RxJava : fromIterable is not emitting all the items
I was trying out a simple code with fromIterable and flatMap operators. I'm just mapping a stream of long values to a stream of Result in my code. Nothing else
Here's my code.
I have an empty class
class Result {
@Override
public String toString() {
return "result";
}
}
And a function
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.flatMap( aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
And I subscribe to this as follows
List<Long> ids = new ArrayList<>(Arrays.asList(1L, 2L, 3L));
getResults(ids)
.subscribe(new DisposableObserver<Result>() {
@Override
public void onNext(Result item) {
Log.d(TAG, "onNext: " + item);
}
@Override
public void onComplete() {
Log.d(TAG, "onCompleted: ");
}
@Override
public void onError(Throwable e) {
Log.e(TAG, "onError: " + e.getMessage());
}
});
My expected output is
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
For each emission of fromIterable , the flatMap expected to return a stream with 2 values, so total 6 times onNext and then onComplete
But what I'm getting is
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Only 2 times onNext is triggering and then it completes. Where did the remaining 4 values go?
But the strange thing is , I added a Log to the doOnNext of fromIterable in my getResults function as follows
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.doOnNext(i -> Log.d(TAG, "fromIterable emitted " + i))
.flatMap(aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
Now it is emitting all the values!!!! Here's the output
LOG: fromIterable emitted 1
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 2
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 3
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Whats happenning here? What change did the onNext make to the chain to emit all the values?
android rx-java rx-java2 asked Nov 22 '18 at 6:37
doedoe
6510
add a comment |
I was trying out a simple code with fromIterable and flatMap operators. I'm just mapping a stream of long values to a stream of Result in my code. Nothing else
Here's my code.
I have an empty class
class Result {
@Override
public String toString() {
return "result";
}
}
And a function
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.flatMap( aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
And I subscribe to this as follows
List<Long> ids = new ArrayList<>(Arrays.asList(1L, 2L, 3L));
getResults(ids)
.subscribe(new DisposableObserver<Result>() {
@Override
public void onNext(Result item) {
Log.d(TAG, "onNext: " + item);
}
@Override
public void onComplete() {
Log.d(TAG, "onCompleted: ");
}
@Override
public void onError(Throwable e) {
Log.e(TAG, "onError: " + e.getMessage());
}
});
My expected output is
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
For each emission of fromIterable , the flatMap expected to return a stream with 2 values, so total 6 times onNext and then onComplete
But what I'm getting is
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Only 2 times onNext is triggering and then it completes. Where did the remaining 4 values go?
But the strange thing is , I added a Log to the doOnNext of fromIterable in my getResults function as follows
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.doOnNext(i -> Log.d(TAG, "fromIterable emitted " + i))
.flatMap(aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
Now it is emitting all the values!!!! Here's the output
LOG: fromIterable emitted 1
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 2
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 3
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Whats happenning here? What change did the onNext make to the chain to emit all the values?
android rx-java rx-java2 asked Nov 22 '18 at 6:37
doedoe
6510
2
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16
add a comment |
I was trying out a simple code with fromIterable and flatMap operators. I'm just mapping a stream of long values to a stream of Result in my code. Nothing else
Here's my code.
I have an empty class
class Result {
@Override
public String toString() {
return "result";
}
}
And a function
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.flatMap( aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
And I subscribe to this as follows
List<Long> ids = new ArrayList<>(Arrays.asList(1L, 2L, 3L));
getResults(ids)
.subscribe(new DisposableObserver<Result>() {
@Override
public void onNext(Result item) {
Log.d(TAG, "onNext: " + item);
}
@Override
public void onComplete() {
Log.d(TAG, "onCompleted: ");
}
@Override
public void onError(Throwable e) {
Log.e(TAG, "onError: " + e.getMessage());
}
});
My expected output is
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
For each emission of fromIterable , the flatMap expected to return a stream with 2 values, so total 6 times onNext and then onComplete
But what I'm getting is
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Only 2 times onNext is triggering and then it completes. Where did the remaining 4 values go?
But the strange thing is , I added a Log to the doOnNext of fromIterable in my getResults function as follows
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.doOnNext(i -> Log.d(TAG, "fromIterable emitted " + i))
.flatMap(aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
Now it is emitting all the values!!!! Here's the output
LOG: fromIterable emitted 1
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 2
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 3
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Whats happenning here? What change did the onNext make to the chain to emit all the values?
android rx-java rx-java2 asked Nov 22 '18 at 6:37
doedoe
6510
I was trying out a simple code with fromIterable and flatMap operators. I'm just mapping a stream of long values to a stream of Result in my code. Nothing else
Here's my code.
I have an empty class
class Result {
@Override
public String toString() {
return "result";
}
}
And a function
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.flatMap( aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
And I subscribe to this as follows
List<Long> ids = new ArrayList<>(Arrays.asList(1L, 2L, 3L));
getResults(ids)
.subscribe(new DisposableObserver<Result>() {
@Override
public void onNext(Result item) {
Log.d(TAG, "onNext: " + item);
}
@Override
public void onComplete() {
Log.d(TAG, "onCompleted: ");
}
@Override
public void onError(Throwable e) {
Log.e(TAG, "onError: " + e.getMessage());
}
});
My expected output is
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
For each emission of fromIterable , the flatMap expected to return a stream with 2 values, so total 6 times onNext and then onComplete
But what I'm getting is
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Only 2 times onNext is triggering and then it completes. Where did the remaining 4 values go?
But the strange thing is , I added a Log to the doOnNext of fromIterable in my getResults function as follows
public Observable<Result> getResults(List<Long> requests) {
return Observable.fromIterable(requests)
.doOnNext(i -> Log.d(TAG, "fromIterable emitted " + i))
.flatMap(aLong -> {
Result items = {new Result(), new Result()};
return Observable.fromIterable(Arrays.asList(items));
});
}
Now it is emitting all the values!!!! Here's the output
LOG: fromIterable emitted 1
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 2
LOG: onNext: result
LOG: onNext: result
LOG: fromIterable emitted 3
LOG: onNext: result
LOG: onNext: result
LOG: onCompleted:
Whats happenning here? What change did the onNext make to the chain to emit all the values?
android rx-java rx-java2 android rx-java rx-java2 asked Nov 22 '18 at 6:37
doedoe
6510
asked Nov 22 '18 at 6:37
doedoe
6510
asked Nov 22 '18 at 6:37
doedoe
6510
asked Nov 22 '18 at 6:37
doedoe
6510
asked Nov 22 '18 at 6:37
doedoe
6510
6510
2
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16
add a comment |
2
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16
2
2
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16
add a comment |
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2
The likely reason you don't see all logs is because of Log deduplicating similar messages if they appear too close to each other. If you log unique messages, all 6 onNexts should appear.
– akarnokd
Nov 22 '18 at 8:31
@akarnokd Ohh.. So it seems to be a logging issue. Nothing to do with RxJava right?
– doe
Nov 22 '18 at 9:16