I am building a (mostly) pass through API with RestTemplate which queries various different services. On errors and missing parameters the target APIs deliver error messages which go missing in the responses and I want to pass those through with the same HttpCode. Example:
curl -XPOST sourceapi:/...
{"type":"/errors/failed","title":"Entity Exists","details":"Entity with name \"test\" already exists","status":409}
If I do the same with a RestTemplate it throws and Exception and the message is null and it looks like this:
curl -XPOST testapi:/...
409 null
How can I pass error code as well as that object there down to the "client". (even logging it would be a start...)
I got a #ControllerAdvice class which already caches it but the message is actually just 409 null
#ExceptionHandler(value = {HttpClientErrorException.class})
public ResponseEntity<Object> clientErrorException(HttpClientErrorException ex) {
return ResponseEntity.status(ex.getStatusCode()).body(ex.getMessage());
}
Is there a way to add an ErrorParser or something while building the Template with RestTemplateBuilder?
Isn't getResponseBodyAsString() method (inherited from RestClientResponseException) what you seek?
#ExceptionHandler(value = {HttpClientErrorException.class})
public ResponseEntity<Object> clientErrorException(HttpClientErrorException ex) {
return ResponseEntity.status(ex.getStatusCode()).body(ex.getResponseBodyAsString());
}
Or perhaps getResponseBodyAsByteArray() would be a better fit.
Related
On my quarkus rest project i have a restclient that uses mutiny:
#Path("/")
#RegisterRestClient(configKey = "my-api")
#RegisterClientHeaders
#RegisterProvider(MyExceptionMapper.class)
public interface MyClient {
#POST
#Path("path")
Uni<MyBean> get(String body);
}
I wanna handle propery non 2XX httpError so i have made my ExceptionMaper
public class MyExceptionMapper implements ResponseExceptionMapper<MyException> {
#Override
public MyException toThrowable(Response response) {
//TODO
return new MyException();
}
}
a bad call on the client shows that MyExceptionMapper handle the response but the exception raises and does not became a failure on my Uni Client response object
Uni<MyBean> bean = myClient.get("") // i do not have a failure in case of 4XX http
.onFailure().invoke(fail -> System.out.println("how can i get here?"));
Am i using mutiny on a rest client in the wrong way?
Thanks
UPDATE
ok i forgot to add the dependency quarkus-rest-client-mutiny, adding this i notice 2 things,
i still pass through Myexceptionmapper
i also produce a Uni.failure, but the exception into the failure is not the custom exception i created into MyExceptionmapper but a RestEasyWebApplicationException
Failure : org.jboss.resteasy.client.exception.ResteasyWebApplicationException: Unknown error, status code 400
at org.jboss.resteasy.client.exception.WebApplicationExceptionWrapper.wrap(WebApplicationExceptionWrapper.java:107)
at org.jboss.resteasy.microprofile.client.DefaultResponseExceptionMapper.toThrowable(DefaultResponseExceptionMapper.java:21)
Does the ExceptionMapper becomes useless in this context?
I think this is a bug in quarkus-rest-client-mutiny. I created an Github issue based on your findings.
It will work as you expect if you switch to quarkus-rest-client-reactive
I am implementing all the methods of ResponseEntityExceptionHandler because i don't want Spring to send any standard error responses towards the client. There are two seemingly similar methods that confuse me a bit. Namely handleExceptionInternal and handleException. These are the definitions of both methods according to the official documentation.
handleException(Exception ex, WebRequest request)
Provides handling for standard Spring MVC exceptions.
handleExceptionInternal(Exception ex, Object body, HttpHeaders headers, HttpStatus status, WebRequest request)
A single place to customize the response body of all exception types.
I find these explanations a bit vague. What can be considered 'standard spring mvc exceptions' for example? And should handleExceptionInternal be considered like a 'default' handler method that is used when none of the other methods can catch the spring exception? Please correct me if i'm wrong.
Thank you
handleException method is a common exception handler for standard spring mvc exceptions. Its main task is it maps these exception to respective status code as per http response code convention, which most likely you are not going to change.
e.g.
