RxJava. Sequential execution

Question

In my Android App I have a presenter which handles user interactions, contains kind of request manager and if needed sends user input over request manager to request manager.

Answer 1

i suggest to create asynchronous observable methods , here a sample :

public Observable sendRequest(int x){
    return Observable.defer(() -> {
        System.out.println("Sending Request : you get Here X ");
        return storeYourData(x);
    });
}

public Observable storeYourData(int x){
    return Observable.defer(() -> {
        System.out.println("X Stored : "+x);
        return readAnswers(x);
    }).doOnError(this::handlingStoreErrors);
}

public Observable readAnswers(int h){
    return Observable.just(h);
}

public void handlingStoreErrors(Throwable throwable){
        //Handle Your Exception.
}

the first observable will send request when he get response will proceed the second one and you can chain , you can customize each method to handle errors or success, this sample like queue.

here the result for execution :

for (int i = 0; i < 1000; i++) {
        rx.sendRequest(i).subscribe(integer -> System.out.println(integer));

}
Sending Request : you get Here X 
X Stored : 0
0
Sending Request : you get Here X 
X Stored : 1
1
Sending Request : you get Here X 
X Stored : 2
2
Sending Request : you get Here X 
X Stored : 3
3
.
.
.
Sending Request : you get Here X 
X Stored : 996
996
Sending Request : you get Here X 
X Stored : 997
997
Sending Request : you get Here X 
X Stored : 998
998
Sending Request : you get Here X 
X Stored : 999
999