@OneToMany独立实体已传递以持久化

Question

I face this error when inserting in Order table

org.springframework.dao.InvalidDataAccessApiUsageException: detached entity passed to persist: org.vi.entities.LineItem; nested exception is org.hibernate.PersistentObjectException: detached entity passed to persist: org.vi.entities.LineItem

Mapping this is how i map my classes :

@Entity
public class Order implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name = "id", updatable = false, nullable = false)
    private Long id;
    @Column(name = "delivered", nullable = false)
    private boolean delivered;
    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    @JoinColumn(name = "fk_order")
    private Set<LineItem> lineItems= new HashSet<LineItem>();
}
@Entity
public class LineItem implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name = "id", updatable = false, nullable = false)
    private Long id;
    @Column(name="quantity", nullable = false)
    private int quantity;
    @ManyToOne
    private Product product;
}
@Entity
public class Product implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    @Column(name = "id", updatable = false, nullable = false)
    private Long id;    
    @Column(name = "reference", unique = true, nullable = false)
    private String reference;
    @Column(name = "price", nullable = false)
    private double price;
}

Inserting in my tables this is how i save new rows in my tables

Product p1 = new Product("reference1",10000);
Product p2 = new Product("reference2",20000;
productRepository.save(p1);productRepository.save(p2);

LineItem li1 = new LineItem(6, p1);
LineItem li1 = new LineItem(9, p2);
lineItemRepository.save(li1);lineItemRepository.save(li2);

Set<LineItem> lineItems1= new HashSet<LineItem>();
lineItems1.add(li1);
lineItems1.add(li2);

Order o1 = new Order(false,lineItems1);
orderRepository.save(o1);

Could you please help me if there is a problem in the mapping?

Answer 1

Try below:

Order o1 = new Order(false,lineItems1);
o1.getLineItems().add(new LineItem(6, p1););
o1.getLineItems().add(new LineItem(6, p1););
orderRepository.save(o1);

Instead of creating a new HashSet use the existing one from order since that's the object that hibernate is tracking.

Answer 2

I think you should try to remove the lineItemRepository.save(li1);lineItemRepository.save(li2); line, since CascadeType.ALL will persist te Set<LineItem> also.

Answer 3

Replace this code,

 LineItem li1 = new LineItem(6, p1);
    LineItem li2 = new LineItem(9, p2);
    lineItemRepository.save(li1);lineItemRepository.save(li2);

if any issue inform.