How quarkus.arc.dev-mode.monitoring-enabled works? - quarkus

The application has classes that uses quarkus-reactive-client to request external information.
Also this classes has a provider to map http errors to a custom exception.
In prod mode all works fine but in dev mode, for default, instead of returned my custom exception, the method returns a ArcUndeclaredThrowableException.
If the property quarkus.arc.dev-mode.monitoring-enabled is set to false, all works fine in dev mode.
I try to understand what does this property do and why it changes the behaviour in dev mode.
Thanks.
Rest client
#Path("/")
#RegisterRestClient
#ClientHeaderParam(name = "Connection", value = "close")
#RegisterProviders({
#RegisterProvider(value = OidcClientRequestReactiveFilter.class),
#RegisterProvider(value = SomeResponseExceptionMapper.class)})
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public interface SomeClient {
#GET
#Path("/some/url/{identifier}")
SomeDTO search(#PathParam("identifier") String identifier)
throws CustomException;
Method use rest client method
private SomeDTO search(String identifier) throws CustomException {
try {
return someClient.search(identifier);
} catch (CustomException e) {
....
}
return null;
}
Error console
(executor-thread-0) io.quarkus.arc.ArcUndeclaredThrowableException: Error invoking subclass method

Related

Hystrix fallback method returns null

I implemented feign client and hystrix to my spring boot microservice application.
I first tried to test to communicate users service to albums service with feign client,
so I threw an exception at albums service to check if users service Error Decoder can catch the exception and then make the fallback method triggered.
It worked, but the cause is always null only at the first time, and after that I can see the error message that I wanted to see.
Can anyone tell me if something is wrong or not.
This is my code.
Users Service Feign Client
#FeignClient(name = "albums-ws", fallbackFactory = AlbumsFallbackFactory.class)
public interface AlbumServiceClient {
#GetMapping(path = "users/{userId}/albums")
List<AlbumDetailResponse> getAlbums(#PathVariable("userId") String userId);
}
Fallback Factory
#Component
public class AlbumsFallbackFactory implements FallbackFactory<AlbumServiceClient> {
#Override
public AlbumServiceClient create(Throwable cause) {
return new AlbumServiceClientFallback(cause);
}
}
public class AlbumServiceClientFallback implements AlbumServiceClient {
private final Throwable cause;
private final Logger logger = LoggerFactory.getLogger(this.getClass());
public AlbumServiceClientFallback(Throwable cause) {
this.cause = cause;
}
#Override
public List<AlbumDetailResponse> getAlbums(String userId) {
logger.error("An exception took place: " + cause.getMessage());
return new ArrayList<>();
}
}
Feign Error Decoder
#Component
public class FeignErrorDecoder implements ErrorDecoder {
#Override
public Exception decode(String methodKey, Response response) {
switch(response.status()) {
case 400:
break;
case 404:
if(methodKey.contains("getAlbums")) {
return new ResponseStatusException(HttpStatus.valueOf(response.status()), response.reason());
}
break;
default:
return new Exception(response.reason());
}
return null;
}
}
First fallback triggered
2020-08-02 12:42:27.836 ERROR 24772 --- [ HystrixTimer-1] c.a.p.a.u.P.f.AlbumServiceClientFallback : An exception took place: null
After
2020-08-02 12:43:07.672 DEBUG 24772 --- [rix-albums-ws-2] c.a.p.a.u.P.feign.AlbumServiceClient : [AlbumServiceClient#getAlbums] User not found with id: f5b313e2-411f-4fc3-95e7-9aa5c43c286c
Hystrix has class org.springframework.cloud.netflix.feign.HystrixTargeter. There is a comment in targetWithFallbackFactory method:
We take a sample fallback from the fallback factory to check if it
returns a fallback that is compatible with the annotated feign
interface.
and code after:
Object exampleFallback = fallbackFactory.create(new RuntimeException());
It is why you don't have cause in exception.

Spring Boot Exception(Error) Handling for RESTful Services

I have the following RESTful Services method :
#PostMapping("/ajouterNewField")
public String ajouterField(#Valid #ModelAttribute("field") Fields field, Model model) throws IOException {
fieldDao.save(field);
// SOME CODE
return displayListeChamps( model);
}
The method is working fine and my question is how to handle any error (database not connected ...) or every issue that can happen durring the execution of this RESTful Services method.
You can use #ControllerAdvice
Refer to the code below
#ControllerAdvice
public String NyExceptionHandlerAdvice {
private final Logger logger = ...;
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
#ExceptionHandler({MyRunTimeException.class})
public void handleMyRunTimeException(Exception e) {
logger.error("Exception : ", e);
}
return MY_ERROR_STRING;
}
Best Practice is:
You can have your code throw RunTimeExceptions and handle all of them together or separately in handler methods similar to handleMyRunTimeException above.
You can decide what status code your request should return upon exception.
Basically you'll have to a sort of exception handler for any kind of exception your method might throw:
public class FooController{
// ...
#ExceptionHandler({ CustomException1.class, CustomException2.class })
public void handleException() {
//
}
}
Here's a nice article about that: https://www.baeldung.com/exception-handling-for-rest-with-spring

