java - JPA ManyToMany 持续存在

Question

我有一个 NOTIFICATION 表，其中包含一个 ManyToMany 关联:

@Entity
@Table(name="NOTIFICATION")
@NamedQuery(name="Notification.findAll", query="SELECT f FROM Notification f")
public class Notification {

/** SOME COLUMN DEFINITION NOT IMPORTANT FOR MY CASE
    COD, DATE, ID_THEME, ID_TYP, IC_ARCH, ID_CLIENT, INFOS, NAME, TITRE_NOT, ID_NOT
**/

        @ManyToMany
        @JoinTable(
            name="PJ_PAR_NOTIF"
            , joinColumns={
                @JoinColumn(name="ID_NOTIF")
                }
            , inverseJoinColumns={
                @JoinColumn(name="ID_PJ_GEN")
                }
            )
        private List<PiecesJointesGen> piecesJointesGens;
}

因此，我有一个名为 PJ_PAR_NOTIF 的关联表。

我尝试保留一个Notification实体。这是来自值对象的piecesJointesGens初始化:

@PersistenceContext(unitName="pu/middle")

private EntityManager entityMgr;

FoaNotification lFoaNotification = new FoaNotification();

for(PieceJointeGenVO lPJGenVO : pNotificationVO.getPiecesJointes()){
        PiecesJointesGen lPiecesJointesGen = new PiecesJointesGen();
        lPiecesJointesGen.setLienPjGen(lPJGenVO.getLienPieceJointeGen());
        lPiecesJointesGen.setIdPjGen(lPJGenVO.getIdPieceJointeGen());
        lNotification.getFoaPiecesJointesGens().add(lFoaPiecesJointesGen);
}

entityMgr.persist(pNotification);

坚持不起作用。 JPA 为我的通知对象生成第一个插入，没问题:

insert 
into
    NOTIFICATION
    (COD, DATE, ID_THEME, ID_TYP, IC_ARCH, ID_CLIENT, INFOS, NAME, TITRE_NOT, ID_NOT) 
values
    (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)

然后，JPA 尝试在我的关联表中插入值，但pieceJointesGen 目前不存在:

insert 
into
    PJ_PAR_NOTIF
    (ID_NOTIF, ID_PJ_GEN) 
values
    (?, ?)

所以，我有这个错误:

GRAVE: EJB Exception: : java.lang.IllegalStateException: org.hibernate.TransientObjectException: object references an unsaved transient instance - save the transient instance before flushing: com.entities.PiecesJointesGen

有没有办法告诉 JPA 在 PJ_PAR_NOTIF 插入之前插入 piecesJointesGen ？

Answer 1

修改 piecesJointesGens 映射到 @ManyToMany(cascade = CascadeType.PERSIST)。