有没有一种方法可以使用RxJava在多个线程上运行方法

Question

I'm new to RxJava and I'm trying to figure out if there is an equivalent to running multiple async tasks on various threads in parallel.

I understand the RxJava equivalent of

AsyncTask asyncTask = new AsyncTask<String, Void, ObjectType>(){
    @Override
    protected ObjectType doInBackground(String... params) {
         return someMethod(params[0]);
    }

    @Override
    protected void onPostExecute(ObjectType objectType) {}
}

aynctask.execute();

is

Observable.just(string)
    .subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread())
    .map(this::someMethod)
    .subscribe(new Observer<ObjectType>() {
        @Override
        public void onCompleted() {}

        @Override
        public void onError(Throwable e) {}

        @Override
        public void onNext(ObjectType objectType) {}
    });

But how can I implement in RxJava the equivalent of

asyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);

Answer 1

This question is answered very well by the "Scheduler" section of the Rx Java documentation, located here . I will not attempt to summarise that wealth of information here suffice to say that the equivalent of asyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR); is to get the operators in your cascade of Observable operators to operate on particular schedulers.

In particular, you can use the Schedulers.from(AsyncTask.THREAD_POOL_EXECUTOR) method to execute the operator on a particular java.util.concurrent.Executor .