Question

我在我的Android应用中使用Retrofit和RxJava，以及我的代码：

public void getConfig(NetworkSubscriber subscriber) {
    Observable<Config> observable = mApi.getConfig();
    observable.subscribeOn(Schedulers.newThread())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(subscriber);
}

public void getCode(String mobile, int type, NetworkSubscriber subscriber) {
    Observable<BaseMessageEntity> observable = mApi.getCode(mobile, type);
    observable.subscribeOn(Schedulers.newThread())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(subscriber);
}

我不想写.subscribeOn(Schedulers.newThread())和 .observeOn(AndroidSchedulers.mainThread())每种商业方法

我该怎么办？

Answer 1

如果您不想在每次调用时指定所需的线程，则可以在RxJavaCallAdapterFactory周围创建一个包装器，以便默认设置您的线程。

public class RxThreadCallAdapter extends CallAdapter.Factory {

    RxJavaCallAdapterFactory rxFactory = RxJavaCallAdapterFactory.create();
    private Scheduler subscribeScheduler;
    private Scheduler observerScheduler;

    public RxThreadCallAdapter(Scheduler subscribeScheduler, Scheduler observerScheduler) {
        this.subscribeScheduler = subscribeScheduler;
        this.observerScheduler = observerScheduler;
    }

    @Override
    public CallAdapter<?> get(Type returnType, Annotation[] annotations, Retrofit retrofit) {
        CallAdapter<Observable<?>> callAdapter = (CallAdapter<Observable<?>>) rxFactory.get(returnType, annotations, retrofit);
        return callAdapter != null ? new ThreadCallAdapter(callAdapter) : null;
    }

    final class ThreadCallAdapter implements CallAdapter<Observable<?>> {
        CallAdapter<Observable<?>> delegateAdapter;

        ThreadCallAdapter(CallAdapter<Observable<?>> delegateAdapter) {
            this.delegateAdapter = delegateAdapter;
        }

        @Override public Type responseType() {
            return delegateAdapter.responseType();
        }

        @Override
        public <T> Observable<?> adapt(Call<T> call) {
            return delegateAdapter.adapt(call).subscribeOn(subscribeScheduler)
              .observeOn(observerScheduler);
        }
    }
}

然后在构建器中使用它而不是RxJavaCallAdapterFactory.create() -

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://api.github.com/")
    .addConverterFactory(GsonConverterFactory.create())
    .addCallAdapterFactory(new RxThreadCallAdapter(Schedulers.io(), AndroidSchedulers.mainThread()))
    .build();

Answer 2

要拥有subscribeOn的默认计划程序，您可以在创建RxJavaCallAdapterFactory实例时将其作为参数直接传递给Retrofit：

new Retrofit.Builder()
            .client(okHttpClient)
            .addCallAdapterFactory(RxJavaCallAdapterFactory.createWithScheduler(Schedulers.io()))
            .build();

在Retrofit 2.0.0中引入

Answer 3

您可以使用compose()将其缩小到一行。例如，下面是getConfig()方法的修改版本。它假设您使用的是retrolambda。

public void getConfig(NetworkSubscriber subscriber) {
    Observable<Config> observable = mApi.getConfig();
    observable
            .compose(this::setupThreads)
            .subscribe(subscriber);
}

setupThreads()方法如下所示：

private <T> Observable<T> setupThreads(final Observable<T> observable) {
    return observable
            .subscribeOn(Schedulers.newThread())
            .observeOn(AndroidSchedulers.mainThread());
}

一些参考文献：

RxJava Wiki - Transformational Operators
Dan Lew博文 - Don't break the chain: use RxJava's compose() operator

改造默认线程

3 个答案: