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Николай Семенов
Asked:2020-04-08 18:13:21 +0000 UTC2020-04-08 18:13:21 +0000 UTC

无法将字符串从 JSON 输出到 TextView

  • 772

我正在尝试制作一个在 TextView 中显示来自 Json 的文本的应用程序。目前我得到以下信息：

import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Query;

public interface ApiService {
    /*
    Retrofit get annotation with our URL
    And our method that will return us the List of ContactList
    */
    @GET("/daily_json.js")
    Call<CurrencyOperations> getData(@Query("ID") String resourceName);
    //getMyJSON();
}

货币操作类：

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class CurrencyOperations {

    @SerializedName("Date")
    @Expose
    private String date;
    @SerializedName("PreviousDate")
    @Expose
    private String previousDate;
    @SerializedName("PreviousURL")
    @Expose
    private String previousURL;
    @SerializedName("Timestamp")
    @Expose
    private String timestamp;
    @SerializedName("Valute")
    @Expose
    private Valute valute;

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getPreviousDate() {
        return previousDate;
    }

    public void setPreviousDate(String previousDate) {
        this.previousDate = previousDate;
    }

    public String getPreviousURL() {
        return previousURL;
    }

    public void setPreviousURL(String previousURL) {
        this.previousURL = previousURL;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }

    public Valute getValute() {
        return valute;
    }

    public void setValute(Valute valute) {
        this.valute = valute;
    }
}

美元类：

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class USD {

    @SerializedName("ID") // это связывает то, что находится в json и мой код (я так думаю)
    @Expose
    private String iD;
    @SerializedName("NumCode")
    @Expose
    private String numCode;
    @SerializedName("CharCode")
    @Expose
    private String charCode;
    @SerializedName("Nominal")
    @Expose
    private int nominal;
    @SerializedName("Name")
    @Expose
    private String name;
    @SerializedName("Value")
    @Expose
    private double value;
    @SerializedName("Previous")
    @Expose
    private double previous;

    public String getID() {
        return iD;
    }

    public void setID(String iD) {
        this.iD = iD;
    }

    public String getNumCode() {
        return numCode;
    }

    public void setNumCode(String numCode) {
        this.numCode = numCode;
    }

    public String getCharCode() {
        return charCode;
    }

    public void setCharCode(String charCode) {
        this.charCode = charCode;
    }

    public int getNominal() {
        return nominal;
    }

    public void setNominal(int nominal) {
        this.nominal = nominal;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getValue() {
        return value;
    }

    public void setValue(double value) {
        this.value = value;
    }

    public double getPrevious() {
        return previous;
    }

    public void setPrevious(double previous) {
        this.previous = previous;
    }

}

价值等级：

import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class Valute {

    @SerializedName("USD")
    @Expose
    private USD uSD;

    public USD getUSD() {
        return uSD;
    }

    public void setUSD(USD uSD) {
        this.uSD = uSD;
    }
}

RetroClient 类：

import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class RetroClient {

    /********
     * URLS
     *******/
    private static final String ROOT_URL = "https://www.cbr-xml-daily.ru/";

    /**
     * Get Retrofit Instance
     */
    private static Retrofit getRetrofitInstance() {
        return new Retrofit.Builder()
                .baseUrl(ROOT_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        // !!!
    }

    /**
     * Get API Service
     *
     * @return API Service
     */
    public static ApiService getApiService() {
        return getRetrofitInstance().create(ApiService.class);
    }
}

MainActivity 类：

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

public class MainActivity extends AppCompatActivity {

    private TextView mTextView;
    private CurrencyOperations operations;
    private ArrayList<CurrencyOperations> mList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Creating an object of our api interface
        ApiService api = RetroClient.getApiService();

        /**
         * Calling JSON
         */
        Call<CurrencyOperations> call = api.getData("bash");

        mTextView = (TextView) findViewById(R.id.text);
       // final CurrencyOperations operations = new CurrencyOperations();
      //  this.operations = new CurrencyOperations();
        final USD usd = new USD();

/*        HashMap<String, Object> hm;
        hm = new HashMap<String, Object>();
        //читаем что в себе хранит параметр balance
        hm.put(NAME, urls.getJSONObject(i).getString("name").toString());*/

        call.enqueue(new Callback<CurrencyOperations>() {
            @Override
            public void onResponse(Call<CurrencyOperations> call, Response<CurrencyOperations> response) {
                mTextView.setText(usd.getID()); // ???
            }

            @Override
            public void onFailure(Call<CurrencyOperations> call, Throwable t) {

