I am using ParallelFlux for running many task.
but when i am receiving webClient response using bodyToFlux method its merging all the output response instead of getting one by one.
i want the output should be one by one not single string, is there any other method instead of bodyToFLux need to use.
request method:
Flux<String> responsePost = webClient.build()
//removed get,url and retrieve here
.bodyToFlux(String.class);
responsePost.subscribe(s -> {
//display response
});
response method:
public ParallelFlux<String> convertListToMap() {
//created list of string str
return Flux.fromIterable(str)
.parallel(3)
.runOn(Schedulers.parallel())
.map( s -> {
//some logic here
});
}
output:
parallel fulx reponse: springwebfluxparellelExample
Here instead of returning ParallelFlux create an
ResponseBody class with variable you want to return, assign your response to
variable inside ResponseBody and return it to caller of API function.
public ParallelFlux<ResponseBody> convertListToMap() {
//created list of string str
return Flux.fromIterable(str)
.parallel(3)
.runOn(Schedulers.parallel())
.map( s -> {
//some logic here
});
}
Flux<String> responsePost = webClient.build()
//removed get,url and retrieve here
.bodyToFlux(ResponseBody.class);
Related
I am trying to get my head around variable propagation using reactor. I have a function as follow where I am trying to pass a variable named requestName from outside the map as follow:
public Mono<ResponseEntity<? extends Object>> myFunction(
final Object request, final String requestName) {
return this.client
.create(request)
.exchangeToMono(
response -> {
final HttpStatus status = response.statusCode();
return response
.bodyToMono(String.class)
.defaultIfEmpty(StringUtils.EMPTY)
.map(
body -> {
if (status.is2xxSuccessful()) {
log.info("{}", requestName);
return ResponseEntity.ok().build();
} else {
return ResponseEntity.badRequest().body(null);
}
});
})
.onErrorResume(ex -> Mono.just(buildErrorFromException(requestName, ex)));
}
or another example would be:
String myvar = "test"
return this.
.login()
.flatMap(
response ->
this.myservice(myvar))
.flatMap(
response2 ->
this.myservice2(myvar))
Is it appropriate ? Or would i need to wrap this function around a Mono.deferContextual and apply a contextView ?
Thanks a lot for your help.
I am trying to upload file using Reactive spring fremework.If I only reqeset file by postman. It works fine. When I added addtional parameter Stirng as uploadType. It is always null. I tried postman as following:-
My controller code:-
#RestController
#RequestMapping(path = "/upload")
public class ReactiveUploadResource {
Logger LOGGER = LoggerFactory.getLogger(ReactiveUploadResource.class);
#RequestMapping(method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
public Flux<String> uploadHandler(#RequestBody Flux<Part> parts, String uploadType) {
return (Flux<String>) parts
.filter(part -> part instanceof FilePart)
.ofType(FilePart.class) // convert the flux to FilePart
.flatMap(item -> saveFile(item, uploadType)); // save each file and flatmap it to a flux of results
}
}
Postman:-
I always get uploadType null. What is wrong? How can pass String or Enum in this reqeust?
I am using spring hexagonal architecture (port and adapter) as my application need to read the stream of data from the source topic, process/transforms the data, and send it to destination topic.
My application need to do the following actions.
Read the data (which will have the call back url)
Make an http call with the url in the incoming data (using webclient)
Get the a actual data and it needs to be transformed into another format.
Send the transformed data to the outgoing topic.
Here is my code,
public Flux<TargeData> getData(Flux<Message<EventInput>> message)
{
return message
.flatMap(it -> {
Event event = objectMapper.convertValue(it.getPayload(), Event.class);
String eventType = event.getHeader().getEventType();
String callBackURL = "";
if (DISTRIBUTOR.equals(eventType)) {
callBackURL = event.getHeader().getCallbackEnpoint();
WebClient client = WebClient.create();
Flux<NodeInput> nodeInputFlux = client.get()
.uri(callBackURL)
.headers(httpHeaders -> {
httpHeaders.setContentType(MediaType.APPLICATION_JSON);
List<MediaType> acceptTypes = new ArrayList<>();
acceptTypes.add(MediaType.APPLICATION_JSON);
httpHeaders.setAccept(acceptTypes);
})
.exchangeToFlux(response -> {
if (response.statusCode()
.equals(HttpStatus.OK)) {
System.out.println("Response is OK");
return response.bodyToFlux(NodeInput.class);
}
return Flux.empty();
});
nodeInputFlux.subscribe( nodeInput -> {
SourceData source = objectMapper.convertValue(nodeInput, SourceData.class);
// return Flux.fromIterable(this.TransformImpl.transform(source));
});
}
return Flux.empty();
});
}
The commented line in the above code is giving the compilation as subscribe method does not allow return types.
I need a solution "without using block" here.
Please help me here, Thanks in advance.
