java - PersistentObjectException : detached entity passed to persist: com. 边缘.le.domain.Tag

Question

我有一个 Goal 实体，它与 Tag 具有多对多关系。这里的Goal是我拥有的实体。我正在使用 JPA 来坚持。当我使用现有的 Tag 保存 Goal 时，它给出了 PersistentObjectException 。其他场景，例如使用新的 Tag 的 New Gaol 、使用现有的 Tag 编辑现有的 Goal 、使用新的 Tag 的现有 Goal 都工作正常。下面是我的实体结构:

目标.java

@Entity
@Table(name = "goal")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
@Document(indexName = "goal")
public class Goal implements Serializable {

private static final long serialVersionUID = 1L;

@ManyToMany(cascade = {
         CascadeType.MERGE,
         CascadeType.PERSIST,
    },targetEntity = Tag.class)
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
@JoinTable(name = "goal_tag",
           joinColumns = @JoinColumn(name="goals_id",      referencedColumnName="ID"),
           inverseJoinColumns = @JoinColumn(name="tags_id", referencedColumnName="ID"))
private Set<Tag> tags = new HashSet<>();

 //getters &  setters

标签.java

 @Entity
 @Table(name = "tag")
 @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
 @Document(indexName = "tag")
 public class Tag implements Serializable {

private static final long serialVersionUID = 1L;

@Id
private String id;

@ManyToMany(mappedBy = "tags")
@JsonIgnore
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
private Set<Goal> goals = new HashSet<>();

 //getters & setters

GoaServiceImpl.java save() 方法

 public class GoalServiceImpl implements GoalService{

private final Logger log = LoggerFactory.getLogger(GoalServiceImpl.class);

@Inject
private GoalRepository goalRepository;

@Inject
private GoalMapper goalMapper;

@Inject
private GoalSearchRepository goalSearchRepository;

@Inject
private TagRepository tagRepository;

/**
 * Save a goal.
 *
 * @param goalDTO the entity to save
 * @return the persisted entity
 */
  public GoalDTO save(GoalDTO goalDTO) {
    log.debug("Request to save Goal : {}", goalDTO);
    Goal goal = goalMapper.goalDTOToGoal(goalDTO);
    goal = goalRepository.save(goal);
    GoalDTO result = goalMapper.goalToGoalDTO(goal);
    //goalSearchRepository.save(goal);
    return result;
}

}请帮帮我。

Answer 1

当您尝试使用save时，持久性提供程序尝试级联的操作是PERSIST。当您尝试保留一个已存在的分离实体时，您最终会遇到该异常。

由于您在该关系上设置了 MERGE 级联选项，因此我建议使用合并而不是持久:

goal = goalRepository.merge(goal);

现在，如果您的目标是一个新实体，它将被持久化，并且分离的标签实体将被合并(如果持久化提供程序发现状态发生变化，则会更新)。