本文是 Android RxJava2+Retrofit2+OkHttp3 的使用(一) --基础篇 Retrofit2 的使用
本文的目标是用 Retrofit写一个网络请求：
本文以从获取天气预报接口 （具体接口查看上文 免费天气预报接口）为例，讲解 Retrofit2 的使用
废话不多说，开撸
一、添加依赖
在build.gradle文件中添加如下配置
//retrofit2 compile 'com.squareup.retrofit2:retrofit:2.3.0'//导入retrofit compile 'com.squareup.retrofit2:converter-gson:2.3.0'//转换器，请求结果转换成Model
二、创建Bean
根据接口返回的JSon数据，使用GsonFormat插件自动创建 WeatherBean 文件 (GsonFormat插件 的安装方法和其余插件安装方法并无二致)
1）打开链接http://t.weather.sojson.com/api/weather/city/101030100，然后复制返回的json数据
2）新建WeatherBean.java ，然后 Alt + Delete ，选择GsonFormat，将复制到的JSON数据赋值进去，点击 “确定” 生成 即可
这是我自动生成的文件：
package com.jack.basemvp.bean; import java.util.List; /** * 由GsonFormat 生成 */ public class WeatherBean { /** * time : 2019-04-20 19:11:47 * cityInfo : {"city":"天津市","cityId":"101030100","parent":"天津","updateTime":"18:32"} * date : 20190420 * message : Success ! * status : 200 * data : {"shidu":"46%","pm25":49,"pm10":87,"quality":"良","wendu":"14","ganmao":"极少数敏感人群应减少户外活动","yesterday":{"date":"19","sunrise":"05:32","high":"高温 18.0℃","low":"低温 11.0℃","sunset":"18:51","aqi":58,"ymd":"2019-04-19","week":"星期五","fx":"东南风","fl":"3-4级","type":"阴","notice":"不要被阴云遮挡住好心情"},"forecast":[{"date":"20","sunrise":"05:30","high":"高温 16.0℃","low":"低温 10.0℃","sunset":"18:52","aqi":64,"ymd":"2019-04-20","week":"星期六","fx":"东北风","fl":"<3级","type":"小雨","notice":"雨虽小，注意保暖别感冒"},{"date":"21","sunrise":"05:29","high":"高温 20.0℃","low":"低温 12.0℃","sunset":"18:53","aqi":72,"ymd":"2019-04-21","week":"星期日","fx":"东南风","fl":"3-4级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"22","sunrise":"05:27","high":"高温 26.0℃","low":"低温 16.0℃","sunset":"18:54","aqi":89,"ymd":"2019-04-22","week":"星期一","fx":"南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"23","sunrise":"05:26","high":"高温 26.0℃","low":"低温 16.0℃","sunset":"18:55","aqi":91,"ymd":"2019-04-23","week":"星期二","fx":"南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"24","sunrise":"05:25","high":"高温 22.0℃","low":"低温 12.0℃","sunset":"18:56","aqi":66,"ymd":"2019-04-24","week":"星期三","fx":"东风","fl":"4-5级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"25","sunrise":"05:23","high":"高温 19.0℃","low":"低温 12.0℃","sunset":"18:57","aqi":41,"ymd":"2019-04-25","week":"星期四","fx":"东南风","fl":"<3级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"26","sunrise":"05:22","high":"高温 21.0℃","low":"低温 12.0℃","sunset":"18:58","ymd":"2019-04-26","week":"星期五","fx":"东南风","fl":"3-4级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"27","sunrise":"05:21","high":"高温 21.0℃","low":"低温 10.0℃","sunset":"18:59","ymd":"2019-04-27","week":"星期六","fx":"南风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"28","sunrise":"05:19","high":"高温 23.0℃","low":"低温 12.0℃","sunset":"19:00","ymd":"2019-04-28","week":"星期日","fx":"北风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"29","sunrise":"05:18","high":"高温 22.0℃","low":"低温 12.0℃","sunset":"19:01","ymd":"2019-04-29","week":"星期一","fx":"北风","fl":"3-4级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"30","sunrise":"05:17","high":"高温 23.0℃","low":"低温 14.0℃","sunset":"19:02","ymd":"2019-04-30","week":"星期二","fx":"东南风","fl":"3-4级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"01","sunrise":"05:15","high":"高温 24.0℃","low":"低温 16.0℃","sunset":"19:03","ymd":"2019-05-01","week":"星期三","fx":"东南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"02","sunrise":"05:14","high":"高温 25.0℃","low":"低温 15.0℃","sunset":"19:04","ymd":"2019-05-02","week":"星期四","fx":"东南风","fl":"3-4级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"03","sunrise":"05:13","high":"高温 24.0℃","low":"低温 14.0℃","sunset":"19:05","ymd":"2019-05-03","week":"星期五","fx":"西南风","fl":"4-5级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"04","sunrise":"05:12","high":"高温 24.0℃","low":"低温 14.0℃","sunset":"19:06","ymd":"2019-05-04","week":"星期六","fx":"东南风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"}]} */ private String time; private CityInfoBean cityInfo; private String date; private String message; private int status; private DataBean data; public String getTime() { return time; } public void setTime(String time) { this.time = time; } public CityInfoBean getCityInfo() { return cityInfo; } public void setCityInfo(CityInfoBean cityInfo) { this.cityInfo = cityInfo; } public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getMessage() { return