I have an API method that need send response using HttpServletResponse.getOutputStream(). Is possible to return error response with some http status code when error occurs when outputstream is used like that ? In below code i'm getting Cannot call sendError() after the response has been committed exception and response not completed response but with status 200. I think that because stream is opened and something was written already... Any workaround for this situation?
#GetMapping(path = "/test")
public void test(HttpServletResponse resp) {
try (
OutputStream out = resp.getOutputStream();
) {
// writing to out...
// writing to out...
// ...
// some error occurs
// ...
} catch(IOException e) {
// Cannot call sendError() after the response has been committed
resp.sendError(500, "something wrong");
}
}
Related
I have some usage issue about okhttp in 3.14.9 release
if i want add LoggingInterceptor for each request, how can i get response body, which can only consume once?
And follow is my attemp
public class LoggingRequestInterceptor implements Interceptor {
#Override
public Response intercept(Chain chain) throws IOException {
Request request = chain.request();
Response response = chain.proceed(request);
log.debug(
"{}, {}, {}, {}, {}, {}, {}",
request.url(),
request.method(),
JSONUtil.toJsonStr(request.body()),
request.headers(),
dup.body() == null ? null : dup.body().string());
return response;
}
}
It will throw exception of stream closed, how to fix it?
Use peekBody for this
val client = OkHttpClient.Builder()
.addInterceptor {
val response = it.proceed(it.request())
println(response.peekBody(1000000).string())
response
}
.build()
I do research for this issue. We can use buffer, which is in RequestBody-source-getBuffer.
Working code is below:
public String getResponseBody(Response response) {
try {
ResponseBody responseBody = response.body();
if (!ObjectUtil.isNull(responseBody)) {
BufferedSource source = responseBody.source();
source.request(Long.MAX_VALUE);
Buffer buffer = source.getBuffer();
return buffer.clone().readString(UTF8);
}
} catch (IOException e) {
log.error("get response body failed: ", e);
}
return null;
}
From ernest-kiwele:
Using a try with a resources block with the response causes this "closed" problem when the response body is read outside of the try block:
try (Response response = client.newCall(request.build()).execute()) {
return response;
} //response.close() called implicitly by the JVM
The fix is to restructure the code to only use the response within the try block.
I am using spring-boot. I want to send a CSV as the attachment of response for which I am using opencsv to write bean to response. Even though response.getWriter() is called only once, I am getting this exception.
While searching for solution, I came to know that we cannot use response.getWriter() and response.getOutputStream() together. But this is not the case here.
I am only calling getWriter and exactly once.
I also checked if it was due to opencsv library by writing a plain string to it e.g. "name, test". But still the same error. So it's not due to opencsv either.
private Pair<Boolean, String> writeCSVToResponse(List<QuestionDownloadResponse> qdrList, HttpServletResponse response) {
String fileName = new SimpleDateFormat("'CSV'yyyyMMddHHmmss'.csv'").format(new Date());
response.reset();
response.setContentType("application/csv");
response.setHeader(HttpHeaders.CONTENT_DISPOSITION,
"attachment; filename=\"" + fileName + "\"");
response.setCharacterEncoding("UTF-8");
//Find answer, for now we will return any if exists
try {
Writer writer = response.getWriter();
// Create Mapping Strategy to arrange the
// column name in order
final CustomCSVMappingStrategy<QuestionDownloadResponse> mappingStrategy = new CustomCSVMappingStrategy<>();
mappingStrategy.setType(QuestionDownloadResponse.class);
StatefulBeanToCsv<QuestionDownloadResponse> sbc = new StatefulBeanToCsvBuilder<QuestionDownloadResponse>(writer)
.withSeparator(CSVWriter.DEFAULT_SEPARATOR)
.withMappingStrategy(mappingStrategy)
.build();
sbc.write(qdrList);
} catch (IOException e) {
CMSQuestionServiceImpl.logger.error("Error in CSV IO operations", e);
return Pair.of(false, "Failed to Open file");
} catch (CsvDataTypeMismatchException | CsvRequiredFieldEmptyException e) {
CMSQuestionServiceImpl.logger.error("Error in CSV Write operation", e);
return Pair.of(false,"Failed to write in csv");
}
}
Why is this exception coming, even when response.getWriter is called exactly once. How to solve this issue.
I found the issue. The problem was that I was sending a String (a message) in response in the controller, but in service, I am sending an attachment. So getWriter() was being called first time in service by me, and the second time by spring to write the response message of type String. Solution: I set the return type of method in the controller to void ex::
#GetMapping(value = "/downloadCSV")
public void downloadCSV(#RequestBody(required = false) List<Integer> items, HttpServletResponse response){
The only problem is if something goes wrong in service, you cannot send an error message and there are other alternatives to overcome it.
I had the same error: in spring-boot
This error occures when we use a RestExceptionHandler which tries to modify the response by using response.getOutputStream(), remember, the response.getWriter() is already called (even once in our code).
So when we call response.getWriter() , and we have some exception, the RestExceptionHandler executes the response.getOutputStream() which causes java.lang.IllegalStateException: getWriter() has already been called for this response.
