android - How to return value with RxJava? -

let's consider situation. have class has 1 method returns value:

public class foo() {     observer<file> fileobserver;     observable<file> fileobservable;     subscription subscription;      public file getmethatthing(string id) {         // implement logic in observable<file> , return value         // emitted in onnext(file)     } } 

how return value received in onnext? correct approach? thank you.

you need better understanding of rxjava first, observable -> push model is. solution 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 app public void doingthings(){   ...   // synchronous   foo.getmethatthing(5)    .subscribe(new onsubscribed<file>(){      public void onnext(file file){ // file }      public void oncomplete(){  }      public void onerror(throwable t){ // error cases }   });    // asynchronous, each observable subscription whole operation scratch   foo.getmethatthing("5")    .subscribeon(schedulers.newthread())    .subscribe(new onsubscribed<file>(){      public void onnext(file file){ // file }      public void oncomplete(){  }      public void onerror(throwable t){ // error cases }   });    // synchronous , blocking, run operation on thread while current 1 stopped waiting.   // warning, danger, never in main/ui thread or may freeze app   file file =    foo.getmethatthing("5")    .subscribeon(schedulers.newthread())    .toblocking().first();   .... }