Spring Boot @ManyToOne only Id @JsonProperty [英] Spring Boot @ManyToOne only Id @JsonProperty

问题描述

帮我找到 JSON 属性注释，谁让我选择一个实体属性来进行 JSON 序列化.我只需要一个.

help me find JSON property annotation who give me choose an entity property to JSON serialization. I need only one.

我是这样编码的:

@Entity
@Table(name = "pages")
public class Page {
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   @Column(name = "id")
   private Long id;

   @Column(name = "name")
   private String name;

   @JsonIgnoreProperties(value = {"name", "description", "pages"}) // it's working, but I want to simplify, I need only project id property to JSON
   @ManyToOne(fetch = FetchType.EAGER)
   @JoinColumn(name = "project_id")
   private Project project;

   //getters and setters
} 

和项目实体:

@Entity
@Table(name = "projects")
public class Project {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "project_id")
    private Long id;

    @Column(name = "project_name")
    private String name;

    @Column(name = "description")
    private String description;


    @OneToMany(targetEntity = Page.class, mappedBy = "project", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @OrderBy("id")
    private List<Page> pages = new ArrayList<>();
}

JSON 应该是:

   {
        "id": 10,
        "name": "Name",
        "project": {"id":1}
   }

推荐答案

您应该创建一个 DataTransferObject (DTO)，而不是使用过多的注释.

Instead of working with too many annotations you should create a DataTransferObject (DTO) instead.

在 DTO 中，您可以准确定义应该公开哪些信息，并将每个实体对象映射到 DTO.这将返回到前端，而不是实体本身.

Within the DTO you define exactly what information should be exposed and map every entity object to a DTO. This is than returned to the frontend, not the entity itself.

这是关于该主题的一个很好的教程:https://www.baeldung.com/entity-to-and-from-dto-for-a-java-spring-application

Here is a good tutorial on the topic: https://www.baeldung.com/entity-to-and-from-dto-for-a-java-spring-application

这篇关于Spring Boot @ManyToOne only Id @JsonProperty的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！