What I suggest to do is to add try-catch to the response.getWriter() and when you catch any exception we have to reset the response by using response.reset() like that:
try {
writer.write(beans);
} catch (Exception e) {
response.reset();
throw e;
}
After throwing the exception the RestExceptionHandler will do it's job.
I'm using The spring rest-template for calling the rest URL , I get a response from the server but the http-status code is invalid and the Spring throws , java.lang.IllegalArgumentException: No matching constant . Due to this exception the application is failing , this looks like a bug in the Spring code . Since the http status code received is not in the list spring framework is looking forit failed . Is there a Spring way to handle it ?
Spring seems to use the standard status code in their enum. You can find the status codes here: org.springframework.http.HttpStatus.
Probably the API you're querying is not returning a standard HTTP Status code. Your best bet is to create a custom error handler, like this:
var r = new RestTemplate();
r.setErrorHandler(new ResponseErrorHandler() {
#Override
public boolean hasError(ClientHttpResponse response) throws IOException {
return response.getRawStatusCode() != 550;
}
#Override
public void handleError(ClientHttpResponse response) {
// Do nothing?
}
});
var response = r.exchange("https://httpbin.org/status/550", HttpMethod.GET, null, String.class);
System.out.println(response.getStatusCodeValue());
What we're saying is basically if the status code returned is 550 (not a standard code), we don't want to do anything about it.
Another option you have is, of course, to catch the exception and do something about it.
try {
// Call the API here
} catch (IllegalArgumentException e) {
// Do something about it here...
}
HttpClientErrorException always produces the following result for me:
HttpClientErrorException: 400 null
... and the null part is what worries me. Shouldn't this be the place where the message of the server-side exception is supposed to be?
I checked the source code of the HTTP client to see where the client-side exception is thrown. It looks like this:
throw new HttpClientErrorException(statusCode, response.getStatusText(), response.getHeaders(), getResponseBody(response), getCharset(response));
Debugging this call revealed that response.getStatusText() is null in my case.
My question is: How do you design your ResponseEntity on the server-side such that the HTTP client finds the server-side exception message in response.getStatusText() instead of null?
Here is my Exception
#ExceptionHandler({ MyCustomException.class })
public ResponseEntity<String> handleException(final HttpServletRequest
req, final MyCustomException e) {
HttpHeaders headers = new HttpHeaders();
headers.set("Content-type", "text/plain");
String body = e.toString();
return new ResponseEntity<>(body, headers, HttpStatus.BAD_REQUEST);
}
I want to send POST request with Retrofit + RxJava, but it is failing and I don't know the reason. In one activity it's working, in another - don't want to work:
private void sendMerchantInfo() {
try {
String advertiserOriginalDeepLink = "https://mywebsite.com/main-1?param1=value1¶m2=value2";
String urlGetParams = LinkParser.getUrlGETParams(advertiserOriginalDeepLink);
Map<Object, Object> merchantInfo = LinkParser.parseUrlGetParams(urlGetParams);
String merchantInfoJson = new Gson().toJson(merchantInfo); //{"param1":"value1","param2":"value2"}
String url = "https://api.endpoint.com/v1/system/merchant/process";
userService = this.serviceGenerator.createService(UserService.class, true);
final Observable observable = userService.sendUserInfo(
url, new RetrofitMapBody(merchantInfo))
.doOnNext(new Consumer<ResponseBody>() {
#Override
public void accept(ResponseBody responseBody) throws Exception {
//handle 200 OK.
}
})
.onErrorResumeNext((ObservableSource<? extends ResponseBody>) v ->
Crashlytics.log("Send user info attempt failed."))
.subscribeOn(Schedulers.from(threadExecutor))
.observeOn(postExecutionThread.getScheduler());
addDisposable(observable.subscribe());
}
} catch (Exception exception) {
Crashlytics.log("Send user info attempt failed. " + exception.getMessage());
}
}
I suspect that problem in this part, I am trying to send request in OnCreate() method:
.subscribeOn(Schedulers.from(threadExecutor))
.observeOn(postExecutionThread.getScheduler());
Tried to use this, but no effect:
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());
What I am doing wrong? It always call onErrorResumeNext() It's probably something with threads because one time I got exception: networkonmainthreadexception. Please help.
Try using RxJava2 Adapter, it will save you a lot!
Step 1: Retrofit client setup
private Retrofit getRetrofitClient() {
return new Retrofit.Builder()
.baseUrl(BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJava2CallAdapterFactory.create()) //option 1
.addCallAdapterFactory(RxJava2CallAdapterFactory.createWithScheduler(Schedulers.newThread())) //option 2
.build();
}
Step 2: APIService interface (Example)
#GET("endpoint")
Single<ResponseModel> fetch();
Step 3: Usage
Single<ResponseModel> fetch() {
return getRetrofitClient()
.create(APIService.class)
.fetch();
}
Any non-2xx HTTP response will be wrapped in HttpException from which you can extract the status code, the status message and the full HTTP response.
Any connection errors will be wrapped in IOException
And that is all you need to do to wrap your network call in any RxJava stream.