将列表的子元素另存为父元素不能正确保存

Question

我有一个A类，其中包含B类对象的列表，当我保存A时，仅保存B的ID，没有其他属性

@Entity

表结构：

Class A{
@Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    private String id;
    private String name;
    private String address1;
    private String address2;
    @JoinColumn
    @ManyToOne
    private AGroup aGroup;
    @JoinColumn
    @ManyToOne
    private Currency currency;
    private Date createdOn;
    private Date updatedOn;
    @OneToMany(mappedBy = "a", cascade = CascadeType.PERSIST)
    private Collection<B> b;
}

Class B{
@Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    private String id;
    @ManyToOne
    @JoinColumn
    private A a;
    private Date createdOn;
    private Date updatedOn;
}

在保存A之前，我看到B的列表对于对象A是正确的，但是在保存之后，只为B保存了ID，尽管它也应该正确保存。