I don't know why my code is not working, I've tried with Postman and works fine:
But with RestTemplate I can´t get a response while it´s using the same endpoint... .
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.DELETE, new HttpEntity<NotificationRestDTO[]>(arrNotif), String.class);
I've tried with List instead Array[]
When i made a PUT request it´s works fine but with one object:
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.PUT, new HttpEntity<NotificationRestDTO>(notificationDTO), String.class);
Any help?? Thanks!!
From the comments it became clear that you're expecting it to return a 400 Bad Request response. RestTemplate will see these as "client errors" and it will throw a HttpClientErrorException.
If you want to handle cases like this, you should catch this exception, for example:
try {
ResponseEntity<String> responseMS = template.exchange(notificationRestService, HttpMethod.DELETE, new HttpEntity<NotificationRestDTO[]>(arrNotif), String.class);
} catch (HttpClientErrorException ex) {
String message = ex.getResponseBodyAsString();
}
In this case (since you expect a String), you can use the getResponseBodyAsString() method.
The ResponseEntity will only contain the data in case your request can be executed successfully (2xx status code, like 200, 204, ...). So, if you only expect a message to be returned if the request was not successfully, you can actually do what Mouad mentioned in the comments and you can use the delete() method of the RestTemplate.
Related
I'm looking for a simple example of error handling with WebFlux. I've read lots of stuff online, but can't find something that fits what I want.
I'm running with Spring Boot 2.45
I am calling services like this:
Mono<ResponseObject> mono = webClient.post()
.uri(url.toString())
.header("Authorization", authToken)
.body(Mono.just(contract), contract.getClass())
.retrieve()
.bodyToMono(ResponseObject.class);
All of my services return Json that is deserialized to ResposeObject which looks something like this:
"success" : true,
"httpStatus": 200,
"messages" : [
"Informational message or, if not 200, then error messages"
],
result: {
"data": {}
}
data is simply a map of objects that are the result of the service call.
If there is an error, obviously success is false.
When I eventually do a ResponseObject response = mono.block(), I want to get a ResponseObject each time, even if there was an error. My service returns a ResponseObject even if it returns an http status of 400, but WebFlux seems to intercept this and throws an exception. Obviously, there might also be 400 and 500 errors where the service wasn't even called. But I still want to wrap whatever message I get into a ResponseObject. How can I eliminate all exceptions and always get a ResponseObject returned?
Update
Just want to clarify that the service itself is not a Reactive Webflux service. It is not returning a Mono. Instead, it is calling out to other Restful services, and I want to do that using Webflux. So what I do is I call the external service, and then this service does a block(). In most cases, I'm calling multiple services, and then I do a Mono.zip and call block() to wait for all of them.
This seems to be what I want to do: Spring Webflux : Webclient : Get body on error, but still can't get it working. Not sure what exchange() is
Correct way of handling this is via .onErrorResume that allows you to subscribe to a fallback publisher using a function, when any error occurs. You can look at the generated exception and return a custom fallback response.
You can do something like this:
Mono<ResponseObject> mono = webClient.post()
.uri(url.toString())
.header("Authorization", authToken)
.bodyValue(contract)
.exchangeToMono(response -> {
if (response.statusCode().equals(HttpStatus.OK)) {
return response.bodyToMono(ResponseObject.class);
}
else if (response.statusCode().is4xxClientError()) {
return response.bodyToMono(ResponseObject.class);
}
else {
Mono<WebClientResponseException> wcre = response.createException();
// examine wcre and create custom ResponseObject
ResponseObject customRO = new ResponseObject();
customRO.setSuccess(false);
customRO.setHttpStatus(response.rawStatusCode());
// you can set more default properties in response here
return Mono.just( customRO );
}
});
Moreover, you should not be using .block() anywhere in your Java code. Just make sure to return a Mono<ResponseObject> from your REST controller. If you want to examine response before returning to client you can do so in a .map() hander like this at the end of pipeline (right after .onErrorResume handler)
.map(response -> {
// examine content of response
// in the end just return it
return response;
});
I am using web client in a spring application
I am facing memory leak issues while doing the same
I am using below code to get the response body for non 2XX response from service:
return client.get()
.uri(uriString)
.headers(ServiceCommonUtil.getHttpHeaderConsumer(headersMap))
.exchange()
.flatMap(clientResponse -> {
try {
clientResponse.body((clientHttpResponse, context) ->
clientHttpResponse.getBody());
logResponseStatus(clientResponse.statusCode(), serviceName);
return clientResponse.bodyToMono(String.class);
} catch (Exception e) {
return null;
}
})
and later on subscriber uses subscribe/ error block to process this response.
responseMono.subscribe(response -> {
//process response string
},error->{
//process error response
});
My question is, if i use dispose method on responseMono, it takes way long time for processing while without it i face memory leak issues.
Am i doing anything wrong here?
Yes, actually you are not consumming response in case of Exception is thrown.
If you want to use exchange() your responsibillity is to consume response.
See: docs
Take a look on toBodilessEntity()/ releaseBody() in 'ClientResponse` api.
