解析json时结果错误

Question

I'm new to JSonObject, i need to decode a JSON String like this:

{
  "detected_faces": [
    {
      "BoundingBox": {
        "startX": 9,
        "startY": 0,
        "endX": 1024,
        "endY": 1024,
        "Probability": 98.90444278717041
      },
      "Gender": {
        "Gender": "female",
        "Probability": 73.33024740219116
      },
      "Age": {
        "Age-Range": {
          "Low": 39,
          "High": 53
        }
      }
    }
  ]
}

I created class:

 class BoundingBox{
    public int startX;
    public int startY;
    public int endX;
    public int endY;
    @JsonProperty("Probability")
    public String probability;
}

 class Gender{
    @JsonProperty("Gender") 
    public String gender;
    @JsonProperty("Probability") 
    public double probability;
}

 class AgeRange{
    @JsonProperty("Low") 
    public int low;
    @JsonProperty("High") 
    public int high;
}

 class Age{
    @JsonProperty("Age-Range") 
    public AgeRange ageRange;
}

 class DetectedFace{
    @JsonProperty("BoundingBox") 
    public BoundingBox boundingBox;
    @JsonProperty("Gender") 
    public Gender gender;
    @JsonProperty("Age") 
    public Age age;
}

but if I map to DetectedFace, all field are null.

so I tried with this code:

JsonArray arr = jsonObject.getAsJsonArray("detected_faces");
JsonObject jp = new JsonParser().parse(arr.get(0).toString()).getAsJsonObject();
Gson gs = new Gson();
JsonObject jbb = jp.getAsJsonObject("BoundingBox");
BoundingBox bb = gs.fromJson(jbb,BoundingBox.class);
JsonObject jgn = jp.getAsJsonObject("Gender");
Gender gn = gs.fromJson(jgn,Gender.class);

int fields are correctly filled, doubles result to 0 and strings are null. Can anyone tell me where are my mistakes?

Answer 1

I think you don't need to mix Gson and Jackson to deserialize json. Just choose one of them.

This code uses only Jackson.

ObjectMapper mapper = new ObjectMapper();
OuterObject outerObject = mapper.readValue(text, OuterObject.class);

DetectedFace detectedFace = outerObject.detectedFaces.get(0);
BoundingBox boundingBox = detectedFace.boundingBox;
Gender gender = detectedFace.gender;
Age age = detectedFace.age;

class OuterObject{
    @JsonProperty("detected_faces")
    public List<DetectedFace> detectedFaces;
}

Sample result:

OuterObject(detectedFaces=[DetectedFace(boundingBox=BoundingBox(startX=9,
 startY=0, endX=1024, endY=1024, probability=98.90444278717041), 
gender=Gender(gender=female, probability=73.33024740219116), 
age=Age(ageRange=AgeRange(low=39, high=53)))])

Answer 2

try this,

public static <T> ArrayList<T> getArrayListFromJSON(String dataJSON) {
    TypeToken<ArrayList<T>> token = new TypeToken<ArrayList<T>>() {
    };
    ArrayList<T> dataList = new Gson().fromJson(dataJSON, token.getType());
    Log.d(TAG, "getArrayListFromJSON:  dataList : " + dataList);
    return dataList;
}