            }
        });
    }
}

JSON：

{
    "Date": "2020-04-08T11:30:00+03:00",
    "PreviousDate": "2020-04-07T11:30:00+03:00",
    "PreviousURL": "\/\/www.cbr-xml-daily.ru\/archive\/2020\/04\/07\/daily_json.js",
    "Timestamp": "2020-04-07T23:00:00+03:00",
    "Valute": {
        "AUD": {
            "ID": "R01010",
            "NumCode": "036",
            "CharCode": "AUD",
            "Nominal": 1,
            "Name": "Австралийский доллар",
            "Value": 46.6312,
            "Previous": 46.2341
        },
        "AZN": {
            "ID": "R01020A",
            "NumCode": "944",
            "CharCode": "AZN",
            "Nominal": 1,
            "Name": "Азербайджанский манат",
            "Value": 44.4769,
            "Previous": 45.0383
        },
        "GBP": {
            "ID": "R01035",
            "NumCode": "826",
            "CharCode": "GBP",
            "Nominal": 1,
            "Name": "Фунт стерлингов Соединенного королевства",
            "Value": 93.0662,
            "Previous": 93.9429
        },
        "AMD": {
            "ID": "R01060",
            "NumCode": "051",
            "CharCode": "AMD",
            "Nominal": 100,
            "Name": "Армянских драмов",
            "Value": 15.0534,
            "Previous": 15.2434
        },
        "BYN": {
            "ID": "R01090B",
            "NumCode": "933",
            "CharCode": "BYN",
            "Nominal": 1,
            "Name": "Белорусский рубль",
            "Value": 29.5612,
            "Previous": 29.7155
        },
        "BGN": {
            "ID": "R01100",
            "NumCode": "975",
            "CharCode": "BGN",
            "Nominal": 1,
            "Name": "Болгарский лев",
            "Value": 41.9311,
            "Previous": 42.2257
        },
        "BRL": {
            "ID": "R01115",
            "NumCode": "986",
            "CharCode": "BRL",
            "Nominal": 1,
            "Name": "Бразильский реал",
            "Value": 14.274,
            "Previous": 14.2818
        },
        "HUF": {
            "ID": "R01135",
            "NumCode": "348",
            "CharCode": "HUF",
            "Nominal": 100,
            "Name": "Венгерских форинтов",
            "Value": 22.7589,
            "Previous": 22.7079
        },
        "HKD": {
            "ID": "R01200",
            "NumCode": "344",
            "CharCode": "HKD",
            "Nominal": 10,
            "Name": "Гонконгских долларов",
            "Value": 97.3224,
            "Previous": 98.5482
        },
        "DKK": {
            "ID": "R01215",
            "NumCode": "208",
            "CharCode": "DKK",
            "Nominal": 1,
            "Name": "Датская крона",
            "Value": 10.9849,
            "Previous": 11.0588
        },
        "USD": {
            "ID": "R01235",
            "NumCode": "840",
            "CharCode": "USD",
            "Nominal": 1,
            "Name": "Доллар США",
            "Value": 75.455,
            "Previous": 76.4074
        },
        "EUR": {
            "ID": "R01239",
            "NumCode": "978",
            "CharCode": "EUR",
            "Nominal": 1,
            "Name": "Евро",
            "Value": 82.012,
            "Previous": 82.6346
        },
        "INR": {
            "ID": "R01270",
            "NumCode": "356",
            "CharCode": "INR",
            "Nominal": 100,
            "Name": "Индийских рупий",
            "Value": 99.7673,
            "Previous": 10.0268
        },
        "KZT": {
            "ID": "R01335",
            "NumCode": "398",
            "CharCode": "KZT",
            "Nominal": 100,
            "Name": "Казахстанских тенге",
            "Value": 17.2656,
            "Previous": 17.3999
        },
        "CAD": {
            "ID": "R01350",
            "NumCode": "124",
            "CharCode": "CAD",
            "Nominal": 1,
            "Name": "Канадский доллар",
            "Value": 53.8004,
            "Previous": 54.1244
        },
        "KGS": {
            "ID": "R01370",
            "NumCode": "417",
            "CharCode": "KGS",
            "Nominal": 100,
            "Name": "Киргизских сомов",
            "Value": 88.877,
            "Previous": 89.9985
        },
        "CNY": {
            "ID": "R01375",
            "NumCode": "156",
            "CharCode": "CNY",
            "Nominal": 1,
            "Name": "Китайский юань",
            "Value": 10.696,
            "Previous": 10.7725
        },
        "MDL": {
            "ID": "R01500",
            "NumCode": "498",
            "CharCode": "MDL",
            "Nominal": 10,
            "Name": "Молдавских леев",
            "Value": 40.6218,
            "Previous": 40.9691
        },
        "NOK": {
            "ID": "R01535",
            "NumCode": "578",
            "CharCode": "NOK",
            "Nominal": 10,
            "Name": "Норвежских крон",
            "Value": 73.5924,
            "Previous": 72.5616
        },
        "PLN": {
            "ID": "R01565",
            "NumCode": "985",
            "CharCode": "PLN",
            "Nominal": 1,
            "Name": "Польский злотый",
            "Value": 18.0757,
            "Previous": 18.1099
        },
        "RON": {
            "ID": "R01585F",
            "NumCode": "946",
            "CharCode": "RON",
            "Nominal": 1,
            "Name": "Румынский лей",
            "Value": 16.9787,
            "Previous": 17.0972
        },
        "XDR": {
            "ID": "R01589",
            "NumCode": "960",
            "CharCode": "XDR",
            "Nominal": 1,
            "Name": "СДР (специальные права заимствования)",
            "Value": 102.4845,
            "Previous": 103.7895
        },
        "SGD": {
            "ID": "R01625",
            "NumCode": "702",
            "CharCode": "SGD",
            "Nominal": 1,
            "Name": "Сингапурский доллар",
            "Value": 52.9212,
            "Previous": 53.2604
        },
        "TJS": {
            "ID": "R01670",
            "NumCode": "972",
            "CharCode": "TJS",
            "Nominal": 10,
            "Name": "Таджикских сомони",
            "Value": 73.903,
            "Previous": 74.8358
        },
        "TRY": {
            "ID": "R01700J",
            "NumCode": "949",
            "CharCode": "TRY",
            "Nominal": 1,
            "Name": "Турецкая лира",
            "Value": 11.2234,
            "Previous": 11.2795
        },
        "TMT": {
            "ID": "R01710A",
            "NumCode": "934",
            "CharCode": "TMT",
            "Nominal": 1,
            "Name": "Новый туркменский манат",
            "Value": 21.5894,
            "Previous": 21.8619
        },
        "UZS": {
            "ID": "R01717",
            "NumCode": "860",
            "CharCode": "UZS",
            "Nominal": 10000,
            "Name": "Узбекских сумов",
            "Value": 78.0865,
            "Previous": 79.4999
        },
        "UAH": {
            "ID": "R01720",
            "NumCode": "980",
            "CharCode": "UAH",
            "Nominal": 10,
            "Name": "Украинских гривен",
            "Value": 27.8478,
            "Previous": 28.0394
        },
        "CZK": {
            "ID": "R01760",
            "NumCode": "203",
            "CharCode": "CZK",
            "Nominal": 10,
            "Name": "Чешских крон",
            "Value": 30.039,
            "Previous": 29.8461
        },
        "SEK": {
            "ID": "R01770",
            "NumCode": "752",
            "CharCode": "SEK",
            "Nominal": 10,
            "Name": "Шведских крон",
            "Value": 75.4437,
            "Previous": 75.2515
        },
        "CHF": {
            "ID": "R01775",
            "NumCode": "756",
            "CharCode": "CHF",
            "Nominal": 1,
            "Name": "Швейцарский франк",
            "Value": 77.5408,
            "Previous": 78.1901
        },
        "ZAR": {
            "ID": "R01810",
            "NumCode": "710",
            "CharCode": "ZAR",
            "Nominal": 10,
            "Name": "Южноафриканских рэндов",
            "Value": 41.194,
            "Previous": 40.0399
        },
        "KRW": {
            "ID": "R01815",
            "NumCode": "410",
            "CharCode": "KRW",
            "Nominal": 1000,
            "Name": "Вон Республики Корея",
            "Value": 62.1042,
            "Previous": 62.1658
        },
        "JPY": {
            "ID": "R01820",
            "NumCode": "392",
            "CharCode": "JPY",
            "Nominal": 100,
            "Name": "Японских иен",
            "Value": 69.3106,
            "Previous": 70.0247
        }
    }
}

