【知识技术介绍|Retrofit2和Rxjava2和LiveData的请求整理】Retrofit是Square公司出品的基于OkHttp封装的一套RESTful（目前流行的一套api设计的风格）网络请求框架。它内部使用了大量的设计模式，以达到高度解耦的目的；它可以直接通过注解的方式配置请求；可以使用不同的Http客户端；还可以使用json Converter序列化数据，直接转换成你期望生成的实体bean；它还支持Rxjava和LiveData等等等
Rxjava2和LiveData是利用Retrofit2的使用来返回独立的对象处理
LiveData + ViewModel替代Rxjava2，但缺少一些Rxjava2没有的功能，如Stream，Rxjava2中缺少关于LiveData中
LiveData 算是一个数据持久类
Rxjava2 有链式响应请求的过程
组合方式
1、Retrofit 单独请求
2、Retrofit+RxJava实现网络请求，返回的是Observable
3、Retrofit+LiveData实现网络请求，返回的是LiveData
以上请求加上OkHttpClient，可以进行请求拦截处理和超时等设置（超时时间设置生不生效不好说）
Retrofit的创建方式一样，只是ApiService中接口返回不一样
基本形式
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("http://fanyi.youdao.com/") //设置网络请求的Url地址
.addConverterFactory(GsonConverterFactory.create()) //设置数据解析器
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
.build();
返回形式：
@GET("xxxxx")
Call getDataBeanObservable();
@GET("xxxxx")
LiveData getDataBeanLiveData();
@GET("xxxxx")
Observable getDataBeanObservable();
Retrofit + LiveData
RetrofitManager.get("https://cn.bing.com/")
.create(SplashService.class)
.getBingImgLiveData().observe(this, new Observer() {
@Override
public void onChanged(BingImg bingImg) {
Log.d(TAG, "onChanged: 请求结果："+new Gson().toJson(bingImg));
}
});
Retrofit请求分为同步请求和异步请求
写法《一》：单纯使用Retrofit，不加Rxjava的使用
/**
* 描述：第一步:定义一个接口配置网络请求
*/
public interface WeatherService {
//网络接口的使用为查询天气的接口
//
@GET("weather_mini")
//此处回调返回的可为任意类型Call，再也不用自己去解析json数据啦！！！
Call getMessage(@Query("city") String city);
在需要请求网络的地方直接调用下面的方法即可：
/**
* 单纯使用Retrofit的联网请求
*/
private void doRequestByRetrofit() {
//异步
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(API.BASE_URL)//基础URL 建议以 / 结尾
.addConverterFactory(GsonConverterFactory.create())//设置 Json 转换器
.build();
WeatherService weatherService = retrofit.create(WeatherService .class);
Call call = weatherService.getMessage("北京");
call.enqueue(new Callback() {
@Override
public void onResponse(Call call, Response response) {
//测试数据返回
WeatherEntity weatherEntity = response.body();
Log.e("TAG", "response == " +weatherEntity.getData().getGanmao());
}@Override
public void onFailure(Call call, Throwable t) {
Log.e("TAG", "Throwable : " + t);
}
});
//同步请求
try {
Response response = call.execute();
response.body().show();
} catch (IOException e) {
e.printStackTrace();
}
} 写法《二》 Retrofit + Rxjava
区别：使用Rxjava后，返回的不是Call
public interface RxWeatherService {
@GET("weather_mini")
Observable getMessage(@Query("city") String city);
}
请求联网代码：
private void doRequestByRxRetrofit() {
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(API.BASE_URL)//基础URL 建议以 / 结尾
.addConverterFactory(GsonConverterFactory.create())//设置 Json 转换器
.addCallAdapterFactory(RxJavaCallAdapterFactory.create())//RxJava 适配器
.build();
RxWeatherService rxjavaService = retrofit.create(RxWeatherService .class);
rxjavaService .getMessage("北京")
.subscribeOn(Schedulers.io())//IO线程加载数据
.observeOn(AndroidSchedulers.mainThread())//主线程显示数据
.subscribe(new Subscriber() {
@Override
public void onCompleted() {}@Override
public void onError(Throwable e) {}@Override
public void onNext(WeatherEntity weatherEntity) {
Log.e("TAG", "response == " + weatherEntity.getData().getGanmao());
}
});
}
免费赠送一个WeatherEntity实体类（只给偷懒的小伙伴）：
public class WeatherEntity {
private DataBean data;
private int status;
private String desc;
public DataBean getData() {
return data;
}public void setData(DataBean data) {
this.data = https://www.it610.com/article/data;
}public int getStatus() {
return status;
}public void setStatus(int status) {
this.status = status;
}public String getDesc() {
return desc;
}public void setDesc(String desc) {
this.desc = desc;
}public static class DataBean {
private YesterdayBean yesterday;
private String city;
private String aqi;
private String ganmao;
private String wendu;
private List forecast;
public YesterdayBean getYesterday() {
return yesterday;
}public void setYesterday(YesterdayBean yesterday) {
this.yesterday = yesterday;
}public String getCity() {
return city;
}public void setCity(String city) {
this.city = city;
}public String getAqi() {
return aqi;
}public void setAqi(String aqi) {
this.aqi = aqi;
}public String getGanmao() {
return ganmao;
}public void setGanmao(String ganmao) {
this.ganmao = ganmao;
}public String getWendu() {
return wendu;
}public void setWendu(String wendu) {
this.wendu = wendu;
}public List getForecast() {
return forecast;
}public void setForecast(List forecast) {
this.forecast = forecast;
}public static class YesterdayBean {private String date;
private String high;
private String fx;
private String low;
private String fl;
private String type;
public String getDate() {
return date;
}public void setDate(String date) {
this.date = date;
}public String getHigh() {
return high;
}public void setHigh(String high) {
this.high = high;
}public String getFx() {
return fx;
}public void setFx(String fx) {
this.fx = fx;
}public String getLow() {
return low;
}public void setLow(String low) {
this.low = low;
}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 static class ForecastBean {private String date;
private String high;
private String fengli;
private String low;
private String fengxiang;
private String type;
public String getDate() {
return date;
}public void setDate(String date) {
this.date = date;
}public String getHigh() {
return high;
}public void setHigh(String high) {
this.high = high;
}public String getFengli() {
return fengli;
}public void setFengli(String fengli) {
this.fengli = fengli;
}public String getLow() {
return low;
}public void setLow(String low) {
this.low = low;
}public String getFengxiang() {
return fengxiang;
}public void setFengxiang(String fengxiang) {
this.fengxiang = fengxiang;
}public String getType() {
return type;
}public void setType(String type) {
this.type = type;
}
}
}
}
