Android 基于Retrofit+Rxjava搭建的简单易用的网络架构

装逼开始之前，为大家推荐两篇文章，用来更好的学习Retrofit和Rxjava。在这里我们要感谢互联网装逼行业勇于献身，甘于奉献的的大婶们。我仅代表个人，给您们跪舔了。

Retrofit：Retrofit官网

Rxjava：给 Android 开发者的 RxJava 详解

---------------这是分割线---------------

首先配置支持的gradle文件：

    compile 'io.reactivex:rxjava:1.1.3'
    compile 'io.reactivex:rxandroid:1.1.0'
    compile 'com.squareup.retrofit2:retrofit:2.0.1'
    compile 'com.squareup.retrofit2:converter-gson:2.0.1'
    compile 'com.squareup.retrofit2:adapter-rxjava:2.0.1'

截止至本文发表前，上述支持库都是最新版本。

贴出Retrofit官网的GET请求示例：GitHubService接口

public interface GitHubService {
  @GET("users/{user}/repos")
  Call> listRepos(@Path("user") String user);
}

网络请求部分代码为：

        String baseUrl = "https://*******";

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(baseUrl)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        GitHubService service = retrofit.create(GitHubService.class);
        Call> repos = service.listRepos("octocat");
        repos.enqueue(new Callback() {
            @Override
            public void onResponse(Call call, Response response) {
                Log.i("onResponse",response.body().toString());
            }

            @Override
            public void onFailure(Call call, Throwable t) {
                Log.i("onResponse",t.getMessage());
            }
        });

baseUrl 为网络请求地址

addConverterFactory(GsonConverterFactory.create())为设置json解析方式为Gson。

retrofit.create采用动态代理的方式获取GitHubService对象，并通过Callback获取返回的数据。

---------------当Retrofit与Rxjava相遇----------------

Retrofit.Builder需要调用

.addCallAdapterFactory(RxJavaCallAdapterFactory.create())

方法，表示用Rxjava做回调，即Rxjava所讲的观察者模式。那么网络请求接口就需要改成如下方式：

Observable> listRepos(@Path("user") String user);

网络请求部分的代码则更改为：

        String baseUrl = "https://*******";

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(baseUrl)
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        service.listRepos("octocat")
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Subscriber() {
                    @Override
                    public void onCompleted() {
                        Log.i("onCompleted","onCompleted");
                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.i("onError",e.toString());
                    }

                    @Override
                    public void onNext(XXXEntity movieEntity) {
                        Log.i("onCompleted",movieEntity.toString());
                    }
                });

如果仔细阅读过上述两篇文章，不难理解这部分代码的含义，由于篇幅原因，这里就不在重复了。

当然如此这般的结合，无法满足对代码有深度洁癖的骚年们。接下来，在此基础上，对代码做整体的封装。

项目目录结构如下：

首先封装网络请求类HTTPHelper.java

    /**
     * 这一部分配置常量，可以抽取出常量类
     */
    private static final String BASE_PATH = "http://www.weather.com.cn/";//访问的地址
    private static final long DEFAULT_TIMEOUT = 5000;//默认超时时间(毫秒)


    private Retrofit mRetrofit;
    private INetService mNetService;

    private HTTPHelper(){
        OkHttpClient.Builder okHttpClient = new OkHttpClient.Builder();
        okHttpClient.addInterceptor(new HTTPInterceptor());
        okHttpClient.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.MILLISECONDS);
        mRetrofit = new Retrofit.Builder()
                .client(okHttpClient.build())
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .baseUrl(BASE_PATH)
                .build();

        mNetService = mRetrofit.create(INetService.class);

    }

    /**
     * 单例控制器
     */
    private static class SingletonHolder{
        private static final HTTPHelper INSTANCE = new HTTPHelper();
    }

    /**
     * 获取单例对象
     * @return
     */
    public static HTTPHelper getInstance(){
        return SingletonHolder.INSTANCE;
    }

我们需要将网络请求回来的字符串转换成javaBean对象，所以引入Rxjava的map转换机制。代码如下：

    private class HttpResultFunc implements Func1 {
        @Override
        public T call(IModel iModel) {
            if (iModel == null){
                try {
                    throw new Exception("result model is null");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return (T)iModel;
        }
    }