message; } public void setMessage(String message) { this.message = message; } public int getStatus() { return status; } public void setStatus(int status) { this.status = status; } public DataBean getData() { return data; } public void setData(DataBean data) { this.data = data; } public static class CityInfoBean { /** * city : 天津市 * cityId : 101030100 * parent : 天津 * updateTime : 18:32 */ private String city; private String cityId; private String parent; private String updateTime; public String getCity() { return city; } public void setCity(String city) { this.city = city; } public String getCityId() { return cityId; } public void setCityId(String cityId) { this.cityId = cityId; } public String getParent() { return parent; } public void setParent(String parent) { this.parent = parent; } public String getUpdateTime() { return updateTime; } public void setUpdateTime(String updateTime) { this.updateTime = updateTime; } } public static class DataBean { /** * shidu : 46% * pm25 : 49.0 * pm10 : 87.0 * quality : 良 * wendu : 14 * ganmao : 极少数敏感人群应减少户外活动 * yesterday : {"date":"19","sunrise":"05:32","high":"高温 18.0℃","low":"低温 11.0℃","sunset":"18:51","aqi":58,"ymd":"2019-04-19","week":"星期五","fx":"东南风","fl":"3-4级","type":"阴","notice":"不要被阴云遮挡住好心情"} * forecast : [{"date":"20","sunrise":"05:30","high":"高温 16.0℃","low":"低温 10.0℃","sunset":"18:52","aqi":64,"ymd":"2019-04-20","week":"星期六","fx":"东北风","fl":"<3级","type":"小雨","notice":"雨虽小，注意保暖别感冒"},{"date":"21","sunrise":"05:29","high":"高温 20.0℃","low":"低温 12.0℃","sunset":"18:53","aqi":72,"ymd":"2019-04-21","week":"星期日","fx":"东南风","fl":"3-4级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"22","sunrise":"05:27","high":"高温 26.0℃","low":"低温 16.0℃","sunset":"18:54","aqi":89,"ymd":"2019-04-22","week":"星期一","fx":"南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"23","sunrise":"05:26","high":"高温 26.0℃","low":"低温 16.0℃","sunset":"18:55","aqi":91,"ymd":"2019-04-23","week":"星期二","fx":"南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"24","sunrise":"05:25","high":"高温 22.0℃","low":"低温 12.0℃","sunset":"18:56","aqi":66,"ymd":"2019-04-24","week":"星期三","fx":"东风","fl":"4-5级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"25","sunrise":"05:23","high":"高温 19.0℃","low":"低温 12.0℃","sunset":"18:57","aqi":41,"ymd":"2019-04-25","week":"星期四","fx":"东南风","fl":"<3级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"26","sunrise":"05:22","high":"高温 21.0℃","low":"低温 12.0℃","sunset":"18:58","ymd":"2019-04-26","week":"星期五","fx":"东南风","fl":"3-4级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"27","sunrise":"05:21","high":"高温 21.0℃","low":"低温 10.0℃","sunset":"18:59","ymd":"2019-04-27","week":"星期六","fx":"南风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"28","sunrise":"05:19","high":"高温 23.0℃","low":"低温 12.0℃","sunset":"19:00","ymd":"2019-04-28","week":"星期日","fx":"北风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"29","sunrise":"05:18","high":"高温 22.0℃","low":"低温 12.0℃","sunset":"19:01","ymd":"2019-04-29","week":"星期一","fx":"北风","fl":"3-4级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"30","sunrise":"05:17","high":"高温 23.0℃","low":"低温 14.0℃","sunset":"19:02","ymd":"2019-04-30","week":"星期二","fx":"东南风","fl":"3-4级","type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"01","sunrise":"05:15","high":"高温 24.0℃","low":"低温 16.0℃","sunset":"19:03","ymd":"2019-05-01","week":"星期三","fx":"东南风","fl":"<3级","type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"02","sunrise":"05:14","high":"高温 25.0℃","low":"低温 15.0℃","sunset":"19:04","ymd":"2019-05-02","week":"星期四","fx":"东南风","fl":"3-4级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"03","sunrise":"05:13","high":"高温 24.0℃","low":"低温 14.0℃","sunset":"19:05","ymd":"2019-05-03","week":"星期五","fx":"西南风","fl":"4-5级","type":"阴","notice":"不要被阴云遮挡住好心情"},{"date":"04","sunrise":"05:12","high":"高温 24.0℃","low":"低温 14.0℃","sunset":"19:06","ymd":"2019-05-04","week":"星期六","fx":"东南风","fl":"<3级","type":"阴","notice":"不要被阴云遮挡住好心情"}] */ private String shidu; private double pm25; private double pm10; private String quality; private String wendu; private String ganmao; private YesterdayBean yesterday; private List<ForecastBean> forecast; public String getShidu() { return shidu; } public void setShidu(String