java.lang.Object

net.dv8tion.jda.api.exceptions.ErrorHandler

All Implemented Interfaces:: Consumer<Throwable>

public class ErrorHandler extends Object implements Consumer<Throwable>

Utility class to simplify error handling with RestActions and ErrorResponses.

Example


 // Send message to user and delete it 30 seconds later, handles blocked messages in context channel.
 public void sendMessage(TextChannel context, User user, String content) {
     user.openPrivateChannel()
         .flatMap(channel -> channel.sendMessage(content))
         .delay(Duration.ofSeconds(30))
         .flatMap(Message::delete) // delete after 30 seconds
         .queue(null, new ErrorHandler()
             .ignore(ErrorResponse.UNKNOWN_MESSAGE) // if delete fails that's fine
             .handle(
                 ErrorResponse.CANNOT_SEND_TO_USER,  // Fallback handling for blocked messages
                 (e) -> context.sendMessage("Failed to send message, you block private messages!").queue()));
 }

Since:

4.2.0

See Also:

Constructor Summary

Constructors

Constructor

Description

ErrorHandler()

Create an ErrorHandler with RestAction.getDefaultFailure() as base consumer.

ErrorHandler(Consumer<? super Throwable> base)

Create an ErrorHandler with the specified consumer as base consumer.
Method Summary

Modifier and Type

Method

Description

void

accept(Throwable t)

<T> ErrorHandler

handle(Class<T> clazz, Consumer<? super T> handler)

Handle specific throwable types.

<T> ErrorHandler

handle(Class<T> clazz, Predicate<? super T> condition, Consumer<? super T> handler)

Handle specific throwable types.

ErrorHandler

handle(Collection<Class<?>> clazz, Predicate<? super Throwable> condition, Consumer<? super Throwable> handler)

Handle specific throwable types.

ErrorHandler

handle(Collection<ErrorResponse> errorResponses, Consumer<? super ErrorResponseException> handler)

Handle specific ErrorResponses.

ErrorHandler

handle(Predicate<? super Throwable> condition, Consumer<? super Throwable> handler)

Handle specific conditions.

ErrorHandler

handle(ErrorResponse response, Consumer<? super ErrorResponseException> handler)

Handle specific ErrorResponses.

ErrorHandler

ignore(Class<?> clazz, Class<?>... classes)

Ignore exceptions of the specified types.

ErrorHandler

ignore(Collection<ErrorResponse> errorResponses)

Ignore the specified set of error responses.

ErrorHandler

ignore(Predicate<? super Throwable> condition)

Ignore exceptions on specific conditions.

ErrorHandler

ignore(ErrorResponse ignored, ErrorResponse... errorResponses)

Ignore the specified set of error responses.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Consumer
andThen

Constructor Details
- ErrorHandler
  
  public ErrorHandler()
  
  Create an ErrorHandler with RestAction.getDefaultFailure() as base consumer.
  If none of the provided ignore/handle cases apply, the base consumer is applied instead.
- ErrorHandler
  
  public ErrorHandler(@Nonnull Consumer<? super Throwable> base)
  
  Create an ErrorHandler with the specified consumer as base consumer.
  If none of the provided ignore/handle cases apply, the base consumer is applied instead.
  
  Parameters:
  
  base - The base Consumer
Method Details
- ignore
  
  @Nonnull public ErrorHandler ignore(@Nonnull ErrorResponse ignored, @Nonnull ErrorResponse... errorResponses)
  Ignore the specified set of error responses.
  Example
  
  // Creates a message with the provided content and deletes it 30 seconds later public static void selfDestruct(MessageChannel channel, String content) { channel.sendMessage(content) .delay(Duration.ofSeconds(30)) .flatMap(Message::delete) .queue(null, new ErrorHandler().ignore(UNKNOWN_MESSAGE)); }
  Parameters:
  
  ignored - Ignored error response
  
  errorResponses - Additional error responses to ignore
  
  Returns:
  
  This ErrorHandler with the applied ignore cases
  
  Throws:
  
  IllegalArgumentException - If provided with null
- ignore
  
  @Nonnull public ErrorHandler ignore(@Nonnull Collection<ErrorResponse> errorResponses)
  Ignore the specified set of error responses.
  Example
  
  // Creates a message with the provided content and deletes it 30 seconds later public static void selfDestruct(User user, String content) { user.openPrivateChannel() .flatMap(channel -> channel.sendMessage(content)) .delay(Duration.ofSeconds(30)) .flatMap(Message::delete) .queue(null, new ErrorHandler().ignore(EnumSet.of(UNKNOWN_MESSAGE, CANNOT_SEND_TO_USER))); }
  Parameters:
  
  errorResponses - The error responses to ignore
  
  Returns:
  
  This ErrorHandler with the applied ignore cases
  
  Throws:
  
  IllegalArgumentException - If provided with null
- ignore
  
  @Nonnull public ErrorHandler ignore(@Nonnull Class<?> clazz, @Nonnull Class<?>... classes)
  Ignore exceptions of the specified types.
  Example
  
  // Ignore SocketTimeoutException public static void ban(Guild guild, String userId) { guild.ban(userId).queue(null, new ErrorHandler().ignore(SocketTimeoutException.class); }
  Parameters:
  
  clazz - The class to ignore
  
  classes - Additional classes to ignore
  
  Returns:
  
  This ErrorHandler with the applied ignore case
  
  Throws:
  