HttpRequestMethodNotSupportedException -> 405
HttpMediaTypeNotSupportedException -> 415
NoHandlerFoundException -> 404
All these exceptions are handled in their specific handler methods handle{ExceptionName} so that for some reason, if you want to change the status code (or add response body for detailed info), you can do so by overriding specific handler. All these handlers further delegate to handleExceptionInternal.
One thing you have noticed each handle{ExceptionName} methods pass body as null to handleExceptionInternal. These methods just return the status code with no body which doesn't give you more details about the error.
A common practice is to return a custom error response body with details so that your api consumers know the exact error cause. This is the place you can inject your custom body by creating an Error object. A simple error message would look like.
public class ApiError {
private final int status;
private final int message;
public ApiError(int status, int message) {
this.status = status;
this.message = message;
}
// getters
}
And you can override handleExceptionInternal method as:
#Override
protected ResponseEntity<Object> handleExceptionInternal(Exception ex, Object body, HttpHeaders headers, HttpStatus status, WebRequest request) {
ApiError error = new ApiError(status.value(), ex.getMessage());
return super.handleExceptionInternal(ex, error, headers, status, request);
}
Summary
If handleException wouldn't there, then you need to manually map each exceptions to respective error code. If handleExceptionInternal were missing then to inject error body you would need to override each handle{Exception} methods.
Update
RFC for http status code definition.
I have two REST API's GET POST
When any Exception is thrown inside the method, Exception handler is working fine.
But if i use malformed REST api uri then it only shows 400 Bad Request without going to Exception Handler.
Eg.
If I hit http://localhost:8080/mypojoInteger/abc, it fails to parse string into Integer and hence I am expecting it to go to ExceptionHandler.
It does not go to Exception Handler, Instead I only see 400 Bad Request.
It works fine and goes to Exception Handler when any Exception is thrown inside the GET/POST method.
For eg: It works fine and goes to Exception Handler if I use 123 in path variable
http://localhost:8085/mypojoInteger/123
And change getData method to
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Integer sentNumber) {
throw new NumberFormatException("Exception");
}
NOTE: Same issue is with POST request also.
GET:
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Integer sentNumber) {
//some code
}
POST:
public void postData(#RequestBody MyPojo myPojo) {
//some code
}
Controller Advice class:
#ControllerAdvice
public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(NumberFormatException.class)
protected ResponseEntity<Object> handleEntityNotFound(
NumberFormatException ex) {
// some logic
}
}
How can I handle Exception when it fails to bind String to Integer in REST API uri itself??
EDIT: My Requirement is I should handle the overflow value of integer i.e, If a pass more than maximum value of Integer it must handle it rather than throwing NumberFormatException Stack Trace.
Eg: When i pass over flow value
POJO:
public class MyPojo extends Exception {
private String name;
private Integer myInt;
//getters/setter
}
{
"name":"name",
"myInt":12378977977987879
}
Without #ControllerAdvice it just shows the NumberFormatException StackTrace.
With #ControllerAdvice it just shows 400 bad request with no Response Entity.
I do not want this default stacktrace/400 bad request in case of this scenario
but I want to show my custom message.
The reason that i see is that, because since your request itself is malformed-> the method body never gets executed - hence the exception never occurs because it is only meant to handle the error within the method . It is probably a better design choice for you to form a proper request body rather than allowing it to execute any method so you know the problem before hand.
The issue is because Integer object is not sent as a valid request parameter, example of request: 5 if you send String an exception will be thrown directly. If you want to check if it is a String or Integer you might change your code by following this way:
#GetMapping("/mypojoInteger/{sentNumber}")
public void getData(#PathVariable("sentNumber") Object sentNumber) {
if (!(data instanceof Integer)) {
throw new NumberFormatException("Exception");
}
}
This should work on your example.
Solution:
I found out that I need to handle Bad Request.
So, I have override
#Override
protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
//Handle Bad Request
}
I have this Jersey2-based application, with a custom ContainerRequestFilter.
