RxJava2+Retrofit2优雅简洁封装-白红宇

RxJava2 封装主要变化

Transformer的变化:RxJava1.X为rx.Observable.Transformer接口, 继承自Func1<Observable, Observable>, RxJava2.X为io.reactivex.ObservableTransformer<Upstream, Downstream>,是一个独立的接口。

Flowable则是FlowableTransformer，如果你使用Flowable，以下ObservableTransformer替换FlowableTransformer即可。

封装方案

1、封装 Rx 线程相关

RxSchedulersHelper：

/** * Created by weiss on 17/1/16. */public class RxSchedulers {    public static 
    
      ObservableTransformer
     
       io_main() {        return upstream ->                upstream.subscribeOn(Schedulers.io())                .observeOn(AndroidSchedulers.mainThread());    }}复制代码

封装后：

Api.getInstance().movieService                .getGankData("Android",1)                .compose(RxSchedulers.io_main());复制代码

2、封装处理服务器返回数据，管理 RxJava生命周期

HttpResult：

/** * Created by Weiss on 2017/1/11. */public class HttpResult
    
      implements Serializable {    public String code;    public String msg;    public boolean hasmore;    public T data;    public static String SUCCESS = "000";    public static String SIGN_OUT = "101";//token验证失败    public static String SHOWTOAST = "102";//显示Toast    public boolean isSuccess() {        return SUCCESS.equals(code);    }    public boolean isTokenInvalid() {        return SIGN_OUT.equals(code);    }    public boolean isShowToast() {        return SHOWTOAST.equals(code);    }    public boolean hasMore() {        return hasmore;    }}复制代码

BaseRxActivity：

/** * 管理RxJava生命周期，避免内存泄漏 * RxJava处理服务器返回 * * Created by Weiss on 2016/12/23. */public abstract class BaseRxActivity extends BaseActivity {    private CompositeDisposable disposables2Stop;// 管理Stop取消订阅者者    private CompositeDisposable disposables2Destroy;// 管理Destroy取消订阅者者    protected abstract int getLayoutId();    protected abstract void initView();    /**     * Rx优雅处理服务器返回     *     * @param 
    
          * @return     */    public 
     
       ObservableTransformer
      
       
        , T> handleResult() {        return upstream ->{                return upstream.flatMap(result -> {                            if (result.isSuccess()) {                                return createData(result.data);                            } else if (result.isTokenInvalid()) {                                //处理token失效，tokenInvalid方法在BaseActivity 实现                                 tokenInvalid();                            } else {                                return Observable.error(new Exception(result.msg));                            }                            return Observable.empty();                        }                );        };    }    private 
        
          Observable
         
           createData(final T t) { return Observable.create(subscriber -> { try { subscriber.onNext(t); subscriber.onComplete(); } catch (Exception e) { subscriber.onError(e); } }); } public boolean addRxStop(Disposable disposable) { if (disposables2Stop == null) { throw new IllegalStateException( "addUtilStop should be called between onStart and onStop"); } disposables2Stop.add(disposable); return true; } public boolean addRxDestroy(Disposable disposable) { if (disposables2Destroy == null) { throw new IllegalStateException( "addUtilDestroy should be called between onCreate and onDestroy"); } disposables2Destroy.add(disposable); return true; } public void remove(Disposable disposable) { if (disposables2Stop == null && disposables2Destroy == null) { throw new IllegalStateException("remove should not be called after onDestroy"); } if (disposables2Stop != null) { disposables2Stop.remove(disposable); } if (disposables2Destroy != null) { disposables2Destroy.remove(disposable); } } public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (disposables2Destroy != null) { throw new IllegalStateException("onCreate called multiple times"); } disposables2Destroy = new CompositeDisposable(); } public void onStart() { super.onStart(); if (disposables2Stop != null) { throw new IllegalStateException("onStart called multiple times"); } disposables2Stop = new CompositeDisposable(); } public void onStop() { super.onStop(); if (disposables2Stop == null) { throw new IllegalStateException("onStop called multiple times or onStart not called"); } disposables2Stop.dispose(); disposables2Stop = null; } public void onDestroy() { super.onDestroy(); if (disposables2Destroy == null) { throw new IllegalStateException( "onDestroy called multiple times or onCreate not called"); } disposables2Destroy.dispose(); disposables2Destroy = null; }}复制代码

