Spring Webflux - Publish all HTTP requests to pubsub - spring

Question

In my app I have one endpoint under /my-endpoint path which supports only post method. It accepts a body that must be compatible with my MyRequest class.
#Validated
data class MyRequest(
#get:JsonProperty("age", required = true)
#field:Size(min = 3, max = 128, message = "age must be between 3 and 128")
val age: String,
#get:JsonProperty("zip_code", required = true)
#field:Pattern(regexp = "\\d{2}-\\d{3}", message = "address.zip_code is invalid. It is expected to match pattern \"\\d{2}-\\d{3}\"")
val zipCode: String
)
And my controller looks like this
#PostMapping("/my-endpoint")
fun myEndpoint(
#Valid #RequestBody request: MyRequest,
): Mono<ResponseEntity<MyResponse>> {
return myService.processRequest(request)
.map { ResponseEntity.ok().body(it) }
}
Each time I receive some request to THIS particular endpoint (I have other endpoints but them should be ignored) - I'd like to publish a message to my pubsub consisting raw request body (as a string) - no matter whether the request body was valid or not.
How to intercept the request to be able to publish the message - still having the endpoint working ?

Answer 1

I think you could implement your own WebFilter. Filter the API path through exchange.getRequest().getPath() using simple if block and get the body through exchange.getRequest().getBody()
#Component
#RequiredArgsConstructor
#Slf4j
public class MyFilter implements WebFilter {
private final MyPublisher myPublisher;
#Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
if (pathMatches(exchange.getRequest().getPath()) {
return exchange.getRequest().getBody()
.map(dataBuffer -> {
final String requestBody = dataBuffer.toString(StandardCharsets.UTF_8));
this.myPublisher.publish(requestBody).subscribe();
return exchange;
}).then(chain.filter(exchange));
}
return chain.filter(exchange);
}
}