I am writing a spring 5 web app and my requirement is to get a urlencoded form and in response send url encoded response back
This is Router Function code
#Configuration
public class AppRoute {
#Bean
public RouterFunction<ServerResponse> route(FormHandler formHandler) {
return RouterFunctions.route()
// .GET("/form", formHandler::sampleForm)
// .POST("/form", accept(MediaType.APPLICATION_FORM_URLENCODED), formHandler::displayFormData)
.POST("/formnew", accept(MediaType.APPLICATION_FORM_URLENCODED).and(contentType(MediaType.APPLICATION_FORM_URLENCODED)), formHandler::newForm)
.build();
}
}
and here's my Handler code
public Mono<ServerResponse> newForm(ServerRequest request) {
Mono<MultiValueMap<String, String>> formData = request.formData();
MultiValueMap<String, String> newFormData = new LinkedMultiValueMap<String, String>();
formData.subscribe(p -> newFormData.putAll(p));
newFormData.add("status", "success");
return ServerResponse.ok().contentType(MediaType.APPLICATION_FORM_URLENCODED)
.body(fromObject(newFormData));
}
Here's the error I get
2020-04-07 02:37:33.329 DEBUG 38688 --- [ctor-http-nio-3] org.springframework.web.HttpLogging : [07467aa5] Resolved [UnsupportedMediaTypeException: Content type 'application/x-www-form-urlencoded' not supported for bodyType=org.springframework.util.LinkedMultiValueMap] for HTTP POST /formnew
Whats the issue here. I couldn't find any way to write the url encoded response back.
Could anyone point what's the issue.
Try to refactor your code to functional style:
public Mono<ServerResponse> newForm(ServerRequest request) {
Mono<DataBuffer> resultMono = request.formData()
.map(formData -> new LinkedMultiValueMap(formData))
.doOnNext(newFormData -> newFormData.add("status", "success"))
.map(linkedMultiValueMap -> createBody(linkedMultiValueMap));
return ServerResponse.ok().contentType(MediaType.APPLICATION_FORM_URLENCODED)
.body(BodyInserters.fromDataBuffers(resultMono));
}
private DataBuffer createBody(MultiValueMap multiValueMap) {
try {
DefaultDataBufferFactory factory = new DefaultDataBufferFactory();
return factory.wrap(ByteBuffer.wrap(objectMapper.writeValueAsString(multiValueMap).getBytes(StandardCharsets.UTF_8)));
} catch (JsonProcessingException e) {
throw new IllegalArgumentException("incorrect body");
}
}
When using reactor's retry(..) operator WebClient exchange filter functions are not triggered on retry. I understand why, but the issue is when a function (like bellow) generates an authentication token with an expiry time. It might happen, while a request is being "retried" the token expires because the Exchange function is not re-invoked during the retry. Is there a way how to re-generate a token for each retry?
Following AuthClientExchangeFunction generates an authentication token (JWT) with an expiration.
public class AuthClientExchangeFunction implements ExchangeFilterFunction {
private final TokenProvider tokenProvider;
public IntraAuthWebClientExchangeFunction(TokenProvider tokenProvider) {
this.tokenProvider = tokenProvider;
}
#Override
public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
String jwt = tokenProvider.getToken();
return next.exchange(withBearer(request, jwt));
}
private ClientRequest withBearer(ClientRequest request, String jwt){
return ClientRequest.from(request)
.headers(headers -> headers.set(HttpHeaders.AUTHORIZATION, "Bearer "+ jwt))
.build();
}
}
Lets say that a token is valid for 2999 ms -> Each retry request fails due to 401.