到此，配置阶段结束，下面将是Rxjava的异步订阅请求网络并返回操作。为了方便Activity、Fragment等界面处理数据，封装Subscriber接口：

package demo.myframework.common;

import rx.Subscriber;

/**
 * @Author: lizhipeng
 * @Data: 16/4/12 下午4:17
 * @Description: 自定义调阅者以及结果监听接口
 */
public class ResultSubscriber extends Subscriber {
    private int mRequestType;
    private OnResultListener mListener = null;

    /**
     * 自定义订阅，参数用来区分网络接口，以用来在不同接口操作过程中，处理不同的逻辑
     * @param requestType
     */
    public ResultSubscriber(int requestType) {
        this.mRequestType = requestType;
        mListener = new OnResultListener() {
            @Override
            public void onStart(int requestType) {
            }
            @Override
            public void onCompleted(int requestType) {
            }
            @Override
            public void onError(Throwable e, int requestType) {
            }
            @Override
            public void onNext(T t, int requestType) {
            }
        };
    }

    @Override
    public void onStart() {
        mListener.onStart(mRequestType);
    }

    @Override
    public void onCompleted() {
        mListener.onCompleted(mRequestType);
    }

    @Override
    public void onError(Throwable e) {
        if (e != null){
            mListener.onError(e,mRequestType);
        }
    }

    @Override
    public void onNext(T t) {
        mListener.onNext(t,mRequestType);
    }

    /**
     * 设置订阅监听器
     * @param listener
     */
    public void setOnResultListener(OnResultListener listener){
        if (listener != null){
            mListener = listener;
        }
    }

    /**
     * 订阅的监听器
     * @param 
     */
    public interface OnResultListener {
        /**
         * 网络请求订阅开始
         */
        void onStart(int requestType);
        /**
         * 网络请求完成
         */
        void onCompleted(int requestType);
        /**
         * 网络请求错误
         */
        void onError(Throwable e,int requestType);
        /**
         * 处理请求结果
         */
        void onNext(T t,int requestType);
    }
}

已天气访问为例网络请求接口为：

package demo.myframework.interfaces;

import demo.myframework.model.WeatherModel;
import retrofit2.http.GET;
import retrofit2.http.Path;
import rx.Observable;

/**
 * @Author: lizhipeng
 * @Data: 16/4/12 下午2:57
 * @Description:  网络请求接口
 */
public interface INetService {
    @GET("data/cityinfo/{city_id}.html")
    Observable getWeather(@Path("city_id") String city);
}

HTTPHelper.java 中 网络请求数据方法的实现为：

    /**
     * 获取网络数据的方法
     * @param cityId
     */
    public void getWeather(String cityId, int resultType, ResultSubscriber.OnResultListener listener){
        ResultSubscriber subscriber = new ResultSubscriber<>(resultType);
        subscriber.setOnResultListener(listener);
        mNetService.getWeather(cityId)
                .map(new HttpResultFunc())
                .subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(subscriber);
    }

MainActivity实现OnResultListener接口，点击按钮调用方法为

       HTTPHelper.getInstance().getWeather("101010300",CODE,MainActivity.this);

一下是activity的全部代码：

package demo.myframework.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 demo.myframework.R;
import demo.myframework.common.ResultSubscriber;
import demo.myframework.http.HTTPHelper;
import demo.myframework.model.IModel;
import demo.myframework.model.WeatherModel;

public class MainActivity extends AppCompatActivity implements ResultSubscriber.OnResultListener{
    private static final String TAG = "MainActivity";
    private static final int CODE = 1;

    private Button mButton;
    private TextView mTextView;



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

        initView();
        initData();
    }

    private void initData() {
        mButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.i(TAG,"onClick");
                HTTPHelper.getInstance().getWeather("101010300",CODE,MainActivity.this);
            }
        });
    }

    private void initView() {
        mButton = (Button) findViewById(R.id.button);
        mTextView = (TextView) findViewById(R.id.textview);
    }

    private void setResultSubscriber(){

    }

    /**
     * 网络请求前调用，通常显示Progressialog
     * @param requestType
     */
    @Override
    public void onStart(int requestType) {
        Log.i(TAG,"onStart");
    }

    /**
     * 网络请求完成调用，通常销毁Progressialog
     * @param requestType
     */
    @Override
    public void onCompleted(int requestType) {
        Log.i(TAG,"onCompleted");
    }

