public class InmateImpl extends InmateBaseImpl {
 /*
  * NOTE FOR DEVELOPERS:
  *
  * Never reference this class directly. All methods that expect a Inmate Entity model instance should use the {@link sa.gov.nafethah.service.model.Inmate} interface instead.
  */
 public InmateImpl() {
 }
 
 public User getUser() throws PortalException, SystemException{
  long userId = this.getInmateId();
  
  if(userId == 0){
   return null;
  }
  
  return UserLocalServiceUtil.getUser(userId);
 }
} 

// then you build service