WebClient client = WebClient.builder()
.filter(new AuthClientExchangeFunction(tokenProvider))
.build();
client.get()
.uri("/api")
.retrieve()
.bodyToMono(String.class)
.retryBackoff(1, Duration.ofMillis(3000)) ;
Edit
Here is an executable example
#SpringBootTest
#RunWith(SpringRunner.class)
public class RetryApplicationTests {
private static final MockWebServer server = new MockWebServer();
private final RquestCountingFilterFunction requestCounter = new RquestCountingFilterFunction();
#AfterClass
public static void shutdown() throws IOException {
server.shutdown();
}
#Test
public void test() {
server.enqueue(new MockResponse().setResponseCode(500).setBody("{}"));
server.enqueue(new MockResponse().setResponseCode(500).setBody("{}"));
server.enqueue(new MockResponse().setResponseCode(500).setBody("{}"));
server.enqueue(new MockResponse().setResponseCode(200).setBody("{}"));
WebClient webClient = WebClient.builder()
.baseUrl(server.url("/api").toString())
.filter(requestCounter)
.build();
Mono<String> responseMono1 = webClient.get()
.uri("/api")
.retrieve()
.bodyToMono(String.class)
.retryBackoff(3, Duration.ofMillis(1000)) ;
StepVerifier.create(responseMono1).expectNextCount(1).verifyComplete();
assertThat(requestCounter.count()).isEqualTo(4);
}
static class RquestCountingFilterFunction implements ExchangeFilterFunction {
final Logger log = LoggerFactory.getLogger(getClass());
final AtomicInteger counter = new AtomicInteger();
#Override
public Mono<ClientResponse> filter(ClientRequest request, ExchangeFunction next) {
log.info("Sending {} request to {} {}", counter.incrementAndGet(), request.method(), request.url());
return next.exchange(request);
}
int count() {
return counter.get();
}
}
}
output
MockWebServer[44855] starting to accept connections
Sending 1 request to GET http://localhost:44855/api/api
MockWebServer[44855] received request: GET /api/api HTTP/1.1 and responded: HTTP/1.1 500 Server Error
MockWebServer[44855] received request: GET /api/api HTTP/1.1 and responded: HTTP/1.1 500 Server Error
MockWebServer[44855] received request: GET /api/api HTTP/1.1 and responded: HTTP/1.1 500 Server Error
MockWebServer[44855] received request: GET /api/api HTTP/1.1 and responded: HTTP/1.1 200 OK
org.junit.ComparisonFailure:
Expected :4
Actual :1
You need to update your spring-boot version to 2.2.0.RELEASE. retry() will not invoke exchange function in previous version.
I've tested this using a simple code (In Kotlin).
#Component
class AnswerPub {
val webClient = WebClient.builder()
.filter(PrintExchangeFunction())
.baseUrl("https://jsonplaceholder.typicode.com").build()
fun productInfo(): Mono<User> {
return webClient
.get()
.uri("/todos2/1")
.retrieve()
.bodyToMono(User::class.java)
.retry(2) { it is Exception }
}
data class User(
val id: String,
val userId: String,
val title: String,
val completed: Boolean
)
}
class PrintExchangeFunction : ExchangeFilterFunction {
override fun filter(request: ClientRequest, next: ExchangeFunction): Mono<ClientResponse> {
println("Filtered")
return next.exchange(request)
}
}
And the console output looked like:
2019-10-29 09:31:55.912 INFO 12206 --- [ main] o.s.b.web.embedded.netty.NettyWebServer : Netty started on port(s): 8080
2019-10-29 09:31:55.917 INFO 12206 --- [ main] c.e.s.SpringWfDemoApplicationKt : Started SpringWfDemoApplicationKt in 3.19 seconds (JVM running for 4.234)
Filtered
Filtered
Filtered
So in my case, the exchange function is invoked every single time.
I am using webflux Mono (in Spring boot 5) to consume an external API. I am able to get data well when the API response status code is 200, but when the API returns an error I am not able to retrieve the error message from the API. Spring webclient error handler always display the message as
ClientResponse has erroneous status code: 500 Internal Server Error, but when I use PostMan the API returns this JSON response with status code 500.
{
"error": {
"statusCode": 500,
"name": "Error",
"message":"Failed to add object with ID:900 as the object exists",
"stack":"some long message"
}
}
My request using WebClient is as follows
webClient.getWebClient()
.post()
.uri("/api/Card")
.body(BodyInserters.fromObject(cardObject))
.retrieve()
.bodyToMono(String.class)
.doOnSuccess( args -> {
System.out.println(args.toString());
})
.doOnError( e ->{
e.printStackTrace();
System.out.println("Some Error Happend :"+e);
});
My question is, how can I get access to the JSON response when the API returns an Error with status code of 500?
