We are using the new gcp cloud functions using Java / Kotlin.
As in the current reference implementations, we are returning org.springframework.messaging.support.GenericMessage objects.
So our code looks like this (Kotlin):
fun generatePdfInBase64(message: Message<Map<String, Any>>): Message<*> {
val document = process(message)
val encoded = Base64.getEncoder().encodeToString(document.document)
return GenericMessage(encoded)
}
We were not able to find any way to include a custom http response code to our message, e.g. 201 or something. The function only responds 200 in case of no exception or 500.
Does someone know of a way to do this?
Best wishes
Andy
As it is mentioned at the official documentation, the HttpResponse class has a method called setStatusCode where you are able to set the number of the status as your convenience
For example:
switch (request.getMethod()) {
case "GET":
response.setStatusCode(HttpURLConnection.HTTP_OK);
writer.write("Hello world!");
break;
On the other hand the constructor of the GenericMessage receives as parameter a payload, therefore I think you can create a string with a json format and use the constructor for create your GenericMessage instance with the status response you need.
If you want to know more about the statuds codes take a look at this document.
Related
Our test automation needs to interact with kafka and we are looking at how we can achieve this with karate.
We have a java class which reads from kafka and puts records in an internal list. We then ask for these records from karate, filter out all messages from background traffic, and return the first message that matches our filter.
So our consumer looks like this (simplified):
// consume.js
function(bootstrapServers, topic, filter, timeout, interval) {
var KafkaLib = Java.type('kafka.KafkaLib')
var records = KafkaLib.getRecords(bootstrapServers, topic)
for (record_id in records) {
// TODO here we want to convert record to a json (and later xml for xml records) so that
// we can access them as 'native' karate data types and use notation like: cat.cat.scores.score[1]
var record = records[record_id]
if (filter(record)) {
karate.log("Record matched: " + record)
return record
}
}
throw "No records found matching the filter: " + filter
}
Records can be json, xml, or plain text, but looking in the json case now.
In this case given that in kafka there is a message like this:
{"correlationId":"b3e6bbc7-e5a6-4b2a-a8f9-a0ddf435de67","text":"Hello world"}
This is loaded as a string in the record variable above.
We want to convert this to json so that a filter like this would work:
* def uuid = java.util.UUID.randomUUID() + ''
# This is what we are publishing to kafka
* def payload = ({ correlationId: uuid, text: "Hello world" })
* def filter = function(m) { return m.correlationId == uuid }
Is there a way to convert a string to a native karate variable in javascript? Might have missed it looking at https://intuit.github.io/karate/#the-karate-object. By the way var jsonRecord = karate.toJson(record) did not work and jsonRecord.uuid was undefined.
Edit: I have made an example of what I am trying to achieve here:
https://github.com/KostasKgr/karate-issues/blob/java_json_interop/src/test/java/examples/consumption/consumption.feature
Many thanks
Sometime ago I had put together a something that could be used to test Kafka from within Karate. Pls see if https://github.com/Sdaas/karate-kafka helps. Happy to enhance / improve if it helps you.
Can you try,
* json payload = { correlationId: uuid, text: "Hello world" }
ref : Type Conversion
for type conversion within javascript ideally karate.toMap(object) or karate.toJson(object) should.
rather than wrapping up everything into one JS function, I would suggest keeping the record invoking part outside the JS and let karate cast it.
* json records = Java.type('kafka.KafkaLib').getRecords(bootstrapServers, topic)
* consume(records, filter, timeout, interval)
As mentioned in the comments of another answer, there is now an enhancement ticket on karate to achieve what was discussed in this thread, see https://github.com/intuit/karate/issues/1202
Until that is in place, I managed to get most of what I wanted concerning JSON by parsing string to json in Java and returning that to karate.
Map<String,Object> result = new ObjectMapper().readValue(record, HashMap.class);
Not sure if the same can be worked around for xml
You can see the workaround in action here:
https://github.com/KostasKgr/karate-issues/blob/java_json_interop_v2/src/test/java/examples/consumption/consumption.feature
Because of Karate's support for Java inter-op you can easily write some "glue" code to connect your existing Kafka systems to Karate test-suites, see the first link below.
