I have some controller method like
#PostMapping("/*")
fun proxy(#RequestBody body: String): Mono<ByteArray> {
return roundRobinBean.getNext()
.post()
.uri("/api")
.body(BodyInserters.fromObject(body))
.retrieve()
.bodyToMono<ByteArray>()
.doOnSuccess{
threadPool.submit(PutToCacheJob(body, it, cacheBean))
}
.doOnError{
logger.error(it.message, it)
}
}
roundRobinBean return WebClient for some host. If i get connection timeout exception or get 500 response i need call another host or return data from cache. Have mono some handler for changing inner data?
You can use onErrorResume operator which lets you define a fallback in case of errors.
Related
I have got a situation that is needed to return HTTP 2XX when WebClient returns any kind of 4XX.
My existing code below,
public Mono<ResponseEntity<>String> postMethodA(String valueA) {
return webClient
.put()
.uri'/')
.bodyValue(valueA)
.retrieve()
.toEntity(String.class);
}
I added onStatus method like this.
public Mono<ResponseEntity<>String> postMethodA(String valueA) {
return webClient
.put()
.uri'/')
.bodyValue(valueA)
.retrieve()
.onStatus(HttpStatus::is4XXClientError response -> Mono.empty())
.toEntity(String.class);
}
If I added
onStatus(HttpStatus::is4XXClientError response -> Mono.empty())
still, it is not gonna work because it is not able to return 2XX.
Is there a way to change the Http status when returning the response? and can you please show some example?
To ignore an error response completely, and propagate neither response
nor error, use a filter, or add onErrorResume downstream, for example:
webClient.get()
.uri("https://someUrl.com/account/123")
.retrieve()
.bodyToMono(Account.class)
.onErrorResume(WebClientResponseException.class,
ex -> ex.getRawStatusCode() == 404 ? Mono.empty() : Mono.error(ex));
Reference: JavaDoc
I am using Spring WebClient to call REST API. I want to throw an error based on the response. For example, if there is an error (400) with body
{"error": "error message1 "}
then I want to throw an error with "error message1". Same way if there is an error(400) with the body
{"error_code": "100020"}
then I want to throw an error with error_cde 100020. I want to do it in a non-blocking way.
public Mono<Response> webclient1(...) {
webClient.post().uri(createUserUri).header(CONTENT_TYPE, APPLICATION_JSON)
.body(Mono.just(request), Request.class).retrieve()
.onStatus(HttpStatus::isError, clientResponse -> {
//Error Handling
}).bodyToMono(Response.class);
}
A body from ClientResponse should be extracted in a reactive way (javadoc) and lambda in onStatus method should return another Mono (javadoc). To sum up, take a look at below example
onStatus(HttpStatus::isError, response -> response
.bodyToMono(Map.class)
.flatMap(body -> {
var message = body.toString(); // here you should probably use some JSON mapper
return Mono.error(new Exception(message));
})
);
I have the below code where I am able to log the headers and URL. But the body() method is returning an object of type BodyInserter. In the debug mode(STS), we can see the request body object. Is there any way to log the request?
[private ExchangeFilterFunction logRequest() {
return ExchangeFilterFunction.ofRequestProcessor(clientRequest -> { loggingService.info(clientRequest.url());
loggingService.info(clientRequest.headers());
BodyInserter<?, ? super ClientHttpRequest> bodyInserters= clientRequest.body();
return Mono.just(clientRequest);
});
}
I'm using Spring Boot to create an API that needs to be consumed in Angular 4. Spring and Angular are on different ports.
The problem is that Spring's ResponseEntity raises an error in Angular.
#RequestMapping(value = "/{id}", method = RequestMethod.GET)
public ResponseEntity getFlow(#PathVariable int id) {
Flow flow = flowService.findById(id);
return new ResponseEntity(flow, HttpStatus.FOUND);
}
Now, I can perfectly use Postman to test the API and it works.
But when I make a request from Angular, it returns an error:
Strangely, it returns an error alongside the requested object.
Now, the cause of the problem is that the Spring Boot application returns a ResponseEntity and not a normal object (like String), and Angular doesn't know how to interpret it. If the controller returns just a Flow object, it works.
How can it be solved using ResponseEntity? Or, how else can I send the object alongside the HTTP status code?
Also, in #RequestMapping put produces = "application/json", and in get request in angular, add http options :
const httpOptions = {
headers: new HttpHeaders({
'Accept': 'application/json',
'Content-Type': 'application/json'
})
};
So your get request looks like this:
this.http.get(url, httpOptions)
As per the document mentioned here
https://docs.angularjs.org/api/ng/service/$http
A response status code between 200 and 299 is considered a success status and will result in the success callback being called. Any response status code outside of that range is considered an error status and will result in the error callback being called. Also, status codes less than -1 are normalized to zero. -1 usually means the request was aborted, e.g. using a config.timeout. Note that if the response is a redirect, XMLHttpRequest will transparently follow it, meaning that the outcome (success or error) will be determined by the final response status code.
As you are sending an instance of ResponseEntity(HttpStatus.Found) whose Http status code is 302 which doesnt fall under the success range thats why error callback is called.
Try returning the content like this
return new ResponseEntity(flow, HttpStatus.OK);
Currently my client authenticates request only on case of 401 response:
this.client.authenticator(new okhttp3.Authenticator() {
public Request authenticate(Route route, Response response) throws IOException {
String credentials = authenticator.getCredentials();
if (credentials.equals(response.request().header("Authorization"))) {
throw new TraversonException(401, "Unauthorized", response.request().url().toString());
} else {
defaultHeader("Authorization", credentials);
Request.Builder newRequest = response.request().newBuilder()
.headers(Headers.of(defaultHeaders));
return newRequest.build();
}
});
But I'd like to change this behavior and be able to call it either manually or auto per first call? Is it possible somehow?
If the authentication is predictably required and not related to a proxy, then the solution is to implement an Interceptor instead of Authenticator.
OkHttpClient.Builder clientBuilder = ...;
clientBuilder.networkInterceptors().add(0, myInterceptor);
client = clientBuilder.build();
Example Interceptor https://github.com/yschimke/oksocial/blob/48e0ca53b85e608443eab614829cb0361c79aa47/src/main/java/com/baulsupp/oksocial/uber/UberAuthInterceptor.java
n.b. There is discussion around possible support for this usecase in https://github.com/square/okhttp/pull/2458. One issue with current Authenticator API is that it assumes a Response from the failed (401) request.