Seems you've gotten a little complicated. Why a try/catch block in the clientResponse lambda? If your logResponseStatus throws a checked exception then handle it there. I suggest starting simpler.
Ex 1:
Mono<String> stringMono = webClient.get().uri("test").header("head", "value").exchange().flatMap(clientResponse->clientResponse.bodyToMono(String.class));
stringMono.subscribe(System.out::println);
Ex 2:
Mono<String> stringMono = webClient.get().uri("test").header("head", "value").exchange().flatMap(clientResponse->clientResponse.body(BodyExtractors.toMono(String.class)));
stringMono.subscribe(System.out::println);
Ex 3:
Mono<String> stringMono = webClient.get().uri("test").header("head", "value").retrieve().bodyToMono(String.class);
stringMono.subscribe(System.out::println);
For logging it is better to use ExchangeFilterFunctions. See How to intercept a request when using SpringBoot WebClient
.
I can do this for POST
ResponseEntity<ResponseMessage> response = restTemplate.postForEntity(URL, animal, ResponseMessage.class);
return response.getBody();
But why there is no putForEntity for PUT? There is just resTemplate.put(...
How do I do it for 'PUT' request.
You can use:
restTemplate.exchange(url, HttpMethod.PUT, requestEntity, ...)
Here is the link to the documentation of this method.
You can use PUT instead, reason why putForEntity is not available because as per standard PUT will not return a response body but 201 or 200 in most of the cases.
I can easily get the expected JSON response if I send the following get request from my browser:
http://www.bookandwalk.hu/api/AdminTransactionList?password=XXX&begindate=2016-04-30&enddate=2016-10-12&corpusid=HUBW
I tried to use SPRING BOOT 1.4 to create a small demo app to see how rest calls work in Spring.
So I created a POJO representing my domain object and I requested the list of domain objects by the following method invocation:
String startDate=new SimpleDateFormat("yyyy-MM-dd").format(start.getTime());
String endDate=new SimpleDateFormat("yyyy-MM-dd").format(end.getTime());
UriComponents uri=UriComponentsBuilder.newInstance().scheme("http").host("www.bookandwalk.hu").path("/api/AdminTransactionList").queryParam("password","xxx").queryParam("begindate",startDate).queryParam("enddate",endDate).queryParam("corpusid","HUBW").build().encode();
LOG.log(Level.INFO,"{0} were called as a rest call",uri.toString());
ResponseEntity<List<BandWTransaction>> transResponse =
restTemplate.exchange(uri.toString(),
HttpMethod.GET, null, new ParameterizedTypeReference<List<BandWTransaction>>() {
});
List<BandWTransaction> transactions = transResponse.getBody();
I got the following exception:
org.springframework.web.client.HttpClientErrorException: 404 Not Found
As I logged the uri.toString(), I copied it to my browser to double check the is there any typos in my uri but it was working without any failure.
Does Anybody have idea why the same string works from the browser but not from the code?
It seems that you should specify a user agent header in the request for this webapp. Use a HttpEntity object to set this header.
final HttpHeaders headers = new HttpHeaders();
headers.set("User-Agent", "eltabo");
final HttpEntity<String> entity = new HttpEntity<String>(headers);
ResponseEntity<List<BandWTransaction>> transResponse =
restTemplate.exchange(uri.toString(),
HttpMethod.GET, entity,
new ParameterizedTypeReference<List<BandWTransaction>>() {});
Hope it helps.
I have the following code in my web application:
#ExceptionHandler(InstanceNotFoundException.class)
#ResponseStatus(HttpStatus.NO_CONTENT)
public ModelAndView instanceNotFoundException(InstanceNotFoundException e) {
return returnErrorPage(message, e);
}
Is it possible to also append a status message to the response? I need to add some additional semantics for my errors, like in the case of the snippet I posted I would like to append which class was the element of which the instance was not found.
Is this even possible?
EDIT: I tried this:
#ResponseStatus(value=HttpStatus.NO_CONTENT, reason="My message")
But then when I try to get this message in the client, it's not set.
URL u = new URL ( url);
HttpURLConnection huc = (HttpURLConnection) u.openConnection();
huc.setRequestMethod("GET");
HttpURLConnection.setFollowRedirects(true);
huc.connect();
final int code = huc.getResponseCode();
String message = huc.getResponseMessage();
Turns out I needed to activate custom messages on Tomcat using this parameter:
-Dorg.apache.coyote.USE_CUSTOM_STATUS_MSG_IN_HEADER=true
The message can be in the body rather than in header. Similar to a successful method, set the response (text, json, xml..) to be returned, but set the http status to an error value. I have found that to be more useful than the custom message in header. The following example shows the response with a custom header and a message in body. A ModelAndView that take to another page will also be conceptually similar.
#ExceptionHandler(InstanceNotFoundException.class)
public ResponseEntity<String> handle() {
HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.set("ACustomHttpHeader", "The custom value");
return new ResponseEntity<String>("the error message", responseHeaders, HttpStatus.INTERNAL_SERVER_ERROR);
}