Getting data with RxJava and retrofit

Question

I am using RxJava with retrofit to get data from an API then filtering the data with a for loop in the onNext Method. Is there any way not to use the for loop and just use RxJava to filter or improve the code?

 _subscriptions.add(
 jamSpeakServiceApi.getAllWords()
 .subscribeOn(Schedulers.io())
 .observeOn(AndroidSchedulers.mainThread())
 .subscribe(new Observer<List<WordApi>>() {
 @Override
 public void onCompleted() {
 Log.d("retroffit Completed", "Completed");
 }
 @Override
 public void onError(Throwable e) {
 Log.d("retroffit error", e.toString());
 }
 @Override
 public void onNext(List<WordApi> wordApis) {
 /*Observable.from(wordApis)
 .filter(s -> Word.getWordFormDatabase(s.getWord()) != null)
 .filter(s -> s.getCountry().toLowerCase().equals("jamaica"))
 .filter(s -> Word.getWordLikeFormDatabase(s.getWord()) != null)
 .subscribe();*/
 for (WordApi x: wordApis){
 if(x.getCountry().toLowerCase().equals("jamaica")== true){
 Word.saveWordFromApi(x);
 Log.d(x.getWord(),x.getWord());
 }
 }
 }
 })
 );

• Volodymyr: Take a look at this blog blog.danlew.net/2014/09/22/grokking-rxjava-part-2 it's quite long, but you can find here what you are looking for

Answer 1

You should use flat to emit each wordApi and then you will be able to filter your data and apply your function one by one.

Your stream should look like this:

jamSpeakServiceApi.getAllWords()
 .subscribeOn(Schedulers.io())
 .flatMap(wordApis -> Observable.from(wordApis))
 .filter(wordApi -> wordApi.getCountry().toLowerCase().equals("jamaica"))
 .observeOn(AndroidSchedulers.mainThread())
 .subscribe(new Observer<WordApi>() {
 @Override
 public void onCompleted() {
 Log.d("retroffit Completed", "Completed");
 }
 @Override
 public void onError(Throwable e) {
 Log.d("retroffit error", e.toString());
 }
 @Override
 public void onNext(WordApi wordApi) {
 Word.saveWordFromApi(wordApi);
 Log.d(wordApi.getWord(),wordApi.getWord());
 }
 })

I used some lambdas, and I recommend you to use them too. Take a look at the Retrolambda Gradle plugin. It works well with an Android environment.