Here are a few references:
how to use Java inter-op to listen and wait for events: https://twitter.com/KarateDSL/status/1417023536082812935
the Karate ActiveMQ example: https://github.com/intuit/karate/tree/master/karate-netty#consumer-provider-example
Walmart Labs blog post (Kafka specific): https://medium.com/walmartglobaltech/kafka-automation-using-karate-6a129cfdc210
Karate Kafka (3rd party project / example): https://github.com/Sdaas/karate-kafka
I have parameter classes with the #Searializable annotation:
#Serializable
data class ShowPostURL(
val date: String,
val titleSlug: String,
override val redirectTo: String? = null
)
and no matter what I do call.receive() won't work. I'm getting HTTP 415 errors and Ktor doesn't log anything. I've added the serialization support as well:
install(ContentNegotiation) {
json()
}
How do I fix this? This is how I'm trying to use it:
accept(ContentType.Any) {
get("/foo/{date}/{titleSlug}") {
val input = call.receive(ShowPostURL::class)
call.respondText("foo")
}
}
If I do a trace I can see that my route is matched, but it can't receive the parameters. Is this json() setup is supposed to work when I'm deserializing from url parameters like this?
Firstly, ContentNegotiation feature works only for receiving custom objects from the payload of POST, PUT and PATCH requests:
POST, PUT and PATCH requests have an associated request body (the payload). That payload is usually encoded.
In order to receive custom objects from the payload, you have to use the ContentNegotiation feature. This is useful for example to receive and send JSON payloads in REST APIs.
When receiving, the Content-Type of the request will be used to determine which ContentConverter will be used to process that request
Secondly, there are three out of the box ContentConverter available:
GsonConverter, JacksonConverter and SerializationConverter.
Each of these converters has its own configuration function: gson, jackson and serialization respectively. You use json configuration function which is most likely is not appropriate for the configuration of ContentNegotiation.
To solve your problem you can access URL parameters by referring them with call.parameters and manually create ShowPostURL object. Then serialize it with the kotlinx.serialization framework if needed.
Also, you can write your own ContentConverter to implement custom logic for receiving typed objects.
I am following this guide to build my controllers. I do the following.
This is my controller:
// GET api/sth/{sthId}/isValid
[HttpGet("{sthId: int}/isValid")]
[ProducesResponseType(StatusCodes.Status200OK)]
[MyAuthorizeFilter]
public ActionResult<bool> Whatever(int sthId)
{
return this.myService.Whatever(sthId);
}
Theoretically, this should be converted to an Ok() ActionResult. However, If I write the following unit test:
[Fact]
public void Whatever()
{
this.myServiceMock.Setup(x => x.Whatever(It.IsAny<int>())).Returns(true);
-> I DEBUG HERE -> var result = this.myController.Whatever(1);
Assert.IsType<OkObjectResult>(result);
Assert.True((bool)result.Value);
}
I see that my result is an ActionResult<bool> indeed, whose Value is true as expected, but result.Result is null. So: no Ok action result whatsoever.
What am I missing? Do I have to write explicitly the return Ok() to get it? With the sentence
Implicit cast operators support the conversion of both T and ActionResult to ActionResult<T>. T converts to ObjectResult, which means return new ObjectResult(T); is simplified to return T;.
in the documentation I thought it was not necessary...?
The ActionResult<TValue> class:
wraps either an[sic] TValue instance or an ActionResult.
See also the source, its constructors assign either Value or Result, never both.
The MVC pipeline will assign a success status code to the response if no status code was explicitly set. But I can't find documentation for that claim.
This means the response as obtained in this test won't have a status code or OkActionResult anywhere. You can convert it to an ObjectResult, but that won't have a status code.
If you use something like swagger you will indeed get an OK from the server.
This happens to you because you dont perform an http request you simple call a method(your controller method) and you get a return type. You dont create a web server or something so no http status code is generated by .net core.
If you want to get status codes you should write test using http requests. Generally you could look up something like postman to perform your testing.