Spring WS (DefaultWsdl11Definition) HTTP status code with void

We have a (working) SOAP web service based on Spring WS with DefaultWsdl11Definition.
This is basically what it looks like:
#Endpoint("name")
public class OurEndpoint {
#PayloadRoot(namespace = "somenamespace", localPart = "localpart")
public void onMessage(#RequestPayload SomePojo pojo) {
// do stuff
}
}
It is wired in Spring and it is correctly processing all of our SOAP requests. The only problem is that the method returns a 202 Accepted. This is not what the caller wants, he'd rather have us return 204 No Content (or if that is not possible an empty 200 OK).
Our other endpoints have a valid response object, and do return 200 OK. It seems void causes 202 when 204 might be more appropriate?
Is it possible to change the response code in Spring WS? We can't seem to find the correct way to do this.
Things we tried and didn't work:
Changing the return type to:
HttpStatus.NO_CONTENT
org.w3c.dom.Element <- not accepted
Adding #ResponseStatus <- this is for MVC, not WS
Any ideas?
Instead of what I wrote in the comments it is possibly the easiest to create a delegation kind of solution.
public class DelegatingMessageDispatcher extends MessageDispatcher {
private final WebServiceMessageReceiver delegate;
public DelegatingMessageDispatcher(WebServiceMessageReceiver delegate) {
this.delegate = delegate;
}
public void receive(MessageContext messageContext) throws Exception {
this.delegate.receive(messageContext);
if (!messageContext.hasResponse()) {
TransportContext tc = TransportContextHolder.getTransportContext();
if (tc != null && tc.getConnection() instanceof HttpServletConnection) {
((HttpServletConnection) tc.getConnection()).getHttpServletResponse().setStatus(200);
}
}
}
}
Then you need to configure a bean named messageDispatcher which would wrap the default SoapMessageDispatcher.
#Bean
public MessageDispatcher messageDispatcher() {
return new DelegatingMessageDispatcher(soapMessageDispatcher());
}
#Bean
public MessageDispatcher soapMessageDispatcher() {
return new SoapMessageDispatcher();
}
Something like that should do the trick. Now when response is created (In the case of a void return type), the status as you want is send back to the client.
When finding a proper solutions we've encountered some ugly problems:
Creating custom adapters/interceptors is problematic because the handleResponse method isn't called by Spring when you don't have a response (void)
Manually setting the status code doesn't work because HttpServletConnection keeps a boolean statusCodeSet which doesn't get updated
But luckily we managed to get it working with the following changes:
/**
* If a web service has no response, this handler returns: 204 No Content
*/
public class NoContentInterceptor extends EndpointInterceptorAdapter {
#Override
public void afterCompletion(MessageContext messageContext, Object o, Exception e) throws Exception {
if (!messageContext.hasResponse()) {
TransportContext tc = TransportContextHolder.getTransportContext();
if (tc != null && tc.getConnection() instanceof HttpServletConnection) {
HttpServletConnection connection = ((HttpServletConnection) tc.getConnection());
// First we force the 'statusCodeSet' boolean to true:
connection.setFaultCode(null);
// Next we can set our custom status code:
connection.getHttpServletResponse().setStatus(204);
}
}
}
}
Next we need to register this interceptor, this can be easily done using Spring's XML:
<sws:interceptors>
<bean class="com.something.NoContentInterceptor"/>
</sws:interceptors>
A big thanks to #m-deinum for pointing us in the right direction!
To override the afterCompletion method really helped me out in the exact same situation. And for those who use code based Spring configuration, here´s how one can add the interceptor for a specific endpoint.
Annotate the custom interceptor with #Component, next register the custom interceptor to a WsConfigurerAdapter like this:
#EnableWs
#Configuration
public class EndpointConfig extends WsConfigurerAdapter {
/**
* Add our own interceptor for the specified WS endpoint.
* #param interceptors
*/
#Override
public void addInterceptors(List<EndpointInterceptor> interceptors) {
interceptors.add(new PayloadRootSmartSoapEndpointInterceptor(
new NoContentInterceptor(),
"NAMESPACE",
"LOCAL_PART"
));
}
}
NAMESPACE and LOCAL_PART should correspond to the endpoint.
If someone ever wanted to set custom HTTP status when returning non-void response, here is solution:
Spring Boot WS-Server - Custom Http Status

