I'm using Spring WebFlux for my project that is intended to work as pub/sub service: http clients connect to it and wait for events (like PUSH or SSE).
I need to manually write headers and body to the response without using ServerResponse.
I need to do it manually because I'm implementing an SSE server and I must send custom headers into the response before any event actually arrives.
I'm trying to do it this way:
#Bean
RouterFunction<ServerResponse> getStuff() {
return route(GET("/stuff"),
request -> {
final ServerWebExchange exchange = request.exchange();
final byte[] bytes = "data".getBytes(StandardCharsets.UTF_8);
final DataBuffer buffer =exchange.getResponse().bufferFactory().wrap(bytes);
return exchange.getResponse().writeWith(Flux.just(buffer));
}
);
But it does not work because writeWith() returns Mono<Void> and getStuff() must return RouterFunction. Can anybody help me find a way around this?
Related
I'm currently using ExchangeFilterFunction to log all Headers that come inside the ClientRequest instance and I'm accessing to them doing request.headers().
After my filter is executed, the HttpClient underneath is adding certain headers such as the Accept-Encoding one, thus not getting logged, as they never get added to the ClientRequest instance.
My filter looks like this:
public class WebClientLoggingFilter implements ExchangeFilterFunction {
#Override
public Mono<ClientResponse> filter(final ClientRequest clientRequest, final ExchangeFunction next) {
return Mono.just(clientRequest)
.doOnNext(request -> log(request.headers().toString()))
.flatMap(next::exchange)
.doOnNext(clientResponse -> logData(clientRequestData, message, clientResponse));
}
}
This filter logs everything inside ClientRequest headers, but then HttpClient does its magic, which never arrives at the ClientRequest, even after the response is back. Example of code from Netty.
Is there any other way I can do the logging so I can get access to what it's truly being sent through the network?
Instead of using a filter, I'd recommend utilising the standard loggers by adding these lines to your resources/application.properties:
spring.http.log-request-details=true
logging.level.org.springframework.web.reactive.function.client.ExchangeFunctions=TRACE
However, by default, this will still show headers as {headers masked} (as they may contain sensitive data). To enable header logging for a client, you must explicitly enable it on each WebClient as follows:
return WebClient
.builder()
.exchangeStrategies(ExchangeStrategies.builder().codecs(c ->
c.defaultCodecs().enableLoggingRequestDetails(true)).build()
)
.build()
//carry on using the webclient as normal
You'll then get output similar to the following:
HTTP POST https://a.com/ea, headers=[Content-Type:"application/json", Accept:"application/json", Authorization:"Bearer token blah"]
The configuration property to use has changed to:
spring.codec.log-request-details=true
Basically, we have a big monolithic application built on Spring Boot v1.2 and we would like to handle some business rules processing from a MicroService (let's call it BR engine) built on Spring Boot v2.1.6.
How can I intercept the requestBody and send it first to BR engine and then once done, it will either proceed to the actual handler (Monolithic Controller) or not based from BR engine results - for simplicity let's say BR engine returns either true or false. If true, proceed to actual handler if false, return an exception.
I wanted to use HandlerInterceptorAdapter however, not sure how I can intercept the requestBody and pass it to a microservice - then from the results it will either proceed or not to the actual handler.
As an example, let's say I have a POST mapping to the Monolithic controller:
#PostMapping("/save")
public ResponseEntity<Client> save(#RequestBody ClientDTO dto) {
log.debug("Saving...");
Client newClient = Client.builder().build();
BeanUtils.copyProperties(dto, newClient);
return new ResponseEntity<>(clientService.save(newClient), HttpStatus.OK);
}
Now I wanted to intercept the ClientDTO requestBody and send it first to the BR engine and do some stuff from there. I have thought of using an interceptor and add it to my config which implements WebMvcConfigurer. However, I am not sure how can perform a restTemplate here and get a response from BR engine of pass or fail - if fail the actual handler will be skipped and just throw an exception
#Component
public class RuleEngineInterceptor extends HandlerInterceptorAdapter {
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
// intercept requestBody then send it to BR engine
// but how? and how can I get the response from BR engine
// to decide whether it will proceed to actual handler
// or not - probably return an exception.
return true;
}
I am supposed to interact with a legacy system where I have to setup a TCP client using spring-integration in java/kotlin to send a message to a TCP system and receive its response, parse this response and send it to other client via REST. I went through many documentations and blogs which tells how to do via xml. Not able to find corresponding annotations for everything. Any code snippet will be very helpful.
