如何處理 JSON 數組與響應是兩個對象的孩子，但不同的內容

Question

大家晚安，嗨，我的基於 reddit API 的應用程序有一個問題，我在其中調用帖子詳細信息路由，響應是一組數據對象，但主要孩子指的是帖子。 第二個是您的評論。

完整的回應：

[
{
    "kind": "Listing",
    "data": {
        "modhash": "",
        "dist": 1,
        "children": [],
        "after": null,
        "before": null
    }
},
{
    "kind": "Listing",
    "data": {
        "modhash": "",
        "dist": null,
        "children": [],
        "after": null,
        "before": null
    }   
}
]

第一個孩子是基於帖子的數組數據，第二個孩子是基於帖子評論的數組數據。 兩者都有不同的領域，也就是說，在第一個孩子中，它沒有第二個孩子的所有領域，例如

處理這種結果的最佳方法是什么，無論是在 kotlin 還是 java 中？

url 示例https://www.reddit.com/r/funny/comments/mei33b/updated_my_wall_art_to_be_more_relevant.Z466DEEC76ECDF5FCA6D345

Answer 1

你不能只是反序列化它，下面似乎工作正常（我沒有費心添加所有字段）？

public static void main(String[] args) {
    ObjectMapper mapper = new ObjectMapper();
    try (FileInputStream fs = new FileInputStream("reddit.json")) {
        Reddit[] reddit = mapper.readValue(fs, Reddit[].class);
        System.out.println(reddit[0].kind);
        System.out.println(reddit[0].data.children[0].data.thumbnail);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

public static class Reddit {

    public final String kind;
    public final Data data;

    @JsonCreator
    public Reddit(
        @JsonProperty("kind") String kind,
        @JsonProperty("data") Data data
    ) {
        this.kind = kind;
        this.data = data;
    }
}

@JsonIgnoreProperties(ignoreUnknown = true)
public static class Data {

    public final String modhash;
    public final Integer dist;
    public final ChildData[] children;
    public final String after;
    public final String before;

    @JsonCreator
    public Data(
        @JsonProperty("modhash") String modhash,
        @JsonProperty("dist") Integer dist,
        @JsonProperty("children") ChildData[] children,
        @JsonProperty("after") String after,
        @JsonProperty("before") String before
    ) {
        this.modhash = modhash;
        this.dist = dist;
        this.children = children;
        this.after = after;
        this.before = before;
    }
}

public static class ChildData {

    public final String kind;
    public final ChildDataData data;

    @JsonCreator
    public ChildData(
        @JsonProperty("kind") String kind,
        @JsonProperty("data") ChildDataData data
    ) {
        this.kind = kind;
        this.data = data;
    }
}

@JsonIgnoreProperties(ignoreUnknown = true)
public static class ChildDataData {

    public final Integer total_awards_received;
    public final String body;
    public final String thumbnail;

    @JsonCreator
    public ChildDataData(
        @JsonProperty("total_awards_received") Integer total_awards_received,
        @JsonProperty("body") String body,
        @JsonProperty("thumbnail") String thumbnail
    ) {
        this.total_awards_received = total_awards_received;
        this.body = body;
        this.thumbnail = thumbnail;
    }
}

類似的事情，您可能想將名稱更改為對您有意義的名稱，並且您需要將所有字段添加到 ChildDataData 但我認為您明白了嗎？

Gradle 依賴項

dependencies {
    implementation group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.12.2'
    implementation group: 'com.fasterxml.jackson.core', name: 'jackson-annotations', version: '2.12.2'
}