一、环境配置

1.1 添加网络权限

 <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

1.2 Retrofit、RxJava工具包加入

 //Rxjava
    compile 'io.reactivex.rxjava2:rxjava:2.1.6'
    compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
    //Retrofit
    compile 'com.squareup.retrofit2:retrofit:2.3.0'
    compile 'com.squareup.retrofit2:converter-gson:2.3.0'
    compile 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
    compile 'com.squareup.okhttp3:logging-interceptor:3.8.0'

1.3 配置Retrofit支持Gson和RxJava

 mRetrofit = new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create(new GsonBuilder().create()))//支持Gson转换
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())//支持RxJava
                .baseUrl(ApiConstants.API_SERVER)
                .client(mClient)
                .build();

1.4 配置Header

Interceptor mHeaderInterceptor = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {
            Request originalRequest = chain.request();
            Request.Builder builder = originalRequest.newBuilder();
            //设置具体的Head内容
            builder.header("timestamp", System.currentTimeMillis() + "");
            Request.Builder requestBuilder =
                    builder.method(originalRequest.method(), originalRequest.body());
            Request request = requestBuilder.build();
            return chain.proceed(request);
        }
    };

1.5 缓存配置

  private Interceptor mCacheInterceptor = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {

            Request request = chain.request();
            if (!NetworkUtils.isNetworkAvailable(Initialization.getContext())) {
                request = request.newBuilder()
                        .cacheControl(CacheControl.FORCE_CACHE).build();
            }else{
                request = request.newBuilder()
                        //网络可用 强制从网络获取数据
                        .cacheControl(CacheControl.FORCE_NETWORK)
                        .build();
            }

            Response response = chain.proceed(request);
            if (NetworkUtils.isNetworkAvailable(MyApplication.getContext())) {
                int maxAge = 60; //缓存一分钟
                String cacheControl = "public,max-age=" + maxAge;
                return response.newBuilder()
                        .header("Cache-Control",cacheControl)
                        .removeHeader("Pragma").build();
            } else {
                int maxStale = 60 * 60 * 24 * 7 * 4;  //4周
                return response.newBuilder()
                        .header("Cache-Control", "public,only-if-cached,max-stale=" + maxStale)
                        .removeHeader("Pragma").build();
            }
        }
    };

1.6 配置OkHttpClient

 //设置缓存路径
        File httpCacheDirectory = new File(MyApplication.getContext().getCacheDir(), "RetrofitCache");
        int cacheSize = 1024 * 1024 * 50; // 50 MiB
        Cache cache = new Cache(httpCacheDirectory, cacheSize);

        HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        mClient = new OkHttpClient.Builder()
                .addInterceptor(loggingInterceptor)//添加日志
                .addInterceptor(mHeaderInterceptor)//添加Header
                .addInterceptor(mCacheInterceptor)//添加缓存
                .addNetworkInterceptor(mCacheInterceptor)
                .cache(cache)
                .connectTimeout(20, TimeUnit.SECONDS)//设置连接超时20秒
                .build();

ApiRetrofit完整代码

package com.wj.rxcode.api;

import com.google.gson.GsonBuilder;
import com.wj.rxcode.MyApplication;
import com.wj.rxcode.utils.NetworkUtils;

import java.io.File;
import java.io.IOException;
import java.util.concurrent.TimeUnit;

import okhttp3.Cache;
import okhttp3.CacheControl;
import okhttp3.Interceptor;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;

public class ApiRetrofit {

    private static ApiRetrofit mApiRetrofit;

    private final Retrofit mRetrofit;

    private OkHttpClient mClient;

    private ApiService mApiService;

    public static ApiRetrofit getInstance() {
        if (mApiRetrofit == null) {
            synchronized (Object.class) {
                if (mApiRetrofit == null) {
                    mApiRetrofit = new ApiRetrofit();
                }
            }
        }
        return mApiRetrofit;
    }

    public ApiService getApiService() {
        return mApiService;
    }

    public ApiRetrofit() {
        //设置缓存路径
        File httpCacheDirectory = new File(MyApplication.getContext().getCacheDir(), "RetrofitCache");
        int cacheSize = 1024 * 1024 * 50; // 50 MiB
        Cache cache = new Cache(httpCacheDirectory, cacheSize);

