"异常是 javax.persistence.EntityNotFoundException：无法找到 id 为“xx”的实体类"

Question

我知道我在做一些时髦的事情，而且我承认在 IDE 中进行调试、交换注释和阅读其他人的问题和答案的花费比我愿意承认的要多，但我真的失败了。 所以我愿意在这个阶段接受答复。

队列实体：

@NoArgsConstructor
@AllArgsConstructor
@Entity (name = "Queue")
@Table(name = "queues")
public class Queue implements Serializable {

    @Id
    @Column(name = "uuid", unique = true, nullable = false)
    private UUID uuid = UUID.randomUUID();

    @Column(name = "name", nullable = false)
    private String name;

    @OneToOne(optional = false)
    @JoinColumn(name = "head", nullable = false, unique = true)
    private QueueItem head;

    @OneToOne(optional = false)
    @JoinColumn(name = "tail", nullable = false, unique = true)
    private QueueItem tail;

    @OneToMany(mappedBy = "queue", cascade = CascadeType.ALL)
    private List<QueueItem> queueItems = new ArrayList<>();

\\getters & setters