project-reactor

I have a spring web application. When a user calls save endpoint, system should execute many external calls to save the state in multiple microservices. However, those steps depend on each other. In other words I have a sequence of steps to perform. sequence pattern Just calling a set of steps one by one is not a big deal, I can just create class for each step and call them one by one doing appropriate modifications between the steps. However, each of the steps can fail and if it happens it should be properly reported to the user. Here is a pseudo-code for a straight forward solution: var

I have a requirement where I read a bunch of rows (thousands) from a SQL DB using Spring Batch and call a REST Service to enrich content before writing them on a Kafka topic. When using the Spring Reactive webClient, how do I limit the number of active non-blocking service calls? Should I somehow introduce a Flux in the loop after I read data using Spring Batch? (I understand the usage of delayElements and that it serves a different purpose, as when a single Get Service Call brings in lot of data and you want the server to slow down -- here though, my use case is a bit different in that I have

I have a simple Java program that sends multiple requests with Spring WebClient. Each returns a mono, and I am using response.subscribe() to check the result. However, my main thread of execution finishes before all requests are processed, unless I add a long Thread.sleep(). With CompletableFutures you can use: CompletableFuture.allOf(futures).join(); Is there a way to wait for all Mono's to complete ? As explained in the Project Reactor documentation , nothing happens until you subscribe to a Publisher . That operation returns an instance of Disposable , meaning that operation may still be

How does one use a Mono.error(<Throwable>) but attach information from the body returned from a request? Is there a reactive object that extends Throwable that takes a Mono/Flux object, so the error being thrown will wait for the body to be accounted for? Or is there a way to add some sort of 'flag' onto an existing Mono object to make it fail instantly (to circumvent the requirement to be Throwable ) Example scenario below: import org.springframework.web.reactive.function.client.WebClient; private someMethod() { webClient.get().retrieve().onStatus(HttpStatus::isError, this::errorHandler) }

I'm having a controller like this one (in Kotlin): @RestController @RequestMapping("/") class CustomerController (private val service: CustomerService) { @GetMapping("/{id}") fun findById(@PathVariable id: String, @RequestHeader(value = IF_NONE_MATCH) versionHeader: String?): Mono<HttpEntity<KundeResource>> = return service.findById(id) .switchIfEmpty(Mono.error(NotFoundException())) .map { // ETag stuff ... ok().eTag("...").body(...) } } Im wondering whether there is a better approach than throwing an exception which is annotated with @ResponseStatus(code = NOT_FOUND) I would like use

A sample project is located here: https://github.com/codependent/spring5-playground I would like to bridge a message received from a JMS queue into a Reactive Controller that would publish the messages as an event stream. I don't want the messages to be replayed, that is, if a message arrives and there isn't any subscriber I don't want them to be sent later when any subsbribes, so I am using an EmitterProcessor: @Component public class AlertEmitterProcessor { private Logger logger = LoggerFactory.getLogger(getClass()); private EmitterProcessor<Alert> processor; public AlertEmitterProcessor(){

I've got a web service that I'm trying to consume with the new Spring 5 WebClient. Working example # GET /orders/ [ { orderId: 1, ... }, { orderId: 1, ... } ] And the java code for the call // Java Flux<Order> ordersStream = webClient.get() .uri("/orders/") .exchange() .flatMap(response -> response.bodyToFlux(Order.class)); Problem The response from the web service is paginated and therefore doesn't contain the list of items directly as in the example above. It looks like this # GET /orders/ { "error": null, "metadata": { "total": 998, "limit": 1000, "offset": 0 }, "data": [ { orderId: 1, ...