        HttpLoggingInterceptor loggingInterceptor = new HttpLoggingInterceptor();
        loggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        mClient = new OkHttpClient.Builder()
                .addInterceptor(loggingInterceptor)//添加日志
                .addInterceptor(mHeaderInterceptor)//添加Header
                .addInterceptor(mCacheInterceptor)//添加缓存
                .addNetworkInterceptor(mCacheInterceptor)
                .cache(cache)
                .connectTimeout(20, TimeUnit.SECONDS)//设置连接超时20秒
                .build();

        mRetrofit = new Retrofit.Builder()
                .addConverterFactory(GsonConverterFactory.create(new GsonBuilder().create()))//支持Gson转换
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())//支持RxJava
                .baseUrl(ApiConstants.API_SERVER)
                .client(mClient)
                .build();

        mApiService = mRetrofit.create(ApiService.class);
    }

    //缓存配置
    private Interceptor mCacheInterceptor = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {

            Request request = chain.request();
           if (!NetworkUtils.isNetworkAvailable(Initialization.getContext())) {
                request = request.newBuilder()
                        .cacheControl(CacheControl.FORCE_CACHE).build();
            }else{
                request = request.newBuilder()
                        //网络可用 强制从网络获取数据
                        .cacheControl(CacheControl.FORCE_NETWORK)
                        .build();
            }

            Response response = chain.proceed(request);
            if (NetworkUtils.isNetworkAvailable(MyApplication.getContext())) {
                int maxAge = 60; //缓存一分钟
                String cacheControl = "public,max-age=" + maxAge;
                return response.newBuilder()
                        .header("Cache-Control",cacheControl)
                        .removeHeader("Pragma").build();
            } else {
                int maxStale = 60 * 60 * 24 * 7 * 4;  //4周
                return response.newBuilder()
                        .header("Cache-Control", "public,only-if-cached,max-stale=" + maxStale)
                        .removeHeader("Pragma").build();
            }
        }
    };


    Interceptor mHeaderInterceptor = new Interceptor() {
        @Override
        public Response intercept(Chain chain) throws IOException {
            Request originalRequest = chain.request();
            Request.Builder builder = originalRequest.newBuilder();
            //设置具体的Head内容
            builder.header("timestamp", System.currentTimeMillis() + "");
            Request.Builder requestBuilder =
                    builder.method(originalRequest.method(), originalRequest.body());
            Request request = requestBuilder.build();
            return chain.proceed(request);
        }
    };
}

ApiConstants网络接口常量

package com.wj.rxcode.api;

/**
 * Created by wj on 2017/11/17 13:23.
 */

public class ApiConstants {

    //好奇心日报
    public static final String API_SERVER = "http://app3.qdaily.com/";

    //http://app3.qdaily.com/app3/papers/detail/2014.json
    public static final String API_PAPERS_DETAIL="app3/papers/detail/2014.json";
}

ApiService接口

package com.wj.rxcode.api;


import com.wj.rxcode.bean.PapersDetailBean;

import io.reactivex.Observable;
import retrofit2.http.GET;


public interface ApiService {

    @GET(ApiConstants.API_PAPERS_DETAIL)
    Observable<PapersDetailBean> getPaperDetail();

}

二、使用

package com.wj.rxcode;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import com.wj.rxcode.api.ApiRetrofit;
import com.wj.rxcode.api.ApiService;
import com.wj.rxcode.bean.PapersDetailBean;

import io.reactivex.Observable;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.schedulers.Schedulers;

public class MainActivity extends AppCompatActivity {

    private ApiService apiService;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        apiService = ApiRetrofit.getInstance().getApiService();

        getPaperDetail();

    }


    private void getPaperDetail(){

        Observer<PapersDetailBean> observer= new Observer<PapersDetailBean>() {

            //开始请求
            @Override
            public void onSubscribe(Disposable d) {
                Log.i("RxJava","开始请求");
            }

            //请求完成
            @Override
            public void onComplete() {
                Log.i("RxJava","请求完成");
            }

            //请求失败
            @Override
            public void onError(Throwable e) {
                Log.i("RxJava","请求失败");
            }

            //请求成功
            @Override
            public void onNext(PapersDetailBean bean) {
                Log.i("RxJava","请求成功");
            }
        };

        Observable<PapersDetailBean> paperDetail = apiService.getPaperDetail();
        paperDetail.subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(observer);
    }

}