    /**
     * 网络请求错误后调用
     * @param e
     * @param requestType
     */
    @Override
    public void onError(Throwable e, int requestType) {
        Log.i(TAG,"onError");
    }

    /**
     * onNext 方法中处理请求下来的数据
     * @param iModel
     * @param requestType
     */
    @Override
    public void onNext(IModel iModel, int requestType) {
        Log.i(TAG,"onNext");
        if (requestType == CODE){
            mTextView.setText(((WeatherModel)iModel).getWeatherinfo().toString());
        }
    }
}

另为了方便测试联调，实现OKhttp的过滤接口。一下代码分别为过滤器和javaBean的实现：

HTTPInterceptor.java

package demo.myframework.http;

import android.util.Log;

import java.io.IOException;

import okhttp3.Interceptor;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

/**
 * @Author: lizhipeng
 * @Data: 16/4/12 下午5:19
 * @Description: 定义http拦截器，用于设置http协议和日志调试
 */
public class HTTPInterceptor implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        //封装headers
        Request request = chain.request().newBuilder()
                .addHeader("Content-Type", "application/json") //添加请求头信息
                .build();
//        Headers headers = request.headers();
        String requestUrl = request.url().toString(); //获取请求url地址
        String methodStr = request.method(); //获取请求方式
        RequestBody body = request.body(); //获取请求body
        String bodyStr = (body==null?"":body.toString());
        //打印Request数据
        Log.i("HTTP-Interceptor","requestUrl=====>"+requestUrl);
        Log.i("HTTP-Interceptor","requestMethod=====>"+methodStr);
        Log.i("HTTP-Interceptor","requestBody=====>"+body);

        Response response = chain.proceed(request);
        return response;
    }
}

WeatherModel.java

package demo.myframework.model;

/**
 * @Author: lizhipeng
 * @Data: 16/4/12 下午3:16
 * @Description:  天气信息模板
 */
public class WeatherModel implements IModel{

    /**
     * city : 朝阳
     * cityid : 101010300
     * temp1 : -2℃
     * temp2 : 16℃
     * weather : 晴
     * img1 : d0.gif
     * img2 : n0.gif
     * ptime : 18:00
     */

    private WeatherinfoBean weatherinfo;

    public WeatherinfoBean getWeatherinfo() {
        return weatherinfo;
    }

    public void setWeatherinfo(WeatherinfoBean weatherinfo) {
        this.weatherinfo = weatherinfo;
    }

    public static class WeatherinfoBean {
        private String city;
        private String cityid;
        private String temp1;
        private String temp2;
        private String weather;
        private String img1;
        private String img2;
        private String ptime;

        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 getTemp1() {
            return temp1;
        }

        public void setTemp1(String temp1) {
            this.temp1 = temp1;
        }

        public String getTemp2() {
            return temp2;
        }

        public void setTemp2(String temp2) {
            this.temp2 = temp2;
        }

        public String getWeather() {
            return weather;
        }

        public void setWeather(String weather) {
            this.weather = weather;
        }

        public String getImg1() {
            return img1;
        }

        public void setImg1(String img1) {
            this.img1 = img1;
        }

        public String getImg2() {
            return img2;
        }

        public void setImg2(String img2) {
            this.img2 = img2;
        }

        public String getPtime() {
            return ptime;
        }

        public void setPtime(String ptime) {
            this.ptime = ptime;
        }

        @Override
        public String toString() {
            return "WeatherinfoBean{" +
                    "city='" + city + '\'' +
                    ", cityid='" + cityid + '\'' +
                    ", temp1='" + temp1 + '\'' +
                    ", temp2='" + temp2 + '\'' +
                    ", weather='" + weather + '\'' +
                    ", img1='" + img1 + '\'' +
                    ", img2='" + img2 + '\'' +
                    ", ptime='" + ptime + '\'' +
                    '}';
        }
    }

}

注释已经在代码中详细说明，就不做太多解释了，着重说一点，ResultSubscriber.java中的mRequestType是用来在连续多次请求网络接口时，需要在界面中做不同的处理而区分的属性。使用时，最好也为每个接口配置为对应的唯一值。

附上GitHub地址，https://github.com/QiYuan007/EasyFrame 如果本文对你有帮助，多多start。

如果你有更好的实现方式，请与我联系。