />
                 <property name="eclipselink.persistence-context.close-on-commit" value="true" />
                 <property name="eclipselink.cache.shared.default" value="false" />
          </properties>
   </persistence-unit>