java - openweathermap API 有方括号中的部分，无法在 Android Studio 中调用该 json 数据

Question

所以我正在尝试制作一个天气应用程序，API 可以工作，但仅在某些区域有效。现在，我只是尝试对 API 进行 Toast，以确保它可以正常工作，然后再继续执行应用程序的其余部分。

public class MainActivity extends AppCompatActivity
{

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


        // Retrofit
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://api.openweathermap.org/data/2.5/")
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        OpenWeatherMapClient api = retrofit.create(OpenWeatherMapClient.class);
        Call<DailyWeather> call = api.getDailyWeather();
        call.enqueue(new Callback<DailyWeather>()
        {
        @Override
        public void onResponse(Call<DailyWeather> call, Response<DailyWeather> response)
            {
                Toast.makeText(MainActivity.this, (response.body().getWeather().getDescription()).toString(), Toast.LENGTH_SHORT).show();
                for( Weather w : response.body().getWeather())


                {
                    Log.d("Weather", w.getId().toString());
                    Log.d("Weather", w.getMain().toString());
                    Log.d("Weather", w.getDescription().toString());
                }

            }

所以这是我的 MainActivity.java，如果我用 .getCoord().getLat()) 替换 getWeather().getDescription()) 就可以了。我唯一注意到的是天气的 API 部分位于方括号中。

因此，如果我运行 API 搜索“Birmingham,uk”，这就是 json(在通过在线解析器以便于阅读之后)

{
"coord":{
"lon":-1.9,
"lat":52.48
},
"weather":[
{
"id":802,
"main":"Clouds",
"description":"scattered clouds",
"icon":"03d"
}
],
"base":"stations",
"main":{
"temp":282.57,
"pressure":1008,
"humidity":76,
"temp_min":282.15,
"temp_max":283.15
},

For reference I'll leave the Coord and Weather classes I have in case the error is in there.

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

public class Coord {

    @SerializedName("lon")
    @Expose
    private Double lon;
    @SerializedName("lat")
    @Expose
    private Double lat;

    public Double getLon() {
        return lon;
    }

    public void setLon(Double lon) {
        this.lon = lon;
    }

    public Double getLat() {
        return lat;
    }

    public void setLat(Double lat) {
        this.lat = lat;
    }

}

还有

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

public class Weather {

    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("main")
    @Expose
    private String main;
    @SerializedName("description")
    @Expose
    private String description;
    @SerializedName("icon")
    @Expose
    private String icon;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getMain() {
        return main;
    }

    public void setMain(String main) {
        this.main = main;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon;
    }

}

以及请求的 DailyWeather 类

 public class DailyWeather {

    @SerializedName("coord")
    @Expose
    private Coord coord;
    @SerializedName("weather")
    @Expose
    private List<Weather> weather = null;
    @SerializedName("base")
    @Expose
    private String base;
    @SerializedName("main")
    @Expose
    private Main main;
    @SerializedName("visibility")
    @Expose
    private Integer visibility;
    @SerializedName("wind")
    @Expose
    private Wind wind;
    @SerializedName("clouds")
    @Expose
    private Clouds clouds;
    @SerializedName("dt")
    @Expose
    private Integer dt;
    @SerializedName("sys")
    @Expose
    private Sys sys;
    @SerializedName("id")
    @Expose
    private Integer id;
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("cod")
    @Expose
    private Integer cod;

    public Coord getCoord() {
        return coord;
    }

    public void setCoord(Coord coord) {
        this.coord = coord;
    }

    public List<Weather> getWeather() {
        return weather;
    }

    public void setWeather(List<Weather> weather) {
        this.weather = weather;
    }

    public String getBase() {
        return base;
    }

    public void setBase(String base) {
        this.base = base;
    }

    public Main getMain() {
        return main;
    }

    public void setMain(Main main) {
        this.main = main;
    }

    public Integer getVisibility() {
        return visibility;
    }

    public void setVisibility(Integer visibility) {
        this.visibility = visibility;
    }

    public Wind getWind() {
        return wind;
    }

    public void setWind(Wind wind) {
        this.wind = wind;
    }

    public Clouds getClouds() {
        return clouds;
    }

    public void setClouds(Clouds clouds) {
        this.clouds = clouds;
    }

    public Integer getDt() {
        return dt;
    }

    public void setDt(Integer dt) {
        this.dt = dt;
    }

    public Sys getSys() {
        return sys;
    }

    public void setSys(Sys sys) {
        this.sys = sys;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public Integer getCod() {
        return cod;
    }

    public void setCod(Integer cod) {
        this.cod = cod;
    }
}

Answer 1

天气变量是一个列表，因此要访问它，您应该执行以下操作:

List<Weather> weatherList = response.body().getWeather();
if(weatherList!=null && !weatherList.isEmpty()){
       Toast.makeText(MainActivity.this, (weatherList.get(0).getDescription()).toString(), Toast.LENGTH_SHORT).show();
}

您无法执行 getWeather().getDescription()，因为 getWeather() 返回一个列表。因此，您需要在列表中选择一个元素，然后才执行 getDescription()。