POST / PUT期间将所有对象作为其ID的单个自定义反序列化器或嵌入的整个对象

Question

@Entity
public Product {
@Id
public int id;

   public String name;

   @ManyToOne(cascade = {CascadeType.DETACH} )
   Category category

   @ManyToMany(fetch = FetchType.EAGER, cascade = {CascadeType.DETACH} )
   Set<Category> secondaryCategories;


}

和这个实体：

@Entity
public Category {
   @Id
   public int id;

   public String name;
}

我希望能够使用JSON发送POST

{ name: "name", category: 2, secondaryCategories: [3,4,5] } 从客户端

并可以像这样反序列化：

{ name: "name", category: {id: 2 }, secondaryCategories: [{id: 3}, {id: 4}, {id: 5}] }

如果它被发送为

 { name: "name", category: {id: 2 }, secondaryCategories: [{id: 3}, {id: 4}, {id: 5}] }

我希望它能像现在一样工作

我需要什么样的注释和自定义反序列化器？希望反序列化程序可以对以id为属性的所有可能对象起作用

谢谢！

Answer 1

@JsonCreator如果您可以修改实体，则另一种方法是使用工厂方法

private class Product {
    @JsonProperty("category")
    private Category category;

    @JsonProperty("secondaryCategories")
    private List<Category> secondaryCategories;
}


private class Category {
    @JsonProperty("id")
    private int id;

    @JsonCreator
    public static Category factory(int id){
        Category p = new Category();
        p.id = id;
        // or some db call 
        return p;
    }
}

甚至像这样的事情也应该起作用

private class Category {
    private int id;

    public Category() {}

    @JsonCreator
    public Category(int id) {
        this.id = id;
    }
}