If you want to retrieve the error details:
WebClient webClient = WebClient.builder()
.filter(ExchangeFilterFunction.ofResponseProcessor(clientResponse -> {
if (clientResponse.statusCode().isError()) {
return clientResponse.bodyToMono(ErrorDetails.class)
.flatMap(errorDetails -> Mono.error(new CustomClientException(clientResponse.statusCode(), errorDetails)));
}
return Mono.just(clientResponse);
}))
.build();
with
class CustomClientException extends WebClientException {
private final HttpStatus status;
private final ErrorDetails details;
CustomClientException(HttpStatus status, ErrorDetails details) {
super(status.getReasonPhrase());
this.status = status;
this.details = details;
}
public HttpStatus getStatus() {
return status;
}
public ErrorDetails getDetails() {
return details;
}
}
and with the ErrorDetails class mapping the error body
Per-request variant:
webClient.get()
.exchange()
.map(clientResponse -> {
if (clientResponse.statusCode().isError()) {
return clientResponse.bodyToMono(ErrorDetails.class)
.flatMap(errorDetails -> Mono.error(new CustomClientException(clientResponse.statusCode(), errorDetails)));
}
return clientResponse;
})
Just as #Frischling suggested, I changed my request to look as follows
return webClient.getWebClient()
.post()
.uri("/api/Card")
.body(BodyInserters.fromObject(cardObject))
.exchange()
.flatMap(clientResponse -> {
if (clientResponse.statusCode().is5xxServerError()) {
clientResponse.body((clientHttpResponse, context) -> {
return clientHttpResponse.getBody();
});
return clientResponse.bodyToMono(String.class);
}
else
return clientResponse.bodyToMono(String.class);
});
I also noted that there's a couple of status codes from 1xx to 5xx, which is going to make my error handling easier for different cases
Look at .onErrorMap(), that gives you the exception to look at. Since you might also need the body() of the exchange() to look at, don't use retrieve, but
.exchange().flatMap((ClientResponse) response -> ....);
I am trying to create a web application using spring 5 . It's a micro-service which hit few other micro-services. Response from one service is dependent the other.I am using global exception handing in my application.
Here is my code:
#Override
public Mono<Response> checkAvailablity(Request request) {
Mono<Response> authResponse = userService.authenticateToken(request);
return authResponse.doOnSuccess(t -> {
// if success is returned.
// Want to return this innerResponse
Mono<Response> innerResponse =
httpService.sendRequest(Constant.SER_BOOKING_SERVICE_CHECK_AVAILABILTY,
request.toString(), Response.class);
}).doOnError(t -> {
logger.info("Subscribing mono in Booking service - On Error");
Mono.error(new CustomException(Constant.EX_MODULE_CONNECTION_TIMED_OUT));
});
In case of error I want to throw CustomException and catch it in global exception handler:
#ControllerAdvice
public class ExceptionInterceptor {
public static Logger logger = Logger.getLogger(ExceptionInterceptor.class);
#ExceptionHandler(value = CustomException.class)
#ResponseBody
public Response authenticationFailure(ServerHttpRequest httpRequest, ServerHttpResponse response,
CustomException ex) {
logger.info("CustomException Occured with code => " + ex.getMessage());
return buildErrorResponse(ex.getMessage());
}
Based on the above code I have two problems:
The exception which is thrown in Mono.error() is not captured in global exception handler.
In case of success, response from the inner service should be returned.
Used two methods in mono: flatmap() and onErrorMap()
and updated my checkAvailablity() code:
public Mono<Response> checkAvailablity(Request request) {
Mono<Response> authResponse = userService.authenticateToken(request);
return authResponse.flatmap(t -> {
// Added transform() for success case
Mono<Response> response = httpService.sendRequest(Constant.SER_BOOKING_SERVICE_CHECK_AVAILABILTY,
request.toString(), Response.class);
logger.info("Response from SER_BOOKING_SERVICE_CHECK_AVAILABILTY");
return response;
}).onErrorMap(t -> {
// Added onErrorMap() for failure case & now exception is caught in global exception handler.
throw new CustomException(Constant.EX_MODULE_CONNECTION_TIMED_OUT);
});
}
I want to have centralised logging for requests and responses in my REST API on Spring WebFlux with Kotlin. So far I've tried this approaches
#Bean
fun apiRouter() = router {
(accept(MediaType.APPLICATION_JSON) and "/api").nest {
"/user".nest {
GET("/", userHandler::listUsers)
POST("/{userId}", userHandler::updateUser)
}
}
}.filter { request, next ->
logger.info { "Processing request $request with body ${request.bodyToMono<String>()}" }
next.handle(request).doOnSuccess { logger.info { "Handling with response $it" } }
}
Here request method and path log successfully but the body is Mono, so how should I log it? Should it be the other way around and I have to subscribe on request body Mono and log it in the callback?
