Retrofit2极简单使用（入门）

程序员文章站 2024-02-29 23:48:40

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android的网络请求框架不少，如HttpUrlConnection、HttpClient、AsyncHttpClient、Volley、okHttp和Retrofit等等。

今天就说一下Retrofit的简单使用，其实Retrofit的底层也是使用okHttp的，就是把okHttp封装的一下，具体的的请求还是

交给okHttp来执行.

不多说了，下面就说一下具体的使用

使用之前肯定要加载依赖库

compile 'com.squareup.retrofit2:retrofit:2.1.0'

之后开始具体代码

这次demo的请求数据用天气预报的数据https://www.sojson.com/open/api/weather/json.shtml?city=北京

开始写之前记得把网络权限打开

新建activity：RetrofitTestActivity

public class RetrofitTestActivity extends AppCompatActivity {

    private Button btn;
    private EditText editText;
    private TextView textView;
    //必须以 /（斜线） 结束，不然会抛出一个IllegalArgumentException异常
    private  String url="https://www.sojson.com/open/api/weather/";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_retrofit_test);

        btn =(Button) findViewById(R.id.btn);
        editText = (EditText) findViewById(R.id.editR);
        textView = (TextView) findViewById(R.id.text);

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String city = editText.getText().toString();
                //创建Retrofit对象 设定网络请求的路径
                //GsonConverterFactory  是Retrofit解析成Gson格式
                Retrofit retrofit = new  Retrofit.Builder().baseUrl(url).addConverterFactory(GsonConverterFactory.create()).build();
                //获取请求对象
                RetrofitTestIm retrofitTestIm = retrofit.create(RetrofitTestIm.class);
                //获取请求的方法 city为参数
                Call<WeatherBen> call = retrofitTestIm.getweather(city);
                //开始请求可以是同步 也可以是异步
                call.enqueue(new Callback<WeatherBen>() {
                    @Override
                    public void onResponse(Call<WeatherBen> call, Response<WeatherBen> response) {
                        //获得数据
                      WeatherBen.DataEntity.ForecastEntity list = response.body().getData().getForecast().get(0);
                        String wearther = "date:"+list.getDate()+
                                "\n sunrise:"+list.getSunrise()+
                                "\n high:"+list.getHigh()+
                                "\n low:"+list.getLow()+
                                "\n sunset:"+list.getSunset()+
                                "\n aqi:"+list.getAqi()+
                                "\n fx:"+list.getFx()+
                                "\n fl:"+list.getFl()+
                                "\n type:"+list.getType()+
                                "\n notice:"+list.getNotice();
                        textView.setText(wearther);
                    }
                    @Override
                    public void onFailure(Call<WeatherBen> call, Throwable t) {
                    //获取失败
                    }
                });
            }
        });
    }
}

在此之前需建立请求对象，其实Retrofit就是创建一个java接口来描述http请求

接口RetrofitTestIm:

public interface RetrofitTestIm {

    @GET("json.shtml")
    Call<WeatherBen> getweather(@Query("city") String city);
}

