Parse data from OpenWeatherMap, using retrofit2 and rxJava2

问题

I've started to learn Retrofit and RxJava, and I've decided to create weatherApp. Now my goal is to retrieve weather data from OpenWeatherMap Api. Here's my code: For api:

package com.example.aldres.workingwithapis.Api;

import com.example.aldres.workingwithapis.models.WeatherData;

import retrofit2.http.GET;
import retrofit2.http.Query;
import rx.Observable;

public interface Api {
    @GET("weather?")
    Observable<WeatherData> getWeatherData(@Query("q") String city);
}

Also code for my WeatherData model:

package com.example.aldres.workingwithapis.models;

import java.util.List;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;

public class WeatherData {

    @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;
    }

}

And also my mainActivity:

package com.example.aldres.workingwithapis;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import com.example.aldres.workingwithapis.Api.Api;
import com.example.aldres.workingwithapis.models.WeatherData;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;
import rx.Observable;
import rx.Subscriber;
import rx.android.schedulers.AndroidSchedulers;
import rx.schedulers.Schedulers;

public class MainActivity extends AppCompatActivity {
    private TextView middleText;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        middleText = findViewById(R.id.middleText);

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

        Observable<WeatherData> observable = apiService.getWeatherData("London");

                observable
                .subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Subscriber<WeatherData>() {
                    @Override
                    public void onCompleted() {

                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onNext(WeatherData weatherData) {
                        middleText.setText(weatherData.getWind());
                    }
                });
    }
}

At this point, my app should display string with wind parameter into my TextView middleText, but when I start my app, it starts without any errors, but I don't have my text in the TextView. What have I done wrong?

回答1:

Your request is probably erroring out without you knowing about it as you ignore the onError method. Add e.printStackTrace() to that method to see if this is the case.

来源：https://stackoverflow.com/questions/47303003/parse-data-from-openweathermap-using-retrofit2-and-rxjava2