Get failure exception in #HystrixCommand fallback method

Is there a way to get the reason a HystrixCommand failed when using the #HystrixCommand annotation within a Spring Boot application? It looks like if you implement your own HystrixCommand, you have access to the getFailedExecutionException but how can you get access to this when using the annotation? I would like to be able to do different things in the fallback method based on the type of exception that occurred. Is this possible?
I saw a note about HystrixRequestContext.initializeContext() but the HystrixRequestContext doesn't give you access to anything, is there a different way to use that context to get access to the exceptions?
Simply add a Throwable parameter to the fallback method and it will receive the exception which the original command produced.
From https://github.com/Netflix/Hystrix/tree/master/hystrix-contrib/hystrix-javanica
#HystrixCommand(fallbackMethod = "fallback1")
User getUserById(String id) {
throw new RuntimeException("getUserById command failed");
}
#HystrixCommand(fallbackMethod = "fallback2")
User fallback1(String id, Throwable e) {
assert "getUserById command failed".equals(e.getMessage());
throw new RuntimeException("fallback1 failed");
}
I haven't found a way to get the exception with Annotations either, but creating my own Command worked for me like so:
public static class DemoCommand extends HystrixCommand<String> {
protected DemoCommand() {
super(HystrixCommandGroupKey.Factory.asKey("Demo"));
}
#Override
protected String run() throws Exception {
throw new RuntimeException("failed!");
}
#Override
protected String getFallback() {
System.out.println("Events (so far) in Fallback: " + getExecutionEvents());
return getFailedExecutionException().getMessage();
}
}
Hopefully this helps someone else as well.
As said in the documentation Hystrix-documentation getFallback() method will be thrown when:
Whenever a command execution fails: when an exception is thrown by construct() or run()
When the command is short-circuited because the circuit is open
When the command’s thread pool and queue or semaphore are at capacity
When the command has exceeded its timeout length.
So you can easily get what raised your fallback method called by assigning the the execution exception to a Throwable object.
Assuming your HystrixCommand returns a String
public class ExampleTask extends HystrixCommand<String> {
//Your class body
}
do as follows:
#Override
protected ErrorCodes getFallback() {
Throwable t = getExecutionException();
if (circuitBreaker.isOpen()) {
// Log or something
} else if (t instanceof RejectedExecutionException) {
// Log and get the threadpool name, could be useful
} else {
// Maybe something else happened
}
return "A default String"; // Avoid using any HTTP request or ypu will need to wrap it also in HystrixCommand
}
More info here
I couldn't find a way to obtain the exception with the annotations, but i found HystrixPlugins , with that you can register a HystrixCommandExecutionHook and you can get the exact exception in that like this :
HystrixPlugins.getInstance().registerCommandExecutionHook(new HystrixCommandExecutionHook() {
#Override
public <T> void onFallbackStart(final HystrixInvokable<T> commandInstance) {
}
});
The command instance is a GenericCommand.
Most of the time just using getFailedExecutionException().getMessage() gave me null values.
Exception errorFromThrowable = getExceptionFromThrowable(getExecutionException());
String errMessage = (errorFromThrowable != null) ? errorFromThrowable.getMessage()
this gives me better results all the time.

Map UnsupportedMediaTypeException using ExceptionMapper

Is there a place where it is clearly documented that I cannot map UnsupportedMediaTypeException (because it's a rest easy exception and not custom application exception) using the javax.ws.rs.ext.ExceptionMapper?
I want to prove that to my client. Or another thing I would like to do is map this exception to a Response that can be fetched at the client to show the error. Right now when this exception is thrown it provides no information to the client as the application ends abruptly.
Any help would be appreciated.
Thanks
You can map this exception. Why not? Do you get an error?
This code should do the job
#Provider
public class EJBExceptionMapper implements ExceptionMapper<org.jboss.resteasy.spi.UnsupportedMediaTypeException>{
Response toResponse(org.jboss.resteasy.spi.UnsupportedMediaTypeException exception) {
return Response.status(415).build();
}
}
Don't forget to declare that provider in Spring configuration file.
If you want to provide more information to the client create class
#XmlRootElement
public class Error{
private String message;
//getter and setter for message field
}
and then you can
#Provider
public class EJBExceptionMapper implements ExceptionMapper<org.jboss.resteasy.spi.UnsupportedMediaTypeException>{
Response toResponse(org.jboss.resteasy.spi.UnsupportedMediaTypeException exception) {
Error error = new Error();
error.setMessage("Whatever message you want to send to user");
return Response.entity(error).status(415).build();
}
}
If you don't want to use Error entity simply pass a string to Response.entity() call.
If you want to catch whatever is thrown in you application create generic exception mapper:
#Provider
public class ThrowableMapper implements ExceptionMapper<Throwable> {
public Response toResponse(Throwable t) {
ErrorDTO errorDTO = new ErrorDTO(code);
return Response.status(500).build();
}
}

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