java - Jackson 多态类型处理 - 属性被丢弃

Question

我有这个 JSON 模型类，

public class Response {

    @JsonTypeInfo(use= JsonTypeInfo.Id.NAME, include=JsonTypeInfo.As.PROPERTY, property="category")
    @JsonSubTypes({
            @Type(value = Series.class, name = "Series"),
            @Type(value = Movies.class, name = "Movies")})
    public static abstract class Asset {
        public String category;
        public String id;
    }

    public static class Series extends Asset {
        public String seriesName;
        public int seasonNumber;
    }

    public static class Movies extends Asset {
        public String movieName;
    }

    public Asset[] assets;
}

当我尝试反序列化以下 JSON 时，

{
    assets: [
        {
            "category": "Series",
            "id": "ID1",
            "seriesName": "SeriesName1",
            "seasonNumber": 1
        },
        {
            "category": "Movies",
            "id": "ID2",
            "movieName": "MovieName1"
        }
    ]
}

我看到所有属性都正确反序列化，除了 category 属性，它在两种 Assets 类型中都是 null。

我做错了什么吗？或者这是预期的行为 - 用于推断子类型的属性在反序列化期间被丢弃？

Answer 1

你需要设置visible = true:

@JsonTypeInfo(
    use= JsonTypeInfo.Id.NAME,
    include=JsonTypeInfo.As.PROPERTY,
    property="category",
    visible = true
)