http的请求方法有很多种：GET、POST、PUT、DELETE、PATCH、HEAD、OPTIONS和HTTP，但是HTTP可以替换前7个。

实体类WeatherBen用于存放获取的数据

手写闲麻烦的话，可以下载一个自动生成实体类插件GsonFormat,

如何使用：android studio如何使用安转使用GsonFormat

public class WeatherBen {


    /**
     * date : 20180425
     * data : {"shidu":"41%","yesterday":{"date":"24日星期二","sunrise":"05:26","high":"高温 23.0℃","fx":"北风","low":"低温 10.0℃","fl":"3-4级","sunset":"19:01","aqi":38,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},"pm25":23,"pm10":55,"ganmao":"极少数敏感人群应减少户外活动","forecast":[{"date":"25日星期三","sunrise":"05:25","high":"高温 25.0℃","fx":"西南风","low":"低温 11.0℃","fl":"3-4级","sunset":"19:02","aqi":63,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"26日星期四","sunrise":"05:23","high":"高温 26.0℃","fx":"西南风","low":"低温 13.0℃","fl":"<3级","sunset":"19:03","aqi":69,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"27日星期五","sunrise":"05:22","high":"高温 25.0℃","fx":"西南风","low":"低温 14.0℃","fl":"<3级","sunset":"19:04","aqi":64,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"28日星期六","sunrise":"05:21","high":"高温 27.0℃","fx":"西南风","low":"低温 17.0℃","fl":"3-4级","sunset":"19:05","aqi":85,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"29日星期日","sunrise":"05:19","high":"高温 28.0℃","fx":"东南风","low":"低温 16.0℃","fl":"<3级","sunset":"19:06","aqi":96,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"}],"wendu":"16","quality":"良"}
     * city : 北京
     * count : 1000
     * message : Success !
     * status : 200
     */
    private String date;
    private DataEntity data;
    private String city;
    private int count;
    private String message;
    private int status;

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

    public void setData(DataEntity data) {
        this.data = data;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public void setStatus(int status) {
        this.status = status;
    }

    public String getDate() {
        return date;
    }

    public DataEntity getData() {
        return data;
    }

    public String getCity() {
        return city;
    }

    public int getCount() {
        return count;
    }

    public String getMessage() {
        return message;
    }

    public int getStatus() {
        return status;
    }

    public static class DataEntity {
        /**
         * shidu : 41%
         * yesterday : {"date":"24日星期二","sunrise":"05:26","high":"高温 23.0℃","fx":"北风","low":"低温 10.0℃","fl":"3-4级","sunset":"19:01","aqi":38,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"}
         * pm25 : 23.0
         * pm10 : 55.0
         * ganmao : 极少数敏感人群应减少户外活动
         * forecast : [{"date":"25日星期三","sunrise":"05:25","high":"高温 25.0℃","fx":"西南风","low":"低温 11.0℃","fl":"3-4级","sunset":"19:02","aqi":63,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"26日星期四","sunrise":"05:23","high":"高温 26.0℃","fx":"西南风","low":"低温 13.0℃","fl":"<3级","sunset":"19:03","aqi":69,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"},{"date":"27日星期五","sunrise":"05:22","high":"高温 25.0℃","fx":"西南风","low":"低温 14.0℃","fl":"<3级","sunset":"19:04","aqi":64,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"28日星期六","sunrise":"05:21","high":"高温 27.0℃","fx":"西南风","low":"低温 17.0℃","fl":"3-4级","sunset":"19:05","aqi":85,"type":"晴","notice":"愿你拥有比阳光明媚的心情"},{"date":"29日星期日","sunrise":"05:19","high":"高温 28.0℃","fx":"东南风","low":"低温 16.0℃","fl":"<3级","sunset":"19:06","aqi":96,"type":"多云","notice":"阴晴之间，谨防紫外线侵扰"}]
         * wendu : 16
         * quality : 良
         */
        private String shidu;
        private YesterdayEntity yesterday;
        private double pm25;
        private double pm10;
        private String ganmao;
        private List<ForecastEntity> forecast;
        private String wendu;
        private String quality;

        public void setShidu(String shidu) {
            this.shidu = shidu;
        }

        public void setYesterday(YesterdayEntity yesterday) {
            this.yesterday = yesterday;
        }

        public void setPm25(double pm25) {
            this.pm25 = pm25;
        }

        public void setPm10(double pm10) {
            this.pm10 = pm10;
        }

        public void setGanmao(String ganmao) {
            this.ganmao = ganmao;
        }

        public void setForecast(List<ForecastEntity> forecast) {
            this.forecast = forecast;
        }

        public void setWendu(String wendu) {
            this.wendu = wendu;
        }

        public void setQuality(String quality) {
            this.quality = quality;
        }

