I make a request to the server, but there is no body in the response.
Accordingly, the return value type of response is Unit.
suspend fun foo(
url: String,
id: Long
) {
val requestUrl = "$url/Subscriptions?id=${id}"
val response = httpApiClient.delete<Unit>(requestUrl) {
headers {
append(HttpHeaders.Authorization, createRequestToken(token))
}
}
return response
}
How in this case to receive the code of the executed request?
HttpResponseValidator {
validateResponse { response ->
TODO()
}
}
using a similar construction and throwing an error, for example, is not an option, since one http client is used for several requests, and making a new http client for one request is strange. is there any other way out?
You can specify the HttpResponse type as a type argument instead of Unit to get an object that allows you to access the status property (HTTP status code), headers, to receive the body of a response, etc. Here is an example:
import io.ktor.client.HttpClient
import io.ktor.client.engine.apache.*
import io.ktor.client.request.*
import io.ktor.client.statement.*
suspend fun main() {
val client = HttpClient(Apache)
val response = client.get<HttpResponse>("https://httpbin.org/get")
// the response body isn't received yet
println(response.status)
}
Related
I have been trying to get Json data from dummyjson and place them into an Array in the ktor server. But it just won't work.
Application.kt:
fun main() {
embeddedServer(Netty, port = 8080, host = "0.0.0.0") {
install(ContentNegotiation) {
gson {
setDateFormat(DateFormat.LONG)
setPrettyPrinting()
}
}
val client = HttpClient(CIO)
val products: Array<Product> = client.get("https://dummyjson.com/products").body()
configureRouting()
}.start(wait = true)
}
I could create the client but I am not allowed to use the get method because it says Suspend function 'get' should be called only from a coroutine or another suspend function.
Then, in configureRouting.kt I defined the client and used the get method. It works and returns the String to the client.
fun Application.configureRouting() {
val client = HttpClient(CIO)
routing {
get("/get-all-products"){
val product: String = client.get("https://dummyjson.com/products").body()
call.respond(product)
}
}
However, what I want to achieve is without the client's request, the server can automatically load all the JSON file from dummyjson, and place it in a list. But it just keep giving me the same error if I place this get method outside the routing.
We are using Spring Cloud Gateway in order to route requests to multiple underlying services. The calls to these underlying services will be sequential and potentially feed into one another (response from one being used in the request for the next). We have a working solution for when we need to make those requests sequentially BEFORE the main request, but after the main request we are having problems with feeding the response of one proxy request into the request of the next.
The way we have planned on feeding the response from one request to the next is by making the request using a WebClient in the GatewayFilter and storing the response string in the exchange's attribute store. Then during the next proxy request we supply an attribute name to optionally pull the request body from. This works well when using "pre" filters, because the first proxy request is built, executed and response cached before the second request is built and executed, so the chain of attributes works as expected. The problem comes when working with "post" filters. In the post proxy, the web client requests are all built before the subsequent request has finished. So the attribute store never has the response from the previous request, meaning the next request doesn't work as intended because it doesn't have a valid request body.
My understanding was that calling chain.filter(exchange).then(Mono.fromRunnable{ ... }) would cause the .then logic to execute only after the prior filters had fully completed. This does not seem to be the case. In other filter types like logging, response manipulation, etc the post filters execute in the correct order, but when creating a WebClient they don't seem to.
Does anyone have any ideas on how this desired behavior might be achievable?
