lazy type Exception when trying to get resultset [duplicate]

I am trying to get the orders by using the getOrders(String domain) function from domain DAO this is the code:

Set<Order> orders;
orders = domainService.getOrders('google.com');

but I keep getting this error

failed to lazily initialize a collection of role: com.latinon.reportator.model.Domain.ordersDomain, could not initialize proxy - no Session

which one is the correct way to set the lazy type without getting the error

pojos

domain

@Entity
@Table(name="Domain")
public class Domain {

    private Set<Order> ordersDomain = new HashSet<Order>(0);
    private Set<User> userDomain = new HashSet<User>(0);

    @ManyToMany(fetch=FetchType.LAZY)
    @JoinTable(name="Order_Domain", joinColumns={
            @JoinColumn(name="Order_Domain_Domain_id")
    },inverseJoinColumns={
            @JoinColumn(name="Order_Domain_Order_id", nullable=false,updatable=false)
    })
    public Set<Order> getOrdersDomain() {
        return ordersDomain;
    }
    public void setOrdersDomain(Set<Order> ordersDomain) {
        this.ordersDomain = ordersDomain;
    }
}

order

@Entity
@Table(name="Order")
public class Order {

    private Set<Domain> orderDomains = new HashSet<Domain>(0); 

    @ManyToMany(fetch=FetchType.LAZY)
    @JoinTable(name="Order_Domain", joinColumns={
            @JoinColumn(name="Order_Domain_Order_id",nullable=false,updatable=false)
    }, inverseJoinColumns={
            @JoinColumn(name="Order_Domain_Domain_id",nullable=false,updatable=false)
    })
    public Set<Domain> getOrderDomains() {
        return orderDomains;
    }
    public Set<Domain> getOrderDomains() {
        return orderDomains;
    }
}

DAOs

Domain

public interface DomainDAO {
    public void saveDomain(Domain domain);
    public void updateDomain(Domain domain);
    public Domain getDomainById(Integer id);
    public Domain getDomain(String domain);
    public void deleteDomain(Integer id);
    public Set<Order> getOrders(String domain);
}

Order

public interface OrderDAO {
    public void saveOrder(Order order);
    public void updateOrder(Order order);
    public Order getOrderById(Integer id);
    public void deleteOrder(Integer id);
    public Order getOrderByAdUnit(String adUnitId);
}

servicios

domain

public interface DomainService {
    public void saveDomain(Domain domain);
    public void updateDomain(Domain domain);
    public Domain getDomainById(Integer id);
    public void deleteDomain(Integer id);
    public Domain getDomain(String domain);
    public Set<Order> getOrders(String domain);
} 

domain service implementation

@Service
public class DomainServiceImpl implements DomainService {
    private DomainDAO domainDao;
    public DomainDAO getDomainDao() {
        return domainDao;
    }
    public void setDomainDao(DomainDAO domainDao) {
        this.domainDao = domainDao;
    }

    public DomainServiceImpl() {
        // TODO Auto-generated constructor stub
    }
    @Transactional
    public Set<Order> getOrders(String domain) {
        Domain domainAux = this.domainDao.getDomain(domain);
        return domainAux.getOrdersDomain();
    }
}

order

public interface OrderService {
    public void saveOrder(Order order);
    public void updateOrder(Order order);
    public Order getOrderById(Integer id);
    public void deleteOrder(Integer id);
    public Order getOrderByAdUnit(String adUnitId);
}

order service implementation

@Service
public class OrderServiceImpl implements OrderService {

    private OrderDAO orderDAO;

    public OrderDAO getOrderDAO() {
        return orderDAO;
    }
    public void setOrderDAO(OrderDAO orderDAO) {
        this.orderDAO = orderDAO;
    }

    public OrderServiceImpl() {
        // TODO Auto-generated constructor stub
    }
    @Transactional
    public Order getOrderByAdUnit(String adUnitId) {
        return this.orderDAO.getOrderByAdUnit(adUnitId);
    }
}