Another problem is that ServerResponse interface here doesn't have access to the response body. How can I get it here?
Another approach I've tried is using WebFilter
#Bean
fun loggingFilter(): WebFilter =
WebFilter { exchange, chain ->
val request = exchange.request
logger.info { "Processing request method=${request.method} path=${request.path.pathWithinApplication()} params=[${request.queryParams}] body=[${request.body}]" }
val result = chain.filter(exchange)
logger.info { "Handling with response ${exchange.response}" }
return#WebFilter result
}
Same problem here: request body is Flux and no response body.
Is there a way to access full request and response for logging from some filters? What don't I understand?
This is more or less similar to the situation in Spring MVC.
In Spring MVC, you can use a AbstractRequestLoggingFilter filter and ContentCachingRequestWrapper and/or ContentCachingResponseWrapper. Many tradeoffs here:
if you'd like to access servlet request attributes, you need to actually read and parse the request body
logging the request body means buffering the request body, which can use a significant amount of memory
if you'd like to access the response body, you need to wrap the response and buffer the response body as it's being written, for later retrieval
ContentCaching*Wrapper classes don't exist in WebFlux but you could create similar ones. But keep in mind other points here:
buffering data in memory somehow goes against the reactive stack, since we're trying there to be very efficient with the available resources
you should not tamper with the actual flow of data and flush more/less often than expected, otherwise you'd risk breaking streaming uses cases
at that level, you only have access to DataBuffer instances, which are (roughly) memory-efficient byte arrays. Those belong to buffer pools and are recycled for other exchanges. If those aren't properly retained/released, memory leaks are created (and buffering data for later consumption certainly fits that scenario)
again at that level, it's only bytes and you don't have access to any codec to parse the HTTP body. I'd forget about buffering the content if it's not human-readable in the first place
Other answers to your question:
yes, the WebFilter is probably the best approach
no, you shouldn't subscribe to the request body otherwise you'd consume data that the handler won't be able to read; you can flatMap on the request and buffer data in doOn operators
wrapping the response should give you access to the response body as it's being written; don't forget about memory leaks, though
I didn't find a good way to log request/response bodies, but if you are just interested in meta data then you can do it like follows.
import org.springframework.http.HttpHeaders
import org.springframework.http.HttpStatus
import org.springframework.http.server.reactive.ServerHttpResponse
import org.springframework.stereotype.Component
import org.springframework.web.server.ServerWebExchange
import org.springframework.web.server.WebFilter
import org.springframework.web.server.WebFilterChain
import reactor.core.publisher.Mono
#Component
class LoggingFilter(val requestLogger: RequestLogger, val requestIdFactory: RequestIdFactory) : WebFilter {
val logger = logger()
override fun filter(exchange: ServerWebExchange, chain: WebFilterChain): Mono<Void> {
logger.info(requestLogger.getRequestMessage(exchange))
val filter = chain.filter(exchange)
exchange.response.beforeCommit {
logger.info(requestLogger.getResponseMessage(exchange))
Mono.empty()
}
return filter
}
}
#Component
class RequestLogger {
fun getRequestMessage(exchange: ServerWebExchange): String {
val request = exchange.request
val method = request.method
val path = request.uri.path
val acceptableMediaTypes = request.headers.accept
val contentType = request.headers.contentType
return ">>> $method $path ${HttpHeaders.ACCEPT}: $acceptableMediaTypes ${HttpHeaders.CONTENT_TYPE}: $contentType"
}
fun getResponseMessage(exchange: ServerWebExchange): String {
val request = exchange.request
val response = exchange.response
val method = request.method
val path = request.uri.path
val statusCode = getStatus(response)
val contentType = response.headers.contentType
return "<<< $method $path HTTP${statusCode.value()} ${statusCode.reasonPhrase} ${HttpHeaders.CONTENT_TYPE}: $contentType"
}
private fun getStatus(response: ServerHttpResponse): HttpStatus =
try {
response.statusCode
} catch (ex: Exception) {
HttpStatus.CONTINUE
}
}
This is what I came up with for java.
