JSON解析Android Java

Question

我想解析这个json但我无法做到这一点。 继承人的Json结构：

例如：我想获取String产品类型=> Car

此代码不起作用：

JSONObject mainData = response.getJSONObject("decode");
String productType = mainData.getString("Product Type");

请帮忙

Answer 1

decode是一个数组而不是对象，所以应该是

JSONArray mainData = response.getJSONArray("decode");

然后，您可以使用索引获取内部对象。

JSONObject jsonObj = mainData.getJSONObject(0);
String answer = jsonObj.getString("label"); //Make

Answer 2

您可以尝试使用Gson

用这样的东西定义你的班级

public class YourClass implements Parcelable {

    private int price;

    @SerializedName("price_currency")
    private String priceCurrency;

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public String getPriceCurrency() {
        return priceCurrency;
    }

    public void setPriceCurrency(String priceCurrency) {
        this.priceCurrency = priceCurrency;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        super.writeToParcel(dest, flags);
        dest.writeInt(this.price);
        dest.writeString(this.priceCurrency);
    }

    public YourClass() {
    }

    protected YourClass(Parcel in) {
        super(in);
        this.price = in.readInt();
        this.priceCurrency = in.readString();
    }

    public static final Creator<YourClass> CREATOR = new Creator<YourClass>() {
        @Override
        public Pessoa createFromParcel(Parcel source) {
            return new YourClass(source);
        }

        @Override
        public YourClass[] newArray(int size) {
            return new YourClass[size];
        }
    };
}

并尝试用这样的东西转换你的json

Gson gson = new Gson();

YourClass yourClass = gson.fromJson(yourJson, YourClass.class);

Answer 3

如果您确实想正确执行此操作，则需要一个自定义JsonDeserializer 。 像这样：

public class CarDeserializer implements JsonDeserializer<Car> {
    @Override
    public Car deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {

        Car car = new Gson().fromJson(json.toString(), Car.class);

        try {
            JSONObject object = new JSONObject(json.toString());

            car.setCurrency(Currency.getInstance(object.getString("price_currency")));
            car.setBalance(object.getJSONObject("balance").getInt("API Decode"));

            JSONArray decodeArray = object.getJSONArray("decode");

            for (int i = 0; i < decodeArray.length(); i++){
                JSONObject decodeObject = (JSONObject) decodeArray.get(i);

                if (decodeObject.get("label").equals("Make")){
                    car.setMake(decodeObject.getString("value"));
                } else if (decodeObject.get("label").equals("Manufacturer")){
                    car.setManufacturer(decodeObject.getString("value"));
                } else if (decodeObject.get("label").equals("Plant Country")){
                    car.setPlantCountry(decodeObject.getString("value"));
                } else if (decodeObject.get("label").equals("Product Type")){
                    car.setProductType(decodeObject.getString("value"));
                }
            }

        } catch (JSONException e){
            Log.e("CarDeserializer", e.toString(), e);
        }

        return car;
    }
}

Car对象如下所示：

public class Car {
    private int price;

    private transient Currency currency;
    private transient int balance;

    private transient String make;
    private transient String manufacturer;
    private transient String plantCountry;
    private transient String productType;

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public Currency getCurrency() {
        return currency;
    }

    public void setCurrency(Currency currency) {
        this.currency = currency;
    }

    public int getBalance() {
        return balance;
    }

    public void setBalance(int balance) {
        this.balance = balance;
    }

    public String getMake() {
        return make;
    }

    public void setMake(String make) {
        this.make = make;
    }

    public String getManufacturer() {
        return manufacturer;
    }

    public void setManufacturer(String manufacturer) {
        this.manufacturer = manufacturer;
    }

    public String getPlantCountry() {
        return plantCountry;
    }

    public void setPlantCountry(String plantCountry) {
        this.plantCountry = plantCountry;
    }

    public String getProductType() {
        return productType;
    }

    public void setProductType(String productType) {
        this.productType = productType;
    }
}

如果Currency不适用于您，则可以将其更改为类似于以下的String类型：

@SerializedName("price_currency") private String currency;

并相应地更改getter和setter 。

如果decode数组中有更多对象。 您可以将它们添加为反序列化器中的更多分支。

这样使用：

GsonBuilder gsonBuilder = new GsonBuilder();
gsonBuilder.registerTypeAdapter(Car.class, new CarDeserializer());

Gson gson = gsonBuilder.create();

gson.fromJson(myJsonString, Car.class);

注意： Car类中的transient关键字向Gson指示，它不应尝试自动解析这些字段的json。

注意2：如果尚未添加Gson，则需要在项目中包括它。