Package discord4j.rest.http.client

Class ClientException

java.lang.Object
java.lang.Throwable
java.lang.Exception
java.lang.RuntimeException
discord4j.rest.http.client.ClientException
All Implemented Interfaces:
Serializable
public class ClientException extends RuntimeException
Exception that contains information about a failed request containing HTTP response data.

The original request can be retrieved through getRequest(). HTTP response status can be retrieved by getStatus(), headers using getHeaders(), while the body can be retrieved through getErrorResponse() provided Discord has supplied a body along with the error.

It is possible to modify the behavior of a reactive sequence that has failed with this error, using operators like Mono.onErrorResume(Predicate, Function), Mono.onErrorContinue(Predicate, BiConsumer) among others. In cases where a Predicate is accepted, you can use one of the provided static methods like isStatusCode(int) to further filter by HTTP status code.

The following example would retry a request if it has failed with an HTTP 500 error: 

 client.getEventDispatcher().on(MessageCreateEvent.class)
     .map(MessageCreateEvent::getMessage)
     .filter(msg -> msg.getContent().map("!ping"::equals).orElse(false))
     .flatMap(Message::getChannel)
     .flatMap(channel -> channel.createMessage("Pong!")
         .transform(ClientException.retryOnceOnStatus(500)))
     .subscribe();
While the following one would transform a not found user into an empty sequence: 
 client.getUserById(Snowflake.of(userLongId))
     .onErrorResume(ClientException.isStatusCode(404), error -> Mono.empty())
     .subscribe(user -> System.out.println("Found: " + user.getUsername()));
For global or Route based error handling, refer to the ResponseFunction class.
See Also:

  • Constructor Details

  • Method Details

    • getRequest

      public ClientRequest getRequest()
      Return the ClientRequest encapsulating a Discord API request.
      Returns:
      the request that caused this exception

    • getResponse

      public HttpClientResponse getResponse()
      Return the HttpClientResponse encapsulating a low-level Discord API response.
      Returns:
      the low-level response that caused this exception

    • getStatus

      public HttpResponseStatus getStatus()
      Return the HttpResponseStatus with information related to the HTTP error. The actual status code can be obtained through HttpResponseStatus.code().
      Returns:
      the HTTP error associated to this exception

    • getHeaders

      public HttpHeaders getHeaders()
      Return the HttpHeaders from the error response. To get request headers refer to getRequest() and then ClientRequest.getHeaders().
      Returns:
      the HTTP response headers

    • getErrorResponse

      public Optional<ErrorResponse> getErrorResponse()
      Return the HTTP response body in the form of a Discord ErrorResponse, if present. ErrorResponse is a common object that contains an internal status code and messages, and could be used to further clarify the source of the API error.
      Returns:
      the Discord error response, if present

    • isStatusCode

      public static Predicate<Throwable> isStatusCode(int code)
      Predicate helper to further classify a ClientException depending on the underlying HTTP status code.
      Parameters:
      code - the status code for which this Predicate should return true
      Returns:
      a Predicate that returns true if the given Throwable is a ClientException containing the given HTTP status code

    • isStatusCode

      public static Predicate<Throwable> isStatusCode(Integer... codes)
      Predicate helper to further classify a ClientException depending on the underlying HTTP status code.
      Parameters:
      codes - the status codes for which this Predicate should return true
      Returns:
      a Predicate that returns true if the given Throwable is a ClientException containing the given HTTP status code

    • emptyOnStatus

      public static <T> Function<Mono<T>,Publisher<T>> emptyOnStatus(int code)
      Transformation function that can be used within an operator such as Mono.transform(Function) or Mono.transformDeferred(Function) to turn an error sequence matching the given HTTP status code, into an empty sequence, effectively suppressing the original error.
      Type Parameters:
      T - the type of the response
      Parameters:
      code - the status code that should be transformed into empty sequences
      Returns:
      a transformation function that converts error sequences into empty sequences

    • retryOnceOnStatus

      public static <T> Function<Mono<T>,Publisher<T>> retryOnceOnStatus(int code)
      Transformation function that can be used within an operator such as Mono.transform(Function) or Mono.transformDeferred(Function) to apply a retrying strategy in case of an error matching the given HTTP status code. The provided retrying strategy will wait 1 second, and then retry once.
      Type Parameters:
      T - the type of the response
      Parameters:
      code - the status code that should be retried
      Returns:
      a transformation function that retries error sequences