When the filter(ContainerRequestContext) method is called I want to do a check and, if needed, I want to be able to stop the request before entering the main logic of the application.
At the moment I'm using the ContainerRequestContext#abortWith method to block the call and return an "error" response to the client.
My application returns JSONP to the client, and if I block with abortWith the response is always a JSON.
Looking at the jersey sources I found
org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor that is responsible of the JSONP serialization.
In the abortWith flow I see it fails to find the JSONP annotation, but I don't know where it search for it.
My method has it, in fact in the "normal" scenario (without the abortWith) I see correctly the JSONP format.
I found the solution.
The ContainerRequestFilter#filter method was something like
public void filter(final ContainerRequestContext crc) throws IOException {
if (/* logic */) {
CustomObject ret = new CustomObject();
ret.error = "error message";
crc.abortWith(Response.ok(ret)).build());
}
}
JsonWithPaddingInterceptor expected a response with a JSONP annotation so I retrieve them from the ResourceInfo#resourceMethod, with something like
public void filter(final ContainerRequestContext crc) throws IOException {
if (/* logic */) {
Annotation[] as = this.resourceInfo.getResourceMethod().getAnnotations();
CustomObject ret = new CustomObject();
ret.error = "error message";
crc.abortWith(Response.ok().entity(ret, as).build());
}
}
this way the annotation is correctly found
When a client request for a resource producing application/json content with Accept Header of application/xml. The request fails with HttpMediaTypeNotAcceptableException exception and is wrapped into error message body in the response entity object by using exception handler annotation as mentioned in below code. However, we receive HttpMediaTypeNotAcceptableException again when return values are written to the response with HttpMessageConverter. It is because it checks the producible content type for the response with the acceptable request type, but this is exactly something we are trying to communicate to the client using error message. How do I workaround this issue ? Btw, all the other exceptions are parsing fine to error message. Please advise.
#ControllerAdvice
public class RestExceptionHandler extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleExceptionInternal(Exception ex, Object body,
HttpHeaders headers, HttpStatus status, WebRequest request) {
// Setting the response content type to json
headers.setContentType(MediaType.APPLICATION_JSON);
return ResponseEntity.status(status).headers(headers).body(body);
}
}
A few options come to my mind. One is that your controller method produces all content types and then you throw an exception in your method if the content type is not the one you are expecting, then the exception handler can take this exception and transform it. This is the only one that works with exception handlers, as exception handlers only deal with exceptions produced in the controller method.
The other options are:
Use an interceptor (but I'm not sure if this will work, as Spring might try to resolve first the controller method rather than invoking the interceptors).
Extend RequestMappingHandlerMapping to call the exception handler if it doesn't find a suitable method. You'll probably need to override the method handleNoMatch. In there you'll need to get a reference to the list of HandlerExceptionResolver
The first one is the simplest to understand, and the latest one might be the most 'extensible', but it also requires some understanding of the internals of Spring.
Resolved by setting different content negotiation strategy FixedContentNegotiationStrategy for ExceptionHandlerExceptionResolver and HeaderContentNegotiationStrategy for RequestResponseBodyMethodProcessor.
I have been using a serialized enum-based response (enum annotated with jackson #JsonFormat(shape = Shape.OBJECT) to standardize the error messages in my exception handler class and faced the same issue when it caught with a HttpMediaTypeNotAcceptableException.
The workaround is to set the media type you expect to return directly to the builder method available in the ResponseEntity.
The below code works fine for me.
#ExceptionHandler(HttpMediaTypeNotAcceptableException.class)
public final ResponseEntity<ResponseMessagesEnum> handleHttpMediaTypeNotAcceptableException(
HttpMediaTypeNotAcceptableException e, HttpServletRequest request) {
logger.error("No acceptable representation found for [{}] | supported {}", request.getHeader("Accept"), e.getSupportedMediaTypes());
return ResponseEntity.status(HttpStatus.BAD_REQUEST).contentType(MediaType.APPLICATION_JSON)
.body(ResponseMessagesEnum.EX_001);
}