public class RequestResponseLoggingFilter implements WebFilter {
#Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
ServerHttpRequest httpRequest = exchange.getRequest();
final String httpUrl = httpRequest.getURI().toString();
ServerHttpRequestDecorator loggingServerHttpRequestDecorator = new ServerHttpRequestDecorator(exchange.getRequest()) {
String requestBody = "";
#Override
public Flux<DataBuffer> getBody() {
return super.getBody().doOnNext(dataBuffer -> {
try (ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream()) {
Channels.newChannel(byteArrayOutputStream).write(dataBuffer.asByteBuffer().asReadOnlyBuffer());
requestBody = IOUtils.toString(byteArrayOutputStream.toByteArray(), "UTF-8");
commonLogger.info(LogMessage.builder()
.step(httpUrl)
.message("log incoming http request")
.stringPayload(requestBody)
.build());
} catch (IOException e) {
commonLogger.error(LogMessage.builder()
.step("log incoming request for " + httpUrl)
.message("fail to log incoming http request")
.errorType("IO exception")
.stringPayload(requestBody)
.build(), e);
}
});
}
};
ServerHttpResponseDecorator loggingServerHttpResponseDecorator = new ServerHttpResponseDecorator(exchange.getResponse()) {
String responseBody = "";
#Override
public Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {
Mono<DataBuffer> buffer = Mono.from(body);
return super.writeWith(buffer.doOnNext(dataBuffer -> {
try (ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream()) {
Channels.newChannel(byteArrayOutputStream).write(dataBuffer.asByteBuffer().asReadOnlyBuffer());
responseBody = IOUtils.toString(byteArrayOutputStream.toByteArray(), "UTF-8");
commonLogger.info(LogMessage.builder()
.step("log outgoing response for " + httpUrl)
.message("incoming http request")
.stringPayload(responseBody)
.build());
} catch (Exception e) {
commonLogger.error(LogMessage.builder()
.step("log outgoing response for " + httpUrl)
.message("fail to log http response")
.errorType("IO exception")
.stringPayload(responseBody)
.build(), e);
}
}));
}
};
return chain.filter(exchange.mutate().request(loggingServerHttpRequestDecorator).response(loggingServerHttpResponseDecorator).build());
}
}
You can actually enable DEBUG logging for Netty and Reactor-Netty related to see full picture of what's happening. You could play with the below and see what you want and don't. That was the best I could.
reactor.ipc.netty.channel.ChannelOperationsHandler: DEBUG
reactor.ipc.netty.http.server.HttpServer: DEBUG
reactor.ipc.netty.http.client: DEBUG
io.reactivex.netty.protocol.http.client: DEBUG
io.netty.handler: DEBUG
io.netty.handler.proxy.HttpProxyHandler: DEBUG
io.netty.handler.proxy.ProxyHandler: DEBUG
org.springframework.web.reactive.function.client: DEBUG
reactor.ipc.netty.channel: DEBUG
Since Spring Boot 2.2.x, Spring Webflux supports Kotlin coroutines. With coroutines, you can have the advantages of non-blocking calls without having to handle Mono and Flux wrapped objects. It adds extensions to ServerRequest and ServerResponse, adding methods like ServerRequest#awaitBody() and ServerResponse.BodyBuilder.bodyValueAndAwait(body: Any). So you could rewrite you code like this:
#Bean
fun apiRouter() = coRouter {
(accept(MediaType.APPLICATION_JSON) and "/api").nest {
"/user".nest {
/* the handler methods now use ServerRequest and ServerResponse directly
you just need to add suspend before your function declaration:
suspend fun listUsers(ServerRequest req, ServerResponse res) */
GET("/", userHandler::listUsers)
POST("/{userId}", userHandler::updateUser)
}
}
// this filter will be applied to all routes built by this coRouter
filter { request, next ->
// using non-blocking request.awayBody<T>()
logger.info("Processing $request with body ${request.awaitBody<String>()}")
val res = next(request)
logger.info("Handling with Content-Type ${res.headers().contentType} and status code ${res.rawStatusCode()}")
res
}
}
In order to create a WebFilter Bean with coRoutines, I think you can use this CoroutineWebFilter interface (I haven't tested it, I don't know if it works).