        public String getShidu() {
            return shidu;
        }

        public YesterdayEntity getYesterday() {
            return yesterday;
        }

        public double getPm25() {
            return pm25;
        }

        public double getPm10() {
            return pm10;
        }

        public String getGanmao() {
            return ganmao;
        }

        public List<ForecastEntity> getForecast() {
            return forecast;
        }

        public String getWendu() {
            return wendu;
        }

        public String getQuality() {
            return quality;
        }

        public static class YesterdayEntity {
            /**
             * date : 24日星期二
             * sunrise : 05:26
             * high : 高温 23.0℃
             * fx : 北风
             * low : 低温 10.0℃
             * fl : 3-4级
             * sunset : 19:01
             * aqi : 38.0
             * type : 多云
             * notice : 阴晴之间，谨防紫外线侵扰
             */
            private String date;
            private String sunrise;
            private String high;
            private String fx;
            private String low;
            private String fl;
            private String sunset;
            private double aqi;
            private String type;
            private String notice;

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

            public void setSunrise(String sunrise) {
                this.sunrise = sunrise;
            }

            public void setHigh(String high) {
                this.high = high;
            }

            public void setFx(String fx) {
                this.fx = fx;
            }

            public void setLow(String low) {
                this.low = low;
            }

            public void setFl(String fl) {
                this.fl = fl;
            }

            public void setSunset(String sunset) {
                this.sunset = sunset;
            }

            public void setAqi(double aqi) {
                this.aqi = aqi;
            }

            public void setType(String type) {
                this.type = type;
            }

            public void setNotice(String notice) {
                this.notice = notice;
            }

            public String getDate() {
                return date;
            }

            public String getSunrise() {
                return sunrise;
            }

            public String getHigh() {
                return high;
            }

            public String getFx() {
                return fx;
            }

            public String getLow() {
                return low;
            }

            public String getFl() {
                return fl;
            }

            public String getSunset() {
                return sunset;
            }

            public double getAqi() {
                return aqi;
            }

            public String getType() {
                return type;
            }

            public String getNotice() {
                return notice;
            }
        }

        public static class ForecastEntity {
            /**
             * date : 25日星期三
             * sunrise : 05:25
             * high : 高温 25.0℃
             * fx : 西南风
             * low : 低温 11.0℃
             * fl : 3-4级
             * sunset : 19:02
             * aqi : 63.0
             * type : 晴
             * notice : 愿你拥有比阳光明媚的心情
             */
            private String date;
            private String sunrise;
            private String high;
            private String fx;
            private String low;
            private String fl;
            private String sunset;
            private double aqi;
            private String type;
            private String notice;

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

            public void setSunrise(String sunrise) {
                this.sunrise = sunrise;
            }

            public void setHigh(String high) {
                this.high = high;
            }

            public void setFx(String fx) {
                this.fx = fx;
            }

            public void setLow(String low) {
                this.low = low;
            }

            public void setFl(String fl) {
                this.fl = fl;
            }

            public void setSunset(String sunset) {
                this.sunset = sunset;
            }

            public void setAqi(double aqi) {
                this.aqi = aqi;
            }

            public void setType(String type) {
                this.type = type;
            }

            public void setNotice(String notice) {
                this.notice = notice;
            }

            public String getDate() {
                return date;
            }

            public String getSunrise() {
                return sunrise;
            }

            public String getHigh() {
                return high;
            }

            public String getFx() {
                return fx;
            }

            public String getLow() {
                return low;
            }

            public String getFl() {
                return fl;
            }

            public String getSunset() {
                return sunset;
            }

            public double getAqi() {
                return aqi;
            }

            public String getType() {
                return type;
            }

            public String getNotice() {
                return notice;
            }
        }
    }
}

示例结果

Retrofit2极简单使用（入门）

Retrofit2极简单使用（入门）