I have a java adapter (JAX-RS) that returns a POJO, one of the attributes is called validateUser and is a boolean value. I want to get the value of this boolean when called from main.js
It should work like this (main.js):
onGetLoginSuccess function (response)
busy.hide ();
alert ("validate:" + response ["validateUser"]);
As I can get the value in the variable response, the validateUser attribute my POJO.
Thank you for your attention
You can use alert(response.responseJSON.validateUser);
In general to examine the structure of "response" you could do something like: alert(JSON.stringify(response)); It could help you to understand which fields are available and how can you find this validateUser.
It is also important to make sure that your JAX-RS adapter returns JSON content type. Make sure that you have the annotation: #Produces("applicaion/json") in your JAX-RS method that returns this POJO
I am fairly new to Scala and I'm working on an application (library) which is a client to a 3rd-party service (I'm not able to modify the server side and it uses custom binary protocol). I use Netty for networking.
I want to design an API which should allow users to:
Send requests to the server
Send requests to the server and get the response asynchronously
Subscribe to events triggered by the server (having multiple asynchronous event handlers which should be able to send requests as well)
I am not sure how should I design it. Exploring Scala, I stumble upon a bunch of information about Actor model, but I am not sure if it can be applied there and if it can, how.
I'd like to get some recommendations on the way I should take.
In general, the Scala-ish way to expose asynchronous functionality to user code is to return a scala.concurrent.Future[T].
If you're going the actor route, you might consider encapsulating the binary communication within the context of a single actor class. You can scale the instances of this proxy actor using Akka's router support, and you could produce response futures easily using the ask pattern. There are a few nice libraries (Spray, Play Framework) that make wrapping e.g. a RESTful or even WebSocket layer over Akka almost trivial.
A nice model for the pub-sub functionality might be to define a Publisher trait that you can mix in to some actor subclasses. This could define some state to keep track of subscribers, handle Subscribe and Unsubscribe messages, and provide some sort of convenient method for broadcasting messages:
/**
* Sends a copy of the supplied event object to every subscriber of
* the event object class and superclasses.
*/
protected[this] def publish[T](event: T) {
for (subscriber <- subscribersFor(event)) subscriber ! event
}
These are just some ideas based on doing something similar in some recent projects. Feel free to elaborate on your use case if you need more specific direction. Also, the Akka user list is a great resource for general questions like this, if indeed you're interested in exploring actors in Scala.
Observables
This looks like a good example for the Obesrvable pattern. This pattern comes from the Reactive Extensions of .NET, but is also available for Java and Scala. The library is provided by Netflix and has a really good quality.
This pattern has a good theoretical foundation --- it is the dual to the iterator in the category theoretical sense. But more important, it has a lot of practical ideas in it. Especially it handles time very good, e.g. you can limit the event rate you want to get.
With an observable you can process events on avery high level. In .NET it looks a lot like an SQL query. You can register for certain events ("FROM"), filter them ("WHERE") and finally process them ("SELECT"). In Scala you can use standard monadic API (map, filter, flatMap) and of course "for expressions".
An example can look like
stackoverflowQuestions.filter(_.tag == "Scala").map(_.subject).throttleLast(1 second).subscribe(println _)
Obeservables take away a lot of problems you will have with event based systems
Handling subsrcriptions
Handling errors
Filtering and pre-processing events
Buffering events
Structuring the API
Your API should provide an obesrvable for each event source you have. For procedure calls you provide a function that will map the function call to an obesrvable. This function will call the remote procedure and provide the result through the obeservable.
Implementation details
Add the following dependency to your build.sbt:
libraryDependencies += "com.netflix.rxjava" % "rxjava-scala" % "0.15.0"
You can then use the following pattern to convert a callback to an obeservable (given your remote API has some way to register and unregister a callback):
private val callbackFunc : (rx.lang.scala.Observer[String]) => rx.lang.scala.Subscription = { o =>
val listener = {
case Value(s) => o.onNext(s)
case Error(e) => o.onError(o)
}
remote.subscribe(listener)
// Return an interface to cancel the subscription
new Subscription {
val unsubscribed = new AtomicBoolean(false)
def isUnsubscribed: Boolean = unsubscribed.get()
val asJavaSubscription: rx.Subscription = new rx.Subscription {
def unsubscribe() {
remote.unsubscribe(listener)
unsubscribed.set(true)
}
}
}
If you have some specific questions, just ask and I can refine the answer
Additional ressources
There is a very nice course from Martin Odersky et al. at coursera, covering Observables and other reactive techniques.