I am pretty new to Spring WebFlux, and I don't know how to do it in Kotlin, but should be the same as in Java using WebFilter:
public class PayloadLoggingWebFilter implements WebFilter {
public static final ByteArrayOutputStream EMPTY_BYTE_ARRAY_OUTPUT_STREAM = new ByteArrayOutputStream(0);
private final Logger logger;
private final boolean encodeBytes;
public PayloadLoggingWebFilter(Logger logger) {
this(logger, false);
}
public PayloadLoggingWebFilter(Logger logger, boolean encodeBytes) {
this.logger = logger;
this.encodeBytes = encodeBytes;
}
#Override
public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
if (logger.isInfoEnabled()) {
return chain.filter(decorate(exchange));
} else {
return chain.filter(exchange);
}
}
private ServerWebExchange decorate(ServerWebExchange exchange) {
final ServerHttpRequest decorated = new ServerHttpRequestDecorator(exchange.getRequest()) {
#Override
public Flux<DataBuffer> getBody() {
if (logger.isDebugEnabled()) {
final ByteArrayOutputStream baos = new ByteArrayOutputStream();
return super.getBody().map(dataBuffer -> {
try {
Channels.newChannel(baos).write(dataBuffer.asByteBuffer().asReadOnlyBuffer());
} catch (IOException e) {
logger.error("Unable to log input request due to an error", e);
}
return dataBuffer;
}).doOnComplete(() -> flushLog(baos));
} else {
return super.getBody().doOnComplete(() -> flushLog(EMPTY_BYTE_ARRAY_OUTPUT_STREAM));
}
}
};
return new ServerWebExchangeDecorator(exchange) {
#Override
public ServerHttpRequest getRequest() {
return decorated;
}
private void flushLog(ByteArrayOutputStream baos) {
ServerHttpRequest request = super.getRequest();
if (logger.isInfoEnabled()) {
StringBuffer data = new StringBuffer();
data.append('[').append(request.getMethodValue())
.append("] '").append(String.valueOf(request.getURI()))
.append("' from ")
.append(
Optional.ofNullable(request.getRemoteAddress())
.map(addr -> addr.getHostString())
.orElse("null")
);
if (logger.isDebugEnabled()) {
data.append(" with payload [\n");
if (encodeBytes) {
data.append(new HexBinaryAdapter().marshal(baos.toByteArray()));
} else {
data.append(baos.toString());
}
data.append("\n]");
logger.debug(data.toString());
} else {
logger.info(data.toString());
}
}
}
};
}
}
Here some tests on this: github
I think this is what Brian Clozel (#brian-clozel) meant.
Here is the GitHub Repo with complete implementation to log both request and response body along with http headers for webflux/java based application...
What Brian said. In addition, logging request/response bodies don't make sense for reactive streaming. If you imagine the data flowing through a pipe as a stream, you don't have the full content at any time unless you buffer it, which defeats the whole point. For small request/response, you can get away with buffering, but then why use the reactive model (other than to impress your coworkers :-) )?
The only reason for logging request/response that I could conjure up is debugging, but with the reactive programming model, debugging method has to be modified too. Project Reactor doc has an excellent section on debugging that you can refer to: http://projectreactor.io/docs/core/snapshot/reference/#debugging
Assuming we are dealing with a simple JSON or XML response, if debug level for corresponding loggers is not sufficient for some reason, one can use string representation before transforming it to object:
Mono<Response> mono = WebClient.create()
.post()
.body(Mono.just(request), Request.class)
.retrieve()
.bodyToMono(String.class)
.doOnNext(this::sideEffectWithResponseAsString)
.map(this::transformToResponse);
the following are the side-effect and transformation methods:
private void sideEffectWithResponseAsString(String response) { ... }
private Response transformToResponse(String response) { /*use Jackson or JAXB*/ }
If your using controller instead of handler best way is aop with annotating you controller class with #Log annotation.And FYI this takes plain json object as request not mono.