  IllegalArgumentException - If provided with null
  
  See Also:
  
  SocketTimeoutException
- ignore
  
  @Nonnull public ErrorHandler ignore(@Nonnull Predicate<? super Throwable> condition)
  Ignore exceptions on specific conditions.
  Example
  
  // Ignore all exceptions except for ErrorResponseException public static void ban(Guild guild, String userId) { guild.ban(userId).queue(null, new ErrorHandler().ignore((ex) -> !(ex instanceof ErrorResponseException)); }
  Parameters:
  
  condition - The condition to check
  
  Returns:
  
  This ErrorHandler with the applied ignore case
  
  Throws:
  
  IllegalArgumentException - If provided with null
  
  See Also:
  
  ErrorResponseException
- handle
  
  @Nonnull public ErrorHandler handle(@Nonnull ErrorResponse response, @Nonnull Consumer<? super ErrorResponseException> handler)
  Handle specific ErrorResponses.
  This will apply the specified handler to use instead of the base consumer if one of the provided ErrorResponses happens.
  Example
  
  public static void sendMessage(TextChannel context, User user, String content) { user.openPrivateChannel() .flatMap(channel -> channel.sendMessage(content)) .queue(null, new ErrorHandler() .handle(ErrorResponse.CANNOT_SEND_TO_USER, (ex) -> context.sendMessage("Cannot send direct message, please enable direct messages from server members!").queue())); }
  Parameters:
  
  response - The first ErrorResponse to match
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
  
  Throws:
  
  IllegalArgumentException - If provided with null
- handle
  
  @Nonnull public ErrorHandler handle(@Nonnull Collection<ErrorResponse> errorResponses, @Nonnull Consumer<? super ErrorResponseException> handler)
  Handle specific ErrorResponses.
  This will apply the specified handler to use instead of the base consumer if one of the provided ErrorResponses happens.
  Example
  
  public static void sendMessage(TextChannel context, User user, String content) { user.openPrivateChannel() .flatMap(channel -> channel.sendMessage(content)) .queue(null, new ErrorHandler() .handle(EnumSet.of(ErrorResponse.CANNOT_SEND_TO_USER), (ex) -> context.sendMessage("Cannot send direct message, please enable direct messages from server members!").queue())); }
  Parameters:
  
  errorResponses - The ErrorResponses to match
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
  
  Throws:
  
  IllegalArgumentException - If provided with null
- handle
  
  @Nonnull public <T> ErrorHandler handle(@Nonnull Class<T> clazz, @Nonnull Consumer<? super T> handler)
  Handle specific throwable types.
  This will apply the specified handler if the throwable is of the specified type. The check is done using Class.isInstance(Object).
  Example
  
  public static void logErrorResponse(RestAction<?> action) { action.queue(null, new ErrorHandler() .handle(ErrorResponseException.class, (ex) -> System.out.println(ex.getErrorResponse()))); }
  Type Parameters:
  
  T - The type
  
  Parameters:
  
  clazz - The throwable type
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
- handle
  
  @Nonnull public <T> ErrorHandler handle(@Nonnull Class<T> clazz, @Nonnull Predicate<? super T> condition, @Nonnull Consumer<? super T> handler)
  Handle specific throwable types.
  This will apply the specified handler if the throwable is of the specified type. The check is done using Class.isInstance(Object).
  Example
  
  public static void logErrorResponse(RestAction<?> action) { action.queue(null, new ErrorHandler() .handle(ErrorResponseException.class, ErrorResponseException::isServerError, (ex) -> System.out.println(ex.getErrorCode() + ": " + ex.getMeaning()))); }
  Type Parameters:
  
  T - The type
  
  Parameters:
  
  clazz - The throwable type
  
  condition - Additional condition that must apply to use this handler
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
- handle
  
  @Nonnull public ErrorHandler handle(@Nonnull Collection<Class<?>> clazz, @Nullable Predicate<? super Throwable> condition, @Nonnull Consumer<? super Throwable> handler)
  Handle specific throwable types.
  This will apply the specified handler if the throwable is of the specified type. The check is done using Class.isInstance(Object).
  Example
  
  public static void logErrorResponse(RestAction<?> action) { action.queue(null, new ErrorHandler() .handle(Arrays.asList(Throwable.class), (ex) -> ex instanceof Error, (ex) -> ex.printStackTrace())); }
  Parameters:
  
  clazz - The throwable types
  
  condition - Additional condition that must apply to use this handler, or null to apply no additional condition
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
- handle
  
  @Nonnull public ErrorHandler handle(@Nonnull Predicate<? super Throwable> condition, @Nonnull Consumer<? super Throwable> handler)
  Handle specific conditions.
  Example
  
  public static void logErrorResponse(RestAction<?> action) { action.queue(null, new ErrorHandler() .handle( (ex) -> !(ex instanceof ErrorResponseException), Throwable::printStackTrace)); }
  Parameters:
  
  condition - Condition that must apply to use this handler
  
  handler - The alternative handler
  
  Returns:
  
  This ErrorHandler with the applied handler
- accept
  
  public void accept(Throwable t)
  
  Specified by:
  
  accept in interface Consumer<Throwable>

Class ErrorHandler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.function.Consumer

Constructor Details

ErrorHandler

ErrorHandler

Method Details

ignore

ignore

ignore

ignore

handle

handle

handle

handle

handle

handle

accept