shidu) { this.shidu = shidu; } public double getPm25() { return pm25; } public void setPm25(double pm25) { this.pm25 = pm25; } public double getPm10() { return pm10; } public void setPm10(double pm10) { this.pm10 = pm10; } public String getQuality() { return quality; } public void setQuality(String quality) { this.quality = quality; } public String getWendu() { return wendu; } public void setWendu(String wendu) { this.wendu = wendu; } public String getGanmao() { return ganmao; } public void setGanmao(String ganmao) { this.ganmao = ganmao; } public YesterdayBean getYesterday() { return yesterday; } public void setYesterday(YesterdayBean yesterday) { this.yesterday = yesterday; } public List<ForecastBean> getForecast() { return forecast; } public void setForecast(List<ForecastBean> forecast) { this.forecast = forecast; } public static class YesterdayBean { /** * date : 19 * sunrise : 05:32 * high : 高温 18.0℃ * low : 低温 11.0℃ * sunset : 18:51 * aqi : 58.0 * ymd : 2019-04-19 * week : 星期五 * fx : 东南风 * fl : 3-4级 * type : 阴 * notice : 不要被阴云遮挡住好心情 */ private String date; private String sunrise; private String high; private String low; private String sunset; private double aqi; private String ymd; private String week; private String fx; private String fl; private String type; private String notice; public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getSunrise() { return sunrise; } public void setSunrise(String sunrise) { this.sunrise = sunrise; } public String getHigh() { return high; } public void setHigh(String high) { this.high = high; } public String getLow() { return low; } public void setLow(String low) { this.low = low; } public String getSunset() { return sunset; } public void setSunset(String sunset) { this.sunset = sunset; } public double getAqi() { return aqi; } public void setAqi(double aqi) { this.aqi = aqi; } public String getYmd() { return ymd; } public void setYmd(String ymd) { this.ymd = ymd; } public String getWeek() { return week; } public void setWeek(String week) { this.week = week; } public String getFx() { return fx; } public void setFx(String fx) { this.fx = fx; } public String getFl() { return fl; } public void setFl(String fl) { this.fl = fl; } public String getType() { return type; } public void setType(String type) { this.type = type; } public String getNotice() { return notice; } public void setNotice(String notice) { this.notice = notice; } } public static class ForecastBean { /** * date : 20 * sunrise : 05:30 * high : 高温 16.0℃ * low : 低温 10.0℃ * sunset : 18:52 * aqi : 64.0 * ymd : 2019-04-20 * week : 星期六 * fx : 东北风 * fl : <3级 * type : 小雨 * notice : 雨虽小，注意保暖别感冒 */ private String date; private String sunrise; private String high; private String low; private String sunset; private double aqi; private String ymd; private String week; private String fx; private String fl; private String type; private String notice; public String getDate() { return date; } public void setDate(String date) { this.date = date; } public String getSunrise() { return sunrise; } public void setSunrise(String sunrise) { this.sunrise = sunrise; } public String getHigh() { return high; } public void setHigh(String high) { this.high = high; } public String getLow() { return low; } public void setLow(String low) { this.low = low; } public String getSunset() { return sunset; } public void setSunset(String sunset) { this.sunset = sunset; } public double getAqi() { return aqi; } public void setAqi(double aqi) { this.aqi = aqi; } public String getYmd() { return ymd; } public void setYmd(String ymd) { this.ymd = ymd; } public String getWeek() { return week; } public void setWeek(String week) { this.week = week; } public String getFx() { return fx; } public void setFx(String fx) { this.fx = fx; } public String getFl() { return fl; } public void setFl(String fl) { this.fl = fl; } public String getType() { return type; } public void setType(String type) { this.type = type; } public String getNotice() { return notice; } public void setNotice(String notice) { this.notice = notice; } } } }
三、创建Api接口文件 WeatherApi.java
