如何在春季数据休息中存储 List<List<Integer>>？

Question

我想要一个可以序列化为这样的对象的模型

{
  frames = [
    [0,1,2,3],
    [4,5,4,3],
    [2,1,0]
  ]
}

现在我不知道该怎么做，所以我这样做了

 * Created by michael on 26/08/15.
 */
@Entity
public class Frame {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;

    public Frame(List<Integer> data) {
        this.data = data;
    }

    public Frame() {}

    public List<Integer> getData() {

        return data;
    }

    public void setData(List<Integer> data) {
        this.data = data;
    }
    @ElementCollection
    @NotNull
    List<Integer> data;
}

@Entity
public class DacChannel {
    @Id
    private int number;
    @OneToMany(cascade = CascadeType.ALL)

    @NotNull
    private List<Frame> frames;

    public DacChannel(int number, List<Frame> frames) {
        setNumber(number);
        setFrames(frames);
    }

    public DacChannel() {
    }

    public int getNumber() {

        return number;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public List<Frame> getFrames() {
        return frames;
    }

    public void setFrames(List<Frame> frames) {
        this.frames = frames;
    }

}

但它也不能正常工作。我可以通过发布请求创建此实体

{
    "number": 0,
    "frames": [
        {"data": [1,2,3]},
        {"data": [3,4,5]}
    ]
}

但不知何故

{
    "number": 1,
    "frames": [
        {"data": [1,2,3]},
        {"data": [3,4,5]}
    ]
}

给我一​​个错误。

nested exception is javax.validation.ConstraintViolationException: Validation failed for classes [demo.model.board.DacChannel] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=frames, rootBeanClass=class demo.model.board.DacChannel, messageTemplate='{javax.validation.constraints.NotNull.message}'}
]] with root cause

javax.validation.ConstraintViolationException: Validation failed for classes [demo.model.board.DacChannel] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=frames, rootBeanClass=class demo.model.board.DacChannel, messageTemplate='{javax.validation.constraints.NotNull.message}'}
]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:160)
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreInsert(BeanValidationEventListener.java:95)
    at org.hibernate.action.internal.EntityInsertAction.preInsert(EntityInsertAction.java:218)
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:97)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:465)
    at org.hibernate.engine.spi.ActionQueue.executeInserts(ActionQueue.java:337)
    at org.hibernate.engine.spi.ActionQueue.addInsertAction(ActionQueue.java:176)
    at org.hibernate.engine.spi.ActionQueue.addAction(ActionQueue.java:216)
    at org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction(AbstractSaveEventListener.java:334)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:289)
    at org.hibernate.event.internal.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:195)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:126)
    at org.hibernate.jpa.event.internal.core.JpaMergeEventListener.saveWithGeneratedId(JpaMergeEventListener.java:73)
    at org.hibernate.event.internal.DefaultMergeEventListener.saveTransientEntity(DefaultMergeEventListener.java:271)
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsTransient(DefaultMergeEventListener.java:251)
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:189)
    at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:886)
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:868)
    at org.hibernate.engine.spi.CascadingActions$6.cascade(CascadingActions.java:277)
    at org.hibernate.engine.internal.Cascade.cascadeToOne(Cascade.java:350)
    at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:293)
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:161)
    at org.hibernate.engine.internal.Cascade.cascadeCollectionElements(Cascade.java:379)
    at org.hibernate.engine.internal.Cascade.cascadeCollection(Cascade.java:319)
    at org.hibernate.engine.internal.Cascade.cascadeAssociation(Cascade.java:296)
    at org.hibernate.engine.internal.Cascade.cascadeProperty(Cascade.java:161)
    at org.hibernate.engine.internal.Cascade.cascade(Cascade.java:118)
    at org.hibernate.event.internal.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:470)
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsTransient(DefaultMergeEventListener.java:255)
    at org.hibernate.event.internal.DefaultMergeEventListener.entityIsDetached(DefaultMergeEventListener.java:317)
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:186)
    at org.hibernate.event.internal.DefaultMergeEventListener.onMerge(DefaultMergeEventListener.java:85)
    at org.hibernate.internal.SessionImpl.fireMerge(SessionImpl.java:876)
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:858)
    at org.hibernate.internal.SessionImpl.merge(SessionImpl.java:863)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:1196)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)

所以我想“你在说什么 null，我已经在请求正文中包含了所有属性！”。我不明白发生了什么。

另外，我可以用 jpa 做我最初想做的事情吗？也许使用@Lob 之类的？或者也许我可以用 mongodb 轻松做到这一点？我现在使用 postres 和 h2（用于测试）。

编辑1

经过一些实验，我发现在此处删除 NotNull 注释后，一切正常。不过，我的问题是保持不变。我可以做我最初想做的事情（使用 mongodb 或 @Lob 吗？）。我得到这个错误的原因是什么？我不想删除 NonNull 注释。

@ElementCollection 列出数据；

Answer 1

首先，无法正常工作的是 bean 验证，而不是您存储数据的方式。

您尝试保存的对象没有正确设置的帧列表。 可能没有调用dacChannel.setFrames(…)。

解决这个问题，应该没问题。