Take a look at the spray-client library. This provides HTTP request functionality (I'm assuming the server you want to talk to is a web service?). It gives you a pretty nice DSL for building requests and is all about being asynchronous. It does use the akka Actor model behind the scenes, but you do not have to build your own Actors to use it. Instead the you can just use scala's Future model for handling things asynchronously. A good introduction to the Future model is here.
The basic building block of spray-client is a "pipeline" which maps an HttpRequest to a Future containing an HttpResponse:
// this is from the spray-client docs
val pipeline: HttpRequest => Future[HttpResponse] = sendReceive
val response: Future[HttpResponse] = pipeline(Get("http://spray.io/"))
You can take this basic building block and build it up into a client API in a couple of steps. First, make a class that sets up a pipeline and defines some intermediate helpers demonstrating ResponseTransformation techniques:
import scala.concurrent._
import spray.can.client.HttpClient
import spray.client.HttpConduit
import spray.client.HttpConduit._
import spray.http.{HttpRequest, HttpResponse, FormData}
import spray.httpx.unmarshalling.Unmarshaller
import spray.io.IOExtension
type Pipeline = (HttpRequest) => Future[HttpResponse]
// this is basically spray-client boilerplate
def createPipeline(system: ActorSystem, host: String, port: Int): Pipeline = {
val httpClient = system.actorOf(Props(new HttpClient(IOExtension(system).ioBridge())))
val conduit = system.actorOf(props = Props(new HttpConduit(httpClient, host, port)))
sendReceive(conduit)
}
private var pipeline: Pipeline = _
// unmarshalls to a specific type, e.g. a case class representing a datamodel
private def unmarshallingPipeline[T](implicit ec:ExecutionContext, um:Unmarshaller[T]) = (pipeline ~> unmarshal[T])
// for requests that don't return any content. If you get a successful Future it worked; if there's an error you'll get a failed future from the errorFilter below.
private def unitPipeline(implicit ec:ExecutionContext) = (pipeline ~> { _:HttpResponse => () })
// similar to unitPipeline, but where you care about the specific response code.
private def statusPipeline(implicit ec:ExecutionContext) = (pipeline -> {r:HttpResponse => r.status})
// if you want standard error handling create a filter like this
// RemoteServerError and RemoteClientError are custom exception classes
// not shown here.
val errorFilter = { response:HttpResponse =>
if(response.status.isSuccess) response
else if(response.status.value >= 500) throw RemoteServerError(response)
else throw RemoteClientError(response)
}
pipeline = (createPipeline(system, "yourHost", 8080) ~> errorFilter)
Then you can use wrap these up in methods tied to specific requests/responses that becomes the public API. For example, suppose the service has a "ping" GET endpoint that returns a string ("pong") and a "form" POST endpoint where you post form data and receive a DataModel in return:
def ping()(implicit ec:ExecutionContext, um:Unmarshaller[String]): Future[String] =
unmarshallingPipeline(Get("/ping"))
def form(formData: Map[String, String])(implicit ec:ExecutionContext, um:Unmarshaller[DataModel]): Future[DataModel] =
unmarshallingPipeline(Post("/form"), FormData(formData))
And then someone could use the API like this:
import scala.util.{Failure, Success}
API.ping() foreach(println) // will print out "pong" when response comes back
API.form(Map("a" -> "b") onComplete {
case Success(dataModel) => println("Form accepted. Server returned DataModel: " + dataModel)
case Failure(e) => println("Oh noes, the form didn't go through! " + e)
}
I'm not sure if you will find direct support in spray-client for your third bullet point about subscribing to events. Are these events being generated by the server and somehow sent to your client outside the scope of a specific HTTP request? If so, then spray-client will probably not be able to help directly (though your event handlers could still use it to send requests). Are the events occurring on the client side, e.g. the completion of deferred processing initially triggered by a response from the server? If so, you could actually probably get pretty far just by using the functionality in Future, but depending on your use cases, using Actors might make sense.