Pre-Proxy Filter Code(Working):
class PreProxyGatewayFilterFactory: AbstractGatewayFilterFactory<PreProxyGatewayFilterFactory.Params>(Params::class.java) {
override fun apply(params: Params): GatewayFilter {
return OrderedGatewayFilter(
{ exchange, chain ->
ServerWebExchangeUtils.cacheRequestBody(exchange){
val cachedExchange = exchange.mutate().request(it).build()
executeRequest(cachedExchange, params)
.map { response ->
val body = response.body.toString()
cacheResponse(
response.body.toString(),
params.cachedResponseBodyAttributeName,
cachedExchange
)
}
.flatMap(chain::filter)
}
}, params.order)
}
private fun cacheResponse(response: String, attributeName: String?, exchange: ServerWebExchange): ServerWebExchange{
if(!attributeName.isNullOrBlank()){
exchange.attributes[attributeName] = response
}
return exchange
}
private fun executeRequest(exchange: ServerWebExchange, params: Params): Mono<ResponseEntity<String>>{
val request = when(exchange.request.method){
HttpMethod.PUT -> WebClient.create().put().uri(params.proxyPath).body(createProxyRequestBody(exchange, params.cachedRequestBodyAttributeName))
HttpMethod.POST -> WebClient.create().post().uri(params.proxyPath).body(createProxyRequestBody(exchange, params.cachedRequestBodyAttributeName))
HttpMethod.GET -> WebClient.create().get().uri(params.proxyPath)
HttpMethod.DELETE -> WebClient.create().delete().uri(params.proxyPath)
else -> throw Exception("Invalid request method passed in to the proxy filter")
}
return request.headers { headers ->
headers.addAll(exchange.request.headers)
headers.remove(CONTENT_LENGTH)
}
.exchange()
.flatMap{ response ->
response.toEntity(String::class.java)
}
}
private fun createProxyRequestBody(exchange: ServerWebExchange, attributeName: String?): BodyInserter<out Flux<out Any>, ReactiveHttpOutputMessage> {
val cachedBody = attributeName?.let { attrName ->
exchange.getAttributeOrDefault<String>(attrName, "null")
} ?: "null"
return if(cachedBody != "null"){
BodyInserters.fromPublisher(Flux.just(cachedBody), String::class.java)
} else {
BodyInserters.fromDataBuffers(exchange.request.body)
}
}
data class Params(
val proxyPath: String = "",
val cachedRequestBodyAttributeName: String? = null,
val cachedResponseBodyAttributeName: String? = null,
val order: Int = 0
)
}
Post-Proxy Filter Code (Not Working)
class PostProxyGatewayFilterFactory: AbstractGatewayFilterFactory<PostProxyGatewayFilterFactory.Params>(Params::class.java) {
override fun apply(params: Params): GatewayFilter {
return OrderedGatewayFilter(
{ exchange, chain ->
ServerWebExchangeUtils.cacheRequestBody(exchange){
val cachedExchange = exchange.mutate().request(it).build()
//Currently using a cached body does not work in post proxy
chain.filter(cachedExchange).then( Mono.fromRunnable{
executeRequest(cachedExchange, params)
.map { response ->
cacheResponse(
response.body.toString(),
params.cachedResponseBodyAttributeName,
cachedExchange
)
}
.flatMap {
Mono.empty<Void>()
}
})
}
}, params.order)
}
private fun cacheResponse(response: String, attributeName: String?, exchange: ServerWebExchange): ServerWebExchange{
if(!attributeName.isNullOrBlank()){
exchange.attributes[attributeName] = response
}
return exchange
}
private fun executeRequest(exchange: ServerWebExchange, params: Params): Mono<ResponseEntity<String>>{
val request = when(exchange.request.method){
HttpMethod.PUT -> WebClient.create().put().uri(params.proxyPath).body(createProxyRequestBody(exchange, params.cachedRequestBodyAttributeName))
HttpMethod.POST -> WebClient.create().post().uri(params.proxyPath).body(createProxyRequestBody(exchange, params.cachedRequestBodyAttributeName))
HttpMethod.GET -> WebClient.create().get().uri(params.proxyPath)
HttpMethod.DELETE -> WebClient.create().delete().uri(params.proxyPath)
else -> throw Exception("Invalid request method passed in to the proxy filter")
}
return request.headers { headers ->
headers.addAll(exchange.request.headers)
headers.remove(CONTENT_LENGTH)
}
.exchange()
.flatMap{ response ->
response.toEntity(String::class.java)
}
}
private fun createProxyRequestBody(exchange: ServerWebExchange, attributeName: String?): BodyInserter<out Flux<out Any>, ReactiveHttpOutputMessage> {
val cachedBody = attributeName?.let { attrName ->
exchange.getAttributeOrDefault<String>(attrName, "null")
} ?: "null"
return if(cachedBody != "null"){
BodyInserters.fromPublisher(Flux.just(cachedBody), String::class.java)
} else {
BodyInserters.fromDataBuffers(exchange.request.body)
}
}
data class Params(
val proxyPath: String = "",
val cachedRequestBodyAttributeName: String? = null,
val cachedResponseBodyAttributeName: String? = null,
val order: Int = 0
)
}
Was finally able to get to a working solution for the post filter proxy pulling it's request body from the attributes. It was a relatively straightforward fix that I just couldn't find the answer to. Instead of using chain.filter(exchange).then(Mono.fromRunnable { ...execute proxy request...}) I just needed to use chain.filter(exchange).then(Mono.defer { ...execute proxy request...}).
How do I monitor request progress in Ktor http client?
For example: I have request like this:
val response = HttpClient().get<String>("https://stackoverflow.com/")
and I want to monitor request progress with progress bar like this:
fun progress(downloaded: Long, contentLength: Long) {
// Update progress bar or whatever
}
How do I set progress() to be called by HttpClient?
edit: This is Kotlin Multiplatform project. Relevant dependencies are:
implementation 'io.ktor:ktor-client-core:1.2.5'
implementation 'io.ktor:ktor-client-cio:1.2.5'
Starting with Ktor 1.6.0, you can react to download progress change using the onDownload extension function exposed by HttpRequestBuilder:
val channel = get<ByteReadChannel>("https://ktor.io/") {
onDownload { bytesSentTotal, contentLength ->
println("Received $bytesSentTotal bytes from $contentLength")
}
}
There is also the onUpload function that can be used to display upload progress:
onUpload { bytesSentTotal, contentLength ->
println("Sent $bytesSentTotal bytes from $contentLength")
}
Here are runnable examples from the Ktor documentation:
download-file
upload-file
How to emit the download progress into a Flow?