封装后 (BaseRxActivity的子类使用)：

addRxDestroy(Api.getInstance().movieService                .getGankData("Android",1)                .compose(RxSchedulers.io_main())                .compose(handleResult())                .省略);复制代码

handleResult为什么不新建一个类处理呢？因为很多异常处理需要context对象，或者和BaseActivity有千丝万缕的联系，BaseRxActivity继承BaseActivity可以很简洁优雅处理各种异常。比如token失效，是需要跳转到登录页面的。在新建一个类中，不能持有context对象，只能使用Application的Context，同时方便与Activity通信交互满足各种需求。BaseRxActivity还可以管理RxJava生命周期。

3、异常处理

/** * Created by Weiss on 2017/2/9. */public class RxException
    
      implements Consumer
     
       {    private static final String TAG = "RxException";    private static final String SOCKETTIMEOUTEXCEPTION = "网络连接超时，请检查您的网络状态，稍后重试";    private static final String CONNECTEXCEPTION = "网络连接异常，请检查您的网络状态";    private static final String UNKNOWNHOSTEXCEPTION = "网络异常，请检查您的网络状态";    private Consumer
       onError;    public RxException(Consumer
       onError) {        this.onError=onError;    }    /**     * Consume the given value.     *     * @param t the value     * @throws Exception on error     */    @Override    public void accept(T t) throws Exception {        if (t instanceof SocketTimeoutException) {            Log.e(TAG, "onError: SocketTimeoutException----" + SOCKETTIMEOUTEXCEPTION);            ToastUtils.show(SOCKETTIMEOUTEXCEPTION);            onError.accept(new Throwable(SOCKETTIMEOUTEXCEPTION));        } else if (t instanceof ConnectException) {            Log.e(TAG, "onError: ConnectException-----" + CONNECTEXCEPTION);            ToastUtils.show(CONNECTEXCEPTION);            onError.accept(new Throwable(CONNECTEXCEPTION));        } else if (t instanceof UnknownHostException) {            Log.e(TAG, "onError: UnknownHostException-----" + UNKNOWNHOSTEXCEPTION);            ToastUtils.show(UNKNOWNHOSTEXCEPTION);            onError.accept(new Throwable(UNKNOWNHOSTEXCEPTION));        } else {            Log.e(TAG, "onError:----" + t.getMessage());            onError.accept(t);        }    }}复制代码

封装后 (BaseRxActivity的子类使用)：

addRxDestroy(Api.getInstance().movieService                .getGankData("Android",1)                .compose(RxSchedulers.io_main())                .compose(handleResult())                .subscribe(httpResult -> adapter.setItems(data),                                new RxException<>(e ->e.printStackTrace())));复制代码

4、多页请求封装

实体类：

/** * Created by Weiss on 2017/1/20. */public class Gank extends BaseListEntity {    @Override    public Observable
    
     
      
       >> getPage(int page) {        return GankApi.getInstance().service.getGankData(param.get("gank"), page)                .compose(RxSchedulers.io_main());    }}复制代码

实体类继承 BaseListEntity，实现getPage方法即可。

UI视图：

public class MainActivityFragment extends BaseRxFragment {    @BindView(R.id.ptrRecyclerView)    PtrRecyclerView ptrRecyclerView;    private MultiTypeAdapter adapter;    public MainActivityFragment() {    }    @Override    protected int getLayoutId() {        return R.layout.fragment_main;    }    @Override    protected void initView() {        ptrRecyclerView.setParam("gank","Android");        adapter = new MultiTypeAdapter();        adapter.register(Gank.class,new GankViewProvider());        ptrRecyclerView.setAdapter(adapter,new Gank());    }}复制代码

只需要写一个适配器和实体类，轻松实现多页请求，PtrRecyclerView下拉刷新和上拉加载是会自动调用getPage()方法获取数据。 PtrRecyclerView目前只是简单实现下拉刷新和上拉加载，有空会完善，当然例子也会完善。当然PtrRecyclerView的封装会根据RecyclerView原生的方法名参数，减少学习成本。

后记

还可以封装网络加载对话框，这个看个人喜好，同样以上封装同样可以看个人喜好和项目需求自由组装。