nye instanser via Spring

NewSpringBean

Dette er hva jeg har gjort nå, etter å ha prøvd mye annet rart......;-)
applicationContext:
<beans>
<bean id="wsMonitoringServiceFactoryBean" class="no.soliditet.webservices.monitor1.helper.WSMonitoringService" singleton="true" factory-method="getInstance">
<property name="serviceClass" value="no.lindorff.pro.server.MonitoringServiceImpl"/>
   </bean>
</beans>

Java, interface +impl:
public class MonitoringServiceImpl implements MonitoringService

Java factory/singleton...whatever:
public class WSMonitoringService {
 private static WSMonitoringService instance;
   private String serviceClass;
  private Class<MonitoringService> clazz;
   private WSMonitoringService() {
   }
public static synchronized WSMonitoringService getInstance() {
      if (instance == null) {
         instance = new WSMonitoringService();
      }
      return instance;
   }
   public MonitoringService getMonitoringService() {
      try {
         MonitoringService myService = clazz.newInstance();
         return myService;
      }
      catch (Exception e) {
         log.error("Unable to instantiate monitoringservice object.", e);
         throw new RuntimeException(e);
      }
   }

   public void setServiceClass(String serviceClass) {
      this.serviceClass = serviceClass;
      clazz = getClazz();
   }

   private Class<MonitoringService> getClazz() {
      try {
         //noinspection unchecked
         return (Class<MonitoringService>)Class.forName(serviceClass);
      }
      catch (Exception e) {
         log.error("Unable to instantiate monitoringservice object.", e);
         throw new RuntimeException(e);
      }
   }

}