I think i understood the logic. What do you may want is this:
public Flux<TargeData> getData(Flux<Message<EventInput>> message) {
return message
.flatMap(it -> {
// 1. marshall and unmarshall operations are CPU expensive and could harm event loop
return Mono.fromCallable(() -> objectMapper.convertValue(it.getPayload(), Event.class))
.subscribeOn(Schedulers.parallel());
})
.filter(event -> {
// 2. Moving the if-statement yours to a filter - same behavior
String eventType = event.getHeader().getEventType();
return DISTRIBUTOR.equals(eventType);
})
// Here is the trick 1 - your request below return Flux of SourceData the we will flatten
// into a single Flux<SourceData> instead of Flux<List<SourceData>> with flatMapMany
.flatMap(event -> {
// This WebClient should not be created here. Should be a singleton injected on your class
WebClient client = WebClient.create();
return client.get()
.uri(event.getHeader().getCallbackEnpoint())
.accept(MediaType.APPLICATION_JSON)
.exchangeToFlux(response -> {
if (response.statusCode().equals(HttpStatus.OK)) {
System.out.println("Response is OK");
return response.bodyToFlux(SourceData.class);
}
return Flux.empty();
});
})
// Here is the trick 2 - supposing that transform return a Iterable of TargetData, then you should do this and will have Flux<TargetData>
// and flatten instead of Flux<List<TargetData>>
.flatMapIterable(source -> this.TransformImpl.transform(source));
}
I have a method that try use WebClient to return a Mono
#GetMapping("getMatch")
public Mono<Object> getMatch(#RequestParam Long matchId) {
return WebClient.create(OpenDotaConstant.BASE_URL).get()
.uri("/matches/{matchId}", matchId)
.accept(MediaType.APPLICATION_JSON)
.retrieve()
.bodyToMono(Object.class);
}
It can return result that I expected.
Then I try to create another method to support List as params
#GetMapping("getMatches")
public Flux<Object> getMatches(#RequestParam String matchesId) {
List<Long> matchesList = JSON.parseArray(matchesId, Long.class);
return Flux.fromStream(matchesList.parallelStream().map(this::getMatch));
}
But this time return a weird result.
[
{
"scanAvailable": true
},
{
"scanAvailable": true
}
]
I'm new to reactive-programming, What is the correct way to combine Stream and Mono,and then convert to the Flux?
Probably, what you need is the following:
#GetMapping("getMatches")
public Flux<Object> getMatches(#RequestParam String matchesId) {
List<Long> matchesList = JSON.parseArray(matchesId, Long.class);
return Flux.fromStream(matchesList.stream())
.flatMap(this::getMatch);
}
Instead of:
#GetMapping("getMatches")
public Flux<Object> getMatches(#RequestParam String matchesId) {
List<Long> matchesList = JSON.parseArray(matchesId, Long.class);
return Flux.fromStream(matchesList.parallelStream().map(this::getMatch));
}
Notes:
Basically, you expect getMatches endpoint to return Flux<Object>. However, as it is written - it actually returns Flux<Mono<Object>>, therefore you see the strange output. To get Flux<Object>, I suggest, first, create Flux<Long> that are match ids, and then flatMap the result of calling getMatch (that returns Mono<Object>), this finally gives Flux<Object>.
Also, there is no need to use parallelStream(). Because you're already using reactor, everything will be performed concurrently on reactor scheduler.
Problem statement: I have a POST request to a booking-service API that gets a BookingRecord. I map it to extract the values so as to call another fare-service API using WebClient. I receive a Mono<Fare> from that call. I need to check whether the value of getFare() method of BookingRecord type is same as the getFare() of the Fare type returned by the WebClient. If not, I need to raise and exception, and pass it on to the caller. Here caller is another Microservice, ui-service calling the booking-service API (so how should I deal with this, pass the error back or else what is the best thing to do?) or else I will save the new BookingRecord and return the id of that record to the caller. What is the best flow sequence for this? I tried my best without much success and am pasting the code here.
public HandlerFunction<ServerResponse> book = request ->
{
request.bodyToMono(BookingRecord.class)
.map(br ->
{
this.webClient.get()
.uri("/fares/get/{flightNumber}/{flightDate}",
br.getFlightNumber(),
br.getFlightDate())
.retrieve()
.bodyToMono(Fare.class)
.map(f ->
{
if (!f.getFare()
.equals(br.getFare()))
{
throw new RuntimeException("Fare is tampered");
}
else
{
id = bookingRepository.save(br).getId();
}
return id;
})
.subscribe();
return id;
});
return ServerResponse.ok()
.body(BodyInserters.fromObject(id));
};
After much tweaking, this is what I did. Hope its the right thing to do. 1. I raise a 500 Http error from the fare-service itself instead of checking in the booking-service.
public HandlerFunction<ServerResponse> getFare = request ->
{
String flightNumber = request.pathVariable("flightNumber");
String flightDate = request.pathVariable("flightDate");
String fare = request.pathVariable("fare");
Mono<ServerResponse> notFound = ServerResponse.notFound()
.build();
return Mono
.justOrEmpty(faresRepository.getFareByFlightNumberAndFlightDateAndFare(flightNumber,
flightDate,
fare))
.flatMap(f -> ServerResponse.ok()
.contentType(APPLICATION_JSON)
.body(fromObject(f)))
.switchIfEmpty(notFound);
};
Handled the exception like so in booking-service using onStatus() method
public HandlerFunction<ServerResponse> book = request ->
{
logger.info("Inside Book function");
return request.bodyToMono(BookingRecord.class)
.flatMap(br ->
{
logger.info("Calling fare-service");
return this.webClient.get()
.uri("/fares/get/{flightNumber}/{flightDate}/{fare}",
br.getFlightNumber(),
br.getFlightDate(),
br.getFare())
.retrieve()
.onStatus(HttpStatus::isError,
x -> Mono
.error(new RuntimeException("Fare has been tampered with!!")))
.bodyToMono(Fare.class);
})
.map(fare ->
{
logger.info("Saving a BookingRecord");
BookingRecord br = new BookingRecord();
br.setFlightNumber(fare.getFlightNumber());
br.setFlightDate(fare.getFlightDate());
br.setFare(fare.getFare());
long id = bookingRepository.save(br)
.getId();
return id;
})
.flatMap(id -> ServerResponse.ok()
.body(BodyInserters.fromObject(id)));
};
This way, I get an exception for fare tampering or get the id for a successful db save.