I want to observe the download progress by a Flow, so I write a function like this:
suspend fun downloadFile(file: File, url: String): Flow<Int>{
val client = HttpClient(Android)
return flow{
val httpResponse: HttpResponse = client.get(url) {
onDownload { bytesSentTotal, contentLength ->
val progress = (bytesSentTotal * 100f / contentLength).roundToInt()
emit(progress)
}
}
val responseBody: ByteArray = httpResponse.receive()
file.writeBytes(responseBody)
}
}
but the onDownload will be called only once. If I remove the emit(progress) it will work.
#andrey-aksyonov
Getting Response{protocol=http/1.1, code=404, message=Not Found, url=https://test.test.com/service/one}
The url is correct as postman works fine.
I have tried looking into this error but most things come back with URL was in correct. and the error itself is vague.
code that starts it. the builder is a json string that is valid. I have tested it in postman.
CoroutineScope(Dispatchers.Default).launch {
val call = submitService.submitCarton(builder.toString())
Log.d("submit", "begining")
withContext(Dispatchers.Main) {
if (call.isSuccessful) {
Log.d("submit",call.body() as String)
} else {
Log.d("submit", "else....")
}
}
}
service factory:
fun makeSubmitService() : SubmitService{
val url = "https://test.test.com/service/"
return Retrofit.Builder().baseUrl(url)
.client(okHttpClient).addConverterFactory(GsonConverterFactory.create())
.build().create(SubmitService::class.java)
}
interface:
interface SubmitService {
#POST("one")
suspend fun submitCarton(#Body json: String): Response<myModel>
}
Expected results are a json response however I am not getting that far.
edit: I created a okhttpclient and did a request manual and I get a message 200 ok.
code for my test
val JSON = MediaType.parse("application/json; charset=utf-8")
val client = OkHttpClient()
val body = "some json"
val requestBody = RequestBody.create(JSON, body)
val request = Request.Builder()
.url("https://test.test.com/service/one")
.post(requestBody)
.build()
client.newCall(request).enqueue(object : Callback {
override fun onFailure(request: Request, e: IOException) {
Log.e("test", e.toString())
}
#Throws(IOException::class)
override fun onResponse(response: Response) {
Log.d("test", response.toString())
}
})
Solved it myself.
Issue was dumb, retrofit2 was giving 404 even though the web service was returning a error message.
added
implementation 'com.squareup.okhttp3:logging-interceptor:3.12.1'
private val interceptor = HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY)
private val okHttpClient = OkHttpClient().newBuilder()
.connectTimeout(1, TimeUnit.MINUTES)
.readTimeout(30, TimeUnit.SECONDS)
.writeTimeout(20, TimeUnit.SECONDS)
.addInterceptor(interceptor)
.build()
found out retrofit was sending a very unformatted string
"{ \"all my json filled with \" }"
instead of
{ json }
fixed it by adding
.addConverterFactory(ScalarsConverterFactory.create())
to my service factory
for anyone wondering why I am basically creating the json as a string instead of using a JSON object is because the service I talk to really really wants it to be in a very specific order which JSON just don't care about it however it wants it to look like JSON as well...
Im trying to call a service via POST that sends an e-mail to the user, the body always return empty, I have to deal with the response code.
e.g. 204 = success.
Im trying to deal this way, but im not succeeding
Service:
#POST("xxxxxx")
fun resendBankSlip(#Path("userId") userId: Int): Deferred<Response>
ViewModel:
scope.launch {
try {
_loading.value = true
val response = repository.sendEmail(userId)
if (!response.isSuccessful) {
_error.value = R.string.generic_error_message
}
} catch (e: Throwable) {
_error.value = R.string.generic_error_message
} finally {
_loading.value = false
}
}
The error happens on val response = repository.sendEmail(userId)
Exception:
java.lang.IllegalArgumentException: 'okhttp3.Response' is not a valid response body type. Did you mean ResponseBody?
for method EmailService.sendEmail
Any idea?
You probably confused okhttp3.Response with retrofit.Response. Try to use retrofit2.Response wrapper in API response like that:
#POST("xxxxxx")
fun resendBankSlip(#Path("userId") userId: Int): Deferred<retrofit2.Response<Unit>>
After that you can easily get response code via response.code().
Also note that I passed Unit as Response's type argument because you don't need the body. In other cases you should pass an actual type of response body.