How to return an ArrayList object from web service

.EndpointReference ;
import org.apache.axis2.client.Options;
import org.apache.axis2.rpc.client.RPCServiceClient;
import org.apache.log4j.Logger;

import gr.ntua.netmode.myPaper.*;

public class topologyRPCClient {
   
    private static Logger log =Logger.getLogger(topologyRPCClient.class);
       
    public static void main(String[] args1) throws AxisFault {

            RPCServiceClient serviceClient = new RPCServiceClient();
            Options options = serviceClient.getOptions();
            EndpointReference targetEPR = new EndpointReference("http://localhost:8080/axis2/services/TopologyService ");
            options.setTo(targetEPR);

            QName opGetNode =new QName(" http://service.netmode.ntua.gr/xsd", "getLocation");
            log.debug(opGetNode);
           
            Object[] opGetNodeArgs = new Object[] { };
            Class[] returnTypes = new Class[] { List.class };
            Object[] response = serviceClient.invokeBlocking (opGetNode, opGetNodeArgs, returnTypes);
          
            List result = (List) response[0];
            Location k=(Location) result.get(1);
            System.out.println(k.getCity());
           

            }
                                 
        }
}


and this is the service code:

public List getLocation(Integer id) throws Exception  {
   
        List <Location> n=null;
        Location x=null;
        String y=null;
       
        Transaction tx = null;
        SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session =sessionFactory.openSession();
       
        System.err.println(session.isConnected());
        System.err.println(session.isOpen());
       
        try {
            tx = session.beginTransaction();
           
            System.err.println(tx.isActive());
           
            n= session.createQuery("from Location as location").list();
           
           
            x=n.get(2);
            y=x.getName();
           
            log.debug(n);
            tx.commit();
           
            System.out.println(n);
            System.out.println();
            System.out.println(y);
            System.out.println(x.getCountry());
            System.out.println(x.getAltitude());
            System.out.println(x.getEmail_address());
            System.out.println ();
        }
         catch (HibernateException e) {
            e.printStackTrace();
            if (tx != null && tx.isActive())
                tx.rollback();
        }
         
        return n;
    }