Let's consider this situation. We have some class which has one method which returns some value:
public class Foo() {
Observer<File> fileObserver;
Observable<File> fileObservable;
Subscription subscription;
public File getMeThatThing(String id) {
// implement logic in Observable<File> and return value which was
// emitted in onNext(File)
}
}
How to return that value which was received in onNext
? What would be the correct approach? Thank you.
You need a better understanding of RxJava first, what the Observable -> push model is. This is the solution for reference:
public class Foo {
public static Observable<File> getMeThatThing(final String id) {
return Observable.defer(() => {
try {
return Observable.just(getFile(id));
} catch (WhateverException e) {
return Observable.error(e);
}
});
}
}
//somewhere in the app
public void doingThings(){
...
// Synchronous
Foo.getMeThatThing(5)
.subscribe(new OnSubscribed<File>(){
public void onNext(File file){ // your file }
public void onComplete(){ }
public void onError(Throwable t){ // error cases }
});
// Asynchronous, each observable subscription does the whole operation from scratch
Foo.getMeThatThing("5")
.subscribeOn(Schedulers.newThread())
.subscribe(new OnSubscribed<File>(){
public void onNext(File file){ // your file }
public void onComplete(){ }
public void onError(Throwable t){ // error cases }
});
// Synchronous and Blocking, will run the operation on another thread while the current one is stopped waiting.
// WARNING, DANGER, NEVER DO IN MAIN/UI THREAD OR YOU MAY FREEZE YOUR APP
File file =
Foo.getMeThatThing("5")
.subscribeOn(Schedulers.newThread())
.toBlocking().first();
....
}
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