TransientObjectException - 對象引用未保存的瞬態實例 - 在刷新之前保存瞬態實例

Question

對於我的問題，我遇到了一些很好的可能答案，但這是關於從 Hibernate 3.4.0GA 升級到 Hibernate 4.1.8。 所以這曾經在以前的版本下工作，我已經在高低搜索了為什么它在這個新版本中被打破。

我得到一個

org.hibernate.TransientObjectException：對象引用未保存的瞬態實例 - 在刷新之前保存瞬態實例：com.test.server.domain.model.NoteItem.note -> com.test.server.domain.model.Note

任何幫助都會很棒。

這是我的課。

@MappedSuperclass
public abstract class EntityBase implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "ID")
    protected Long id;

    @Version
    @Column(name = "VERSION")
    protected Long version; 

    public Long getId() {
        return id;
    }

    public Long getVersion() {
        return version;
    }

    protected static final EntityManager entityManager() {
        return EntityManagerUtil.getEntityManager();
    }
}

@Entity
@Table(name = "WORK_BOOK")
public class WorkBook extends EntityBase {
    private static final long serialVersionUID = 1L;

    @OneToOne(cascade = CascadeType.ALL)
    @JoinColumn(name = "NOTE_ID")
    private Note note;

    public WorkBook() {
        super();
    }

    public Note getNote() {
        return note;
    }

    public void setNote(Note note) {
        this.note = note;
    }

    public WorkBook persist() {
        EntityManager em = entityManager();
        EntityTransaction tx = em.getTransaction();

        if (tx.isActive()) {
            return em.merge(this);
        } else {
            tx.begin();
            WorkBook saved = em.merge(this);
            tx.commit();
            return saved;
        }
    }
}

@Entity
@Table(name = "NOTE")
public class Note extends EntityBase {
    private static final long serialVersionUID = 1L;

    @OneToOne(mappedBy = "note")
    private WorkBook workBook;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "note")
    private List<NoteItem> notes = new ArrayList<NoteItem>();

    public WorkBook getWorkBook() {
        return workBook;
    }

    public List<NoteItem> getNotes() {
        return notes;
    }

    public void setWorkBook(WorkBook workBook) {
        this.workBook = workBook;
    }

    public void setNotes(List<NoteItem> notes) {
        if (notes != null) {
            for (NoteItem ni : notes) {
                ni.setNote(this);               
            }
        }

        this.notes = notes;
    }
}   

@Entity
@Table(name = "NOTE_ITEM")
public class NoteItem extends EntityBase {
    private static final long serialVersionUID = 1L;

    @Column(name = "NOTE_NAME")
    private String noteName;

    @Column(name = "NOTE_TEXT")
    private String noteText;

    @Column(name = "NOTE_DATE")
    private Date noteDate;

    @Column(name = "NOTE_CREATOR")
    private String noteCreator;

    @Column(name = "NOTE_CREATOR_ID")
    private Integer noteCreatorId;

    @ManyToOne
    @JoinColumn(name = "NOTE_ID", updatable = true)
    private Note note;

    public String getNoteName() {
        return noteName;
    }

    public void setNoteName(String noteName) {
        this.noteName = noteName;
    }

    public String getNoteText() {
        return noteText;
    }

    public void setNoteText(String noteText) {
        this.noteText = noteText;
    }

    public Date getNoteDate() {
        return noteDate;
    }

    public void setNoteDate(Date noteDate) {
        this.noteDate = noteDate;
    }

    public String getNoteCreator() {
        return noteCreator;
    }

    public void setNoteCreator(String noteCreator) {
        this.noteCreator = noteCreator;
    }

    public Integer getNoteCreatorId() {
        return noteCreatorId;
    }

    public void setNoteCreatorId(Integer noteCreatorId) {
        this.noteCreatorId = noteCreatorId;
    }

    public Note getNote() {
        return note;
    }

    public void setNote(Note note) {
        this.note = note;
    }

    public NoteItem create() {
        return new NoteItem();
    }
}   

Answer 1

NoteItem引用一個臨時的（尚未保存的） Note實例，該實例之前必須保存。 因此，請在屬性注釋上指定“Cascade.all”或首先在注釋上調用 saveorupdate。

Answer 2

在引入樂觀鎖定（@Version）后，我對所有 PUT HTTP 事務都面臨同樣的錯誤

在更新實體時，必須發送該實體的 id 和版本。 如果任何實體字段與其他實體相關，那么對於該字段，我們也應該提供 id 和 version 值，而不是 JPA 嘗試首先保留該相關實體

示例：我們有兩個實體 --> Vehicle (id,Car,version) ; Car (id, version, brand) to update/persist Vehicle 實體確保 Vehicle 實體中的 Car 字段提供了 id 和 version 字段