我有两个JPA实体,就像这样:
@Entity
class Foo {
@Id
private long id;
// ...
}
@Entity
class Bar {
@ElementCollection(targetClass = String.class, fetch = FetchType.LAZY)
@MapKeyJoinColumn(name = "foo_id", referencedColumnName = "id")
@MapKeyClass(Foo.class)
@Column(name = "content")
@CollectionTable(name = "bar_foo_content",
joinColumns = @JoinColumn(name = "bar_id", referencedColumnName = "id"))
@ManyToMany(cascade = CascadeType.ALL)
private Map<Foo, String> fooContent = Maps.newHashMap();
// ...
}
你可以看到,fooContent
字段在 Bar
和 Foo
之间形成了多对多的关系,因此我认为使用 @ManyToMany
来指定字段的级联是合适的。但是,当试图将一个带有一些 Foo → String
值的映射的 Bar
持久化时,我会收到以下异常:
javax.persistence.RollbackException: java.lang.IllegalStateException: During synchronization a new object was found through a relationship that was not marked cascade PERSIST: <<instance of Foo>>
显然,EclipseLink没有级联持久化我的Foo
实例。我应该如何注释fooContent
以使级联持久化工作?
Foo
是什么样子?异常看起来像是Foo
和另一个实体之间存在问题。 - Uooo