我正在使用 REST Web 服务。我正在尝试从数据库中获取一个实体,但我的方法返回许多相同的记录。我正在使用 EclipseLink JPA 实现。
这是我的实体:
@Entity
@Table(name = "News")
public final class News implements Serializable, IEntity {
/**
* For deserialization with no exception after modification.
*/
private static final long serialVersionUID = 3773281197317274020L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "news_id", precision = 0)
private Long newsId; // Primary key
@Column(name = "title")
private String title;
@Column(name = "short_text")
private String shortText;
@Column(name = "full_text")
private String fullText;
@Temporal(TemporalType.DATE)
@Column(name = "creation_date")
private Date creationDate;
@Temporal(TemporalType.DATE)
@Column(name = "modification_date")
private Date modificationDate;
@OneToMany(fetch = FetchType.EAGER, mappedBy = "news")
private List<Comment> commentsList;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(name = "news_tag", joinColumns = { @JoinColumn(name = "news_id") }, inverseJoinColumns = { @JoinColumn(name = "tag_id") })
private Set<Tag> tagSet;
@ManyToOne(fetch = FetchType.EAGER)
@JoinTable(name = "news_author", joinColumns = { @JoinColumn(name = "news_id") }, inverseJoinColumns = { @JoinColumn(name = "author_id") })
private Author author;
我的 Controller 方法:
@RequestMapping(value = { "/singleNews/{newsId}" }, method = RequestMethod.GET)
public @ResponseBody News showSingleNews(@PathVariable("newsId") Long newsId) throws ServiceException {
News news = newsService.getSingleNewsById(newsId);
news.setCommentsList(commentService.getListOfCommentsByNewsId(newsId));
return news;
}
最佳答案
尝试对类(class)中的每个列表使用惰性获取类型
@OneToMany(fetch = FetchType.LAZY)
关于java - REST Web 服务以 JSON 格式返回多个实体,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/33893017/