RxJava2 + Retrofit2 优雅简洁封装

   <h3>RxJava2 封装主要变化</h3>    <ul>     <li>Transformer的变化:RxJava1.X为rx.Observable.Transformer接口, 继承自Func1<Observable<T>, Observable<R>>, RxJava2.X为io.reactivex.ObservableTransformer<Upstream, Downstream>,是一个独立的接口。</li>     <li>Flowable则是FlowableTransformer，如果你使用Flowable，以下ObservableTransformer替换FlowableTransformer即可。</li>    </ul>    <p><img src="https://simg.open-open.com/show/5a0cbeb1841ada2094156425d23f4d1d.jpg"></p>    <p>RxJava2 + Retrofit2.jpg</p>    <h3>封装方案</h3>    <p>1、封装 Rx 线程相关</p>    <p>RxSchedulersHelper：</p>    <pre>  <code class="language-java">/**   * Created by weiss on 17/1/16.   */  public class RxSchedulers {      public static <T> ObservableTransformer<T, T> io_main() {          return upstream ->                  upstream.subscribeOn(Schedulers.io())                  .observeOn(AndroidSchedulers.mainThread());      }  }</code></pre>    <p>封装后：</p>    <pre>  <code class="language-java">Api.getInstance().movieService                  .getGankData("Android",1)                  .compose(RxSchedulers.io_main());</code></pre>    <p>2、封装 处理服务器返回数据，管理 RxJava生命周期</p>    <p>HttpResult：</p>    <pre>  <code class="language-java">/**   * Created by Weiss on 2017/1/11.   */    public class HttpResult<T> 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;      }  }</code></pre>    <p>BaseRxActivity：</p>    <pre>  <code class="language-java">/**   * 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 <T>       * @return       */      public <T> ObservableTransformer<HttpResult<T>, 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 <T> Observable<T> 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;      }  }</code></pre>    <p>封装后 (BaseRxActivity的子类使用)：</p>    <pre>  <code class="language-java">addRxDestroy(Api.getInstance().movieService                  .getGankData("Android",1)                  .compose(RxSchedulers.io_main())                  .compose(handleResult())                  .省略  );</code></pre>    <p>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。</p>    <p>3、异常处理</p>    <pre>  <code class="language-java">/**   * Created by Weiss on 2017/2/9.   */    public class RxException<T extends Throwable> implements Consumer<T> {        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<? super Throwable> onError;      public RxException(Consumer<? super Throwable> 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);          }      }  }</code></pre>    <p>封装后 (BaseRxActivity的子类使用)：</p>    <pre>  <code class="language-java">addRxDestroy(Api.getInstance().movieService                  .getGankData("Android",1)                  .compose(RxSchedulers.io_main())                  .compose(handleResult())                  .subscribe(httpResult -> adapter.setItems(httpResult.data),                                  new RxException<>(e ->e.printStackTrace()))  );</code></pre>    <p>4、多页请求封装</p>    <p>实体类：</p>    <pre>  <code class="language-java">/**   * Created by Weiss on 2017/1/20.   */    public class Gank extends BaseListEntity {      @Override      public Flowable<HttpResult<List<Gank>>> getPage(int page) {          return GankApi.getInstance().service.getGankData(param.get("gank"), page)                  .compose(RxSchedulers.io_main());      }    }</code></pre>    <p>实体类继承 BaseListEntity，实现getPage方法即可。</p>    <p>UI视图：</p>    <pre>  <code class="language-java">public class MainActivityFragment extends BaseRxFragment {      @BindView(R.id.baseRecyclerView)      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());      }  }</code></pre>    <p>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自动获取数据。</p>    <p>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。</p>    <h3>后记</h3>    <p>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。</p>    <p> </p>    <p> </p>    <p>来自：http://www.jianshu.com/p/4005bc4a20f2</p>    <p> </p>