#Service
class MyService{
#Autowired
MyGateway gateway;
public String callTCPClient(String msg){
return gateway.exchange(msg);
}
}
interface MyGateway{
String exchange (String msg)
}
As is shown in that answer, you can do whatever you want after the response is received...
#Bean
public IntegrationFlow client() {
return IntegrationFlows.from(MyGateway.class)
.handle(Tcp.outboundGateway(
Tcp.netClient("localhost", 1234)
.serializer(codec()) // default is CRLF
.deserializer(codec()))) // default is CRLF
.transform(Transformers.objectToString()) // byte[] -> String
.get();
}
In this case, we simply transform the byte array to a String, but you can perform whatever operations you want on it, e.g. JSON to Object. You can add as many steps as you want - add .handle(...) elements to call arbitrary methods. Read the Spring Integration Reference Manual.
I want to make a route that will be triggered from client request.
For example I have a route http://localhost:8080/get where I have some json object.
I want to create a route when I send a request to http://localhost:8080/get to send the data to ActiveMQ. Like event listener. I want to send to activeMq only when there is request to that URL.
I have searched that I cant use http or http4 in from() and that makes me a problem. I have tried from timer to url and then to activemq, but that is not what I really need.
This is what I have tried.
#GetMapping(value = "/shit")
public String getIt(#RequestParam(value = "url") String url, #RequestParam(value = "activemq") String activeMq) throws Exception {
CamelContext camelContext = new DefaultCamelContext();
RouteBuilder builder = new RouteBuilder() {
public void configure() {
from(url).convertBodyTo(String.class)
.process(exchange -> {
String body = exchange.getIn()
.getBody()
.toString();
System.out.println("The body is: " + body);
})
.pollEnrich()
.simple("activemq://" + activeMq);
}
};
builder.addRoutesToCamelContext(camelContext);
camelContext.start();
return "";
}
And I want the route to be active untill I stop it.
Yeah, camel-http4 is to produce only, it is not usable as a consumer because it is based an Apache HTTP client.
But you don't need special things like a timer or enricher. You can just use another Camel http-component that can act as a server. For example camel-jetty.
After a long discussion I finally realized that you would like to "branch off" requests within your other, already existing applications, i.e. you would like to send an incoming request, additionally to process them, to ActiveMQ.
Unfortunately you cannot do this from outside your applications because you do not know about incoming requests in other applications without modifying those other applications.
However, if you can modify your other applications so that they send their payloads to your new Camel application, the route would be quite simple:
from("jetty:http://localhost:[port]/yourApp")
.to("activemq:queue:myQueueName")
This route acts as a webserver for /yourApp
and sends the message body to a message queue of the configured ActiveMQ broker.
I am working in a Spring #Component class and I am trying to get the HTTP status code of a particular URL for further processing. I have a function as follows:
fun getStatus() : String
{
val webClient = WebClient.create("https://stackoverflow.com")
val result = webClient.get()
.exchange().map { res -> res.rawStatusCode() }
println(result)
return "statusGotten"
}
However, rather than getting the Int value of the status code (e.g. 200, or 401), I am simply getting: "MonoMap".
I am new to both Spring and Web Programming in general, so I'm a little confused how to proceed from here. I'm aware that "result" is being returned as a "Mono", but I'm less clear about what a "Mono" is, or how I might transform it into something with more scrutable properties, as even looking at "result" in the debugger doesn't shed any light as to whether the HTTP request was actually sent or was successful:
Am I calling the webclient incorrectly? Or merely failing to parse the resultant data in a meaningful way? Any suggestions on how or where I might learn more about the underlying topics would be much appreciated as well.
If you need a blocking way to do this is easy just
#Test
public void myTest(){
WebClient client = WebClient.builder().baseUrl("https://stackoverflow.com/").build();
ClientResponse resp = client
.get()
.uri("questions/")
.exchange()
.block();
System.out.println("Status code response is: "+resp.statusCode());
}
But for this you can use directly the RestTemplate instead the webclient... the recomended way to do this is non blocking what means you should return a Mono with the status and consume outside your method like for example:
public Mono<HttpStatus> myMethod(){
WebClient client = WebClient.builder().baseUrl("https://stackoverflow.com/").build();
return client
.get()
.uri("questions/")
.exchange()
.map( clientResp -> clientResp.statusCode());
}
The way of consume this Mono depends of your code...