@Entity
@Table(name = "order")
public class Order {
	private Long idOrder;
...//getters setters
}

@Entity
@Table(name = "str_order")
public class StrOrder {
	private Long idStrOrder;
	private Long idFkOrder;
	private String col;
...//getters setters
}

Order order;
order = (Order) session.get(Order.class, (long) 1);
Set<StrOrder> listStrOrder;
listStrOrder = order.getListStrOrder();

	System.out.println("StrOrder:\n");
	Set<StrOrder> sets = order.getListStrOrder();
	Iterator iterator = sets.iterator();
	while (iterator.hasNext()) {
		StrOrder element = (StrOrder) iterator.next();
		System.out.println(element.getCol());
	}

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "STOCK_ID", nullable = false)
public Stock getStock() {
	return this.stock;
}

mappedBy="order"

Caused by: org.hibernate.AnnotationException: mappedBy reference an unknown target entity property: artifactID.domain.StrOrder.order in artifactID.domain.Order.listStrOrder

Initial SessionFactory creation failed.org.hibernate.MappingException: Repeated column in mapping for entity: artifactID.domain.StrOrder column: id_fk_order (should be mapped with insert="false" update="false")

@Column(name = "id_fk_order", nullable = false)
public Long getIdFkOrder() {
	return idFkOrder;
}

@Entity
@Table(name = "str_order")
public class StrOrder {
	private Long idStrOrder;
//	private Long idFkOrder;
	private String col;

	@Id
	@GeneratedValue
	@Column(name = "id_str_order", nullable = false)
	public Long getIdStrOrder() {
		return idStrOrder;
	}

	public void setIdStrOrder(Long idStrOrder) {
		this.idStrOrder = idStrOrder;
	}

//	@Column(name = "id_fk_order", nullable = false)
//	public Long getIdFkOrder() {
//		return idFkOrder;
//	}
//
//	public void setIdFkOrder(Long idFkOrder) {
//		this.idFkOrder = idFkOrder;
//	}

	@Column(name = "col", nullable = false)
	public String getCol() {
		return col;
	}

	public void setCol(String col) {
		this.col = col;
	}
}

@Entity
@Table(name = "order")
public class Order implements Serializable{
	private Long idOrder;
	private String col;
	private Set<StrOrder> listStrOrder;

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	@Column(name = "id_order", nullable = false)
	public Long getIdOrder() {
		return idOrder;
	}

	public void setIdOrder(Long idOrder) {
		this.idOrder = idOrder;
	}

	@Column(name = "col", nullable = false)
	public String getCol() {
		return col;
	}

	public void setCol(String col) {
		this.col = col;
	}
	
	@OneToMany(fetch = FetchType.LAZY)
	@JoinColumn(name = "id_fk_order", nullable = false)
	public Set<StrOrder> getListStrOrder() {
		return listStrOrder;

	}

	public void setListStrOrder(Set<StrOrder> listStrOrder) {
		this.listStrOrder = listStrOrder;
	}
}

public class Main {

	public static void main(String[] args) {
		System.out.println("Hibernate one to many (Annotation)");
		Session session = HibernateUtil.getSessionFactory().openSession();
		

			Order order = null;
			order = (Order) session.get(Order.class, (long) 1);
			System.out.println("Order:");
			System.out.println(order.getCol());

			System.out.println("StrOrder:\n");
			Set<StrOrder> sets = order.getListStrOrder();
			Iterator iterator = sets.iterator();
			while (iterator.hasNext()) {
				StrOrder element = (StrOrder) iterator.next();
				System.out.println(element.getCol());
			}
	}
}

CREATE TABLE `order` (
  `id_order` int(11) NOT NULL AUTO_INCREMENT,
  `col` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`id_order`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

CREATE TABLE `str_order` (
  `id_str_order` int(11) NOT NULL AUTO_INCREMENT,
  `id_fk_order` int(11) NOT NULL,
  `col` varchar(45) NOT NULL,
  PRIMARY KEY (`id_str_order`),
  KEY `id_fk_order` (`id_fk_order`),
  CONSTRAINT `id_fk_order` FOREIGN KEY (`id_fk_order`) REFERENCES `order` (`id_order`) ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8