json 链接：https ://www.cbr-xml-daily.ru/daily_json.js

这个项目在 GitHub 上：https ://github.com/Nikolui333/JSONTestL

由于某种原因，我无法在 textView 中显示美元 ID 数据。PS我知道，很可能，我犯的错误很明显，但我以前从未这样做过，所以我不知道如何使代码工作。

java

1 个回答

  1. Best Answer

    直到您联系的那一刻，一切都为您完美运行textView

    您的代码如下所示：

    final USD usd = new USD();

....

call.enqueue(new Callback<CurrencyOperations>() {
    @Override
    public void onResponse(Call<CurrencyOperations> call, Response<CurrencyOperations> response) {
        mTextView.setText(usd.getID()); // ???
    }

    @Override
    public void onFailure(Call<CurrencyOperations> call, Throwable t) {

    }
});

    Как видно, Вы используете для задания текста textView не результат выполнения запроса, а собственноручно созданный пустой объект final USD usd = new USD();.

    Всё, что нужно для исправления проблемы - правильно инициализировать usd:

    call.enqueue(new Callback<CurrencyOperations>() {
    @Override
    public void onResponse(Call<CurrencyOperations> call, Response<CurrencyOperations> response) {
        USD usd = response.body().getValute().getUSD();
        mTextView.setText(usd.getID());
    }

    @Override
    public void onFailure(Call<CurrencyOperations> call, Throwable t) {

    }
});

    Добавлю, что в целом Вы немного неправильно работаете с POJO классами для данного json, но это не критично. Просто не все данные получаете оттуда. И я бы рекомендовал перейти на Kotlin. Создавать там data классы вместо POJO - одно удовольствие)

    • 2

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