RxJava+Retrofit入门

• Grokking RxJava, Part 1: The Basics
• Grokking RxJava, Part 2: Operator, Operator
• Grokking RxJava, Part 3: Reactive with Benefits
• Grokking RxJava, Part 4: Reactive Android
• 给 Android 开发者的 RxJava 详解
• 用 Retrofit 2 简化 HTTP 请求

Sample 1: RxJava的Hello World

private Subscriber<String> mSubscriber = new Subscriber<String>() {
    @Override
    public void onCompleted() {
        Log.d(TAG, "onCompleted");
    }
    @Override
    public void onError(Throwable e) {
        Log.d(TAG, "onError");
    }
    @Override
    public void onNext(String s) {
        Log.d(TAG, "onNext # " + s);
    }
};

...

Observable<String> observable = Observable.create(new Observable.OnSubscribe<String>() {
    @Override
    public void call(Subscriber<? super String> subscriber) {
        subscriber.onNext("hello world");
        subscriber.onCompleted();
    }
});
observable.subscribe(mSubscriber);

Sample 2: 更简洁的实现

Observable.just("hello world 2").subscribe(new Action1<String>() {
    @Override
    public void call(String s) {
        Log.d(TAG, "simpler # " + s);
    }
});

Sample 3: map转换操作

Observable.just("hello world 3")
        .map(new Func1<String, String>() {
            @Override
            public String call(String s) {
                return s + " from syl";
            }
        })
        .subscribe(new Action1<String>() {
            @Override
            public void call(String s) {
                Log.d(TAG, "transform # " + s);
            }
        });

**Sample 4: **

Network.getGitHubApi().rxListRepo("octocat")
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .flatMap(new Func1<List<Repo>, Observable<Repo>>() {
            @Override
            public Observable<Repo> call(List<Repo> repos) {
                return Observable.from(repos);
            }
        })
        .filter(new Func1<Repo, Boolean>() {
            @Override
            public Boolean call(Repo repo) {
                return repo != null;
            }
        })
        .take(3)
        .subscribe(new Action1<Repo>() {
            @Override
            public void call(Repo repo) {
                Log.d(TAG, "" + repo.getFull_name());
            }
        });

RxSamples：RxJava 和 Retrofit 结合使用的几个最常见使用方式举例。

• 1 基本：subscribeOn() + observeOn()

private void search(String key) {
    subscription = Network.getZhuangbiApi()
            .search(key)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(observer);
}

• 2 转换：map()

• 3 压合：zip()

• 4 Token：flatMap()
  获取token -> 请求网络数据with token

@OnClick(R.id.requestBt)
void upload() {
    swipeRefreshLayout.setRefreshing(true);
    unsubscribe();
    final FakeApi fakeApi = Network.getFakeApi();
    subscription = fakeApi.getFakeToken("fake_auth_code")
            .flatMap(new Func1<FakeToken, Observable<FakeThing>>() {
                @Override
                public Observable<FakeThing> call(FakeToken fakeToken) {
                    return fakeApi.getFakeData(fakeToken);
                }
            })
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(new Action1<FakeThing>() {
                @Override
                public void call(FakeThing fakeData) {
                    swipeRefreshLayout.setRefreshing(false);
                    tokenTv.setText(getString(R.string.got_data, fakeData.id, fakeData.name));
                }
            }, new Action1<Throwable>() {
                @Override
                public void call(Throwable throwable) {
                    swipeRefreshLayout.setRefreshing(false);
                    Toast.makeText(getActivity(), R.string.loading_failed, Toast.LENGTH_SHORT).show();
                }
            });
}

• 5 Token高级：flatMap() + retryWhen()

流程图

• 6 缓存：BehaviorSubject<T>
  内存缓存 -> 磁盘缓存 -> 请求网络数据