《Android 应用之路》 Android 开发技术选型（博客，新闻，阅读类）

private void initBGALayout() {
    // 为BGARefreshLayout 设置代理
    bgaRefreshLayout.setDelegate(this);
    // 设置下拉刷新和上拉加载更多的风格     参数1：应用程序上下文，参数2：是否具有上拉加载更多功能

    BGANormalRefreshViewHolder refreshViewHolder =
            new BGANormalRefreshViewHolder(getContext(), true);
    refreshViewHolder.setLoadingMoreText("加载更多");
    refreshViewHolder.setLoadMoreBackgroundColorRes(R.color.white);
    refreshViewHolder.setRefreshViewBackgroundColorRes(R.color.white);
    bgaRefreshLayout.setRefreshViewHolder(refreshViewHolder);
}

public interface JuheApi {
    @GET
    Observable<NewsBean> getNews(@Url String url);

    @GET
    Observable<FunnyBean> getFunny(@Url String url);

    @GET
    Observable<JokeBean> getJoke(@Url String url);

    @GET
    Observable<HistoryBean> getTodayInHistory(@Url String url);

    @GET
    Observable<QueryNewsBean> getQueryNews(@Url String url);
}

public class Retrofitance {
    public static final String BASE_URL = "http://gank.io/api/";

    private static final int DEFAULT_TIMEOUT = 5;

    private Retrofit retrofit;
    private JuheApi mJuheApi;
    private OkHttpClient mOkHttpClient;

    //构造方法私有
    private Retrofitance() {
        //手动创建一个OkHttpClient并设置超时时间
        OkHttpClient.Builder httpClientBuilder = new OkHttpClient.Builder();
        httpClientBuilder.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS);
        mOkHttpClient = httpClientBuilder.build();

        retrofit = new Retrofit.Builder().client(mOkHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .baseUrl(BASE_URL)
                .build();

        mJuheApi = retrofit.create(JuheApi.class);
    }

    //获取单例
    public static Retrofitance getInstance() {
        return SingletonHolder.INSTANCE;
    }

    /**
     * 根据类型获取新闻信息
     */
    public void getNews(Observer<NewsBean> subscriber, String type) {
        String URL = "";
        commonOp(mJuheApi.getNews(URL),subscriber);
    }

    /**
     * 获取趣图信息
     */
    public void getFunny(Observer<FunnyBean> subscriber, int pagenum) {
        String URL ="";
        commonOp(mJuheApi.getFunny(URL), subscriber);
    }

    /**
     * 获取历史上的今天
     */
    public void getHistory(Observer<HistoryBean> subscriber) {
        Calendar now = Calendar.getInstance();
        String URL = "";
        commonOp(mJuheApi.getTodayInHistory(URL),subscriber);
    }

    /**
     * 获取笑话大全
     */
    public void getJoke(Observer<JokeBean> subscriber, int pagenum) {
        String URL ="";
        commonOp(mJuheApi.getJoke(URL), subscriber);
    }


    public void getQueryNews(Observer<QueryNewsBean> subscriber, String keyword) {
        String URL = "";
        commonOp(mJuheApi.getQueryNews(URL), subscriber);
    }

    private void commonOp(Observable observable, Observer subscriber) {
        observable.subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(subscriber);
    }
    //在访问HttpMethods时创建单例
    private static class SingletonHolder {
        private static final Retrofitance INSTANCE = new Retrofitance();
    }
}

public void getContent(int pagenum) {
    Observer<FunnyBean> observer = new Observer<FunnyBean>() {
        @Override
        public void onComplete() {
            endLoading();
        }

        @Override
        public void onError(Throwable e) {
            e.printStackTrace();
            endLoading();
            onNetworkError();
        }

        @Override
        public void onSubscribe(Disposable d) {

        }

        @Override
        public void onNext(FunnyBean funnyBean) {
            if (bgaRefreshLayout.isLoadingMore()) {
            } else {
                mVisitableList.clear();
            }
            if (funnyBean.getResult() == null || funnyBean.getResult().getData() == null
                    || funnyBean.getResult().getData().size() == 0) {
                onDataEmpty();
            } else {
                mVisitableList.addAll(funnyBean.getResult().getData());
            }
            mMultiRecyclerAdapter.setData(mVisitableList);
        }
    };
    Retrofitance.getInstance().getFunny(observer, pagenum);
}

@BindView(R.id.tl_web)
Toolbar tlWeb;
@BindView(R.id.wv_content)
WebView wvContent;
@BindView(R.id.activity_web)
LinearLayout activityWeb;
@BindView(R.id.progressbar)
ProgressBar progressbar;

....
ButterKnife.bind(this);

Glide.with(itemView.getContext()).load(pic1path).placeholder(R.mipmap.empty_data).into(imageView);

retrofit = new Retrofit.Builder().client(mOkHttpClient)
                /*This is the key*/ 
               .addConverterFactory(GsonConverterFactory.create())         .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                .baseUrl(BASE_URL)
                .build();

switch (i) {
    case 0:
        textView.setText("资讯");
        imageView.setImageResource(R.drawable.news);
        tabHost.addTab(tabHost.newTabSpec("1").setIndicator(view).setContent(
                R.id.frag_news));
        break;
    case 1:
        textView.setText("笑话");
        imageView.setImageResource(R.drawable.joke);
        tabHost.addTab(tabHost.newTabSpec("2").setIndicator(view).setContent(
                R.id.frag_joke));
        break;
    case 2:
        textView.setText("趣图");
        imageView.setImageResource(R.drawable.funny);
        tabHost.addTab(tabHost.newTabSpec("3").setIndicator(view).setContent(
                R.id.frag_funny));
        break;
    case 3:
        textView.setText("历史");
        imageView.setImageResource(R.drawable.history);
        tabHost.addTab(tabHost.newTabSpec("4").setIndicator(view).setContent(
                R.id.frag_history));
        break;
    default:
        break;
}