#Target(AnnotationTarget.FUNCTION)
#Retention(AnnotationRetention.RUNTIME)
annotation class Log
#Aspect
#Component
class LogAspect {
companion object {
val log = KLogging().logger
}
#Around("#annotation(Log)")
#Throws(Throwable::class)
fun logAround(joinPoint: ProceedingJoinPoint): Any? {
val start = System.currentTimeMillis()
val result = joinPoint.proceed()
return if (result is Mono<*>) result.doOnSuccess(getConsumer(joinPoint, start)) else result
}
fun getConsumer(joinPoint: ProceedingJoinPoint, start: Long): Consumer<Any>? {
return Consumer {
var response = ""
if (Objects.nonNull(it)) response = it.toString()
log.info(
"Enter: {}.{}() with argument[s] = {}",
joinPoint.signature.declaringTypeName, joinPoint.signature.name,
joinPoint.args
)
log.info(
"Exit: {}.{}() had arguments = {}, with result = {}, Execution time = {} ms",
joinPoint.signature.declaringTypeName, joinPoint.signature.name,
joinPoint.args[0],
response, System.currentTimeMillis() - start
)
}
}
}
I think the appropriate thing to do here is to write the contents of each request to a file in an asynchronous manner (java.nio) and set up an interval that reads those request body files asynchrolusly and writes them to the log in a memory usage aware manner (atleast one file at a time but up too 100 mb at a time) and after logging them removes the files from disk.
Ivan Lymar's answer but in Kotlin:
import org.apache.commons.io.IOUtils
import org.reactivestreams.Publisher
import org.springframework.core.io.buffer.DataBuffer
import org.springframework.http.server.reactive.ServerHttpRequestDecorator
import org.springframework.http.server.reactive.ServerHttpResponseDecorator
import org.springframework.stereotype.Component
import org.springframework.web.server.ServerWebExchange
import org.springframework.web.server.WebFilter
import org.springframework.web.server.WebFilterChain
import reactor.core.publisher.Flux
import reactor.core.publisher.Mono
import java.io.ByteArrayOutputStream
import java.io.IOException
import java.nio.channels.Channels
#Component
class LoggingWebFilter : WebFilter {
override fun filter(exchange: ServerWebExchange, chain: WebFilterChain): Mono<Void> {
val httpRequest = exchange.request
val httpUrl = httpRequest.uri.toString()
val loggingServerHttpRequestDecorator: ServerHttpRequestDecorator =
object : ServerHttpRequestDecorator(exchange.request) {
var requestBody = ""
override fun getBody(): Flux<DataBuffer> {
return super.getBody().doOnNext { dataBuffer: DataBuffer ->
try {
ByteArrayOutputStream().use { byteArrayOutputStream ->
Channels.newChannel(byteArrayOutputStream)
.write(dataBuffer.asByteBuffer().asReadOnlyBuffer())
requestBody =
IOUtils.toString(
byteArrayOutputStream.toByteArray(),
"UTF-8"
)
log.info(
"Logging Request Filter: {} {}",
httpUrl,
requestBody
)
}
} catch (e: IOException) {
log.error(
"Logging Request Filter Error: {} {}",
httpUrl,
requestBody,
e
)
}
}
}
}
val loggingServerHttpResponseDecorator: ServerHttpResponseDecorator =
object : ServerHttpResponseDecorator(exchange.response) {
var responseBody = ""
override fun writeWith(body: Publisher<out DataBuffer>): Mono<Void> {
val buffer: Mono<DataBuffer> = Mono.from(body)
return super.writeWith(
buffer.doOnNext { dataBuffer: DataBuffer ->
try {
ByteArrayOutputStream().use { byteArrayOutputStream ->
Channels.newChannel(byteArrayOutputStream)
.write(
dataBuffer
.asByteBuffer()
.asReadOnlyBuffer()
)
responseBody = IOUtils.toString(
byteArrayOutputStream.toByteArray(),
"UTF-8"
)
log.info(
"Logging Response Filter: {} {}",
httpUrl,
responseBody
)
}
} catch (e: Exception) {
log.error(
"Logging Response Filter Error: {} {}",
httpUrl,
responseBody,
e
)
}
}
)
}
}
return chain.filter(
exchange.mutate().request(loggingServerHttpRequestDecorator)
.response(loggingServerHttpResponseDecorator)
.build()
)
}
}