Error Handling

Exceptions

JDA-Commands defines a set of custom runtime exceptions that can occur:

• ConfigurationException will be thrown if anything goes wrong while configuring JDA-Commands.
• InvalidDeclarationException will be thrown if any errors are made in the declaration of interactions.
• InternalException will be thrown if anything goes wrong internally. These errors should be reported to the devs.

If a ConfigurationException or InvalidDeclarationException occurs during startup, JDA-Commands will shut down itself as well as JDA. To disable this behaviour, set JDACBuilder#shutdownJDA(boolean) to false.

Error Messages

As mentioned before, JDA-Commands has a set of error messages it uses all over the place. These messages include:

• Command Execution Failed Message (used for Exceptions)
• Constraint Failed Message (see Validators)
• Cooldown Message (see Command Cooldown)
• Insufficient Permissions Message (see Permissions System)
• Timed Out Component Message (see Runtime Concept)
• Type Adapting Failed Message (see Type Adapters)

You can customize these error messages by providing an implementation of ErrorMessageFactory. You have to register it at the JDA-Commands Builder:

JDACommands.builder(jda, Main.class)
    .errorMessageFactory(new OwnErrorMessageFactory());
    .start();

Or use the @Implementation annotation (requires the Guice Extension):

@Implementation
public class OwnErrorMessageFactory implements ErrorMessageFactory {...}

To make things easier, these error messages can also be loaded from a JSON source using the Embed API. Therefore, you have to pass an EmbedDataSource to the EmbedConfig.

JDACommands.builder