package com.jack.basemvp.api; import com.jack.basemvp.bean.WeatherBean; import java.util.Map; import io.reactivex.Observable; import retrofit2.Call; import retrofit2.http.GET; import retrofit2.http.Path; import retrofit2.http.QueryMap; public interface WeatherApi { String BASE_URL = "http://t.weather.sojson.com/"; /** * 普通方式 * * @param cityId * @return */ //get 传一个参数 @GET("api/weather/city/{cityId}") Call<WeatherBean> weatherInfo(@Path("cityId") int cityId); //get 传多个参数 用 & 拼接 @GET("api/weather/city/101030100?") Call<WeatherBean> weatherInfo2(@QueryMap Map<String, String> params); }
四、主UI界面中使用
RequestCommonActivity.java
package com.jack.basemvp.activity; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.util.Log; import android.view.View; import android.widget.Button; import android.widget.TextView; import com.jack.basemvp.R; import com.jack.basemvp.api.NewsRxApi; import com.jack.basemvp.bean.WeatherBean; import com.jack.basemvp.api.WeatherApi; import com.jack.basemvp.util.http.RetrofitServiceManager; import java.util.HashMap; import java.util.Map; import java.util.concurrent.TimeUnit; import io.reactivex.Observable; import io.reactivex.Observer; import io.reactivex.android.schedulers.AndroidSchedulers; import io.reactivex.annotations.NonNull; import io.reactivex.disposables.Disposable; import io.reactivex.schedulers.Schedulers; import okhttp3.OkHttpClient; import retrofit2.Call; import retrofit2.Callback; import retrofit2.Response; import retrofit2.Retrofit; import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory; import retrofit2.converter.gson.GsonConverterFactory; public class RequestCommonActivity extends AppCompatActivity implements View.OnClickListener { private TextView tv_result; private Button btn_req1, btn_req2; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_request_common); initView(); } private void initView() { tv_result = (TextView) findViewById(R.id.tv_result); btn_req1 = (Button) findViewById(R.id.btn_req1); btn_req2 = (Button) findViewById(R.id.btn_req2); btn_req1.setOnClickListener(this); btn_req2.setOnClickListener(this); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.btn_req1: requestWeather1(); break; case R.id.btn_req2: requestWeather2(); break; } } //get 请求 传一个参数到url中 private void requestWeather1() { Retrofit retrofit = new Retrofit.Builder() .baseUrl(WeatherApi.BASE_URL) .addConverterFactory(GsonConverterFactory.create()) .build(); WeatherApi api = retrofit.create(WeatherApi.class); int cityId = 101030100; //城市ID api.weatherInfo(cityId).enqueue(new Callback<WeatherBean>() { @Override public void onResponse(Call<WeatherBean> call, Response<WeatherBean> response) { try { //date":"20","sunrise":"05:30","high":"高温 16.0℃","low":"低温 10.0℃", WeatherBean.DataBean.ForecastBean todayBean = response.body().getData().getForecast().get(0); tv_result.setText( "date1:" + todayBean.getDate() + "\n" + "high:" + todayBean.getHigh() + "\n" + "low:" + todayBean.getLow() + "\n" ); } catch (Exception e) { e.printStackTrace(); } } @Override public void onFailure(Call<WeatherBean> call, Throwable t) { } }); } //get 请求 传一个参数到url中 private void requestWeather2() { Retrofit retrofit = new Retrofit.Builder() .baseUrl(WeatherApi.BASE_URL) .addConverterFactory(GsonConverterFactory.create()) .build(); Map<String, String> params = new HashMap<>(); params.put("rand", "1"); params.put("key", "4ea58de8a7573377cec0046f5e2469d5"); retrofit.create(WeatherApi.class).weatherInfo2(params).enqueue(new Callback<WeatherBean>() { @Override public void onResponse(Call<WeatherBean> call, Response<WeatherBean> response) { try { //date":"20","sunrise":"05:30","high":"高温 16.0℃","low":"低温 10.0℃", WeatherBean.DataBean.ForecastBean todayBean = response.body().getData().getForecast().get(0); tv_result.setText( "date2:" + todayBean.getDate() + "\n" + "high:" + todayBean.getHigh() + "\n" + "low:" + todayBean.getLow() + "\n" ); } catch (Exception e) { e.printStackTrace(); } } @Override public void onFailure(Call<WeatherBean> call, Throwable t) { } }); } }
界面布局文件：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context="activity.RequestCommonActivity"> <Button android:id="@+id/btn_req1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="普通请求-接口1" android:textAllCaps="false" /> <Button android:id="@+id/btn_req2" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="普通请求-接口2" android:textAllCaps="false" /> <TextView android:id="@+id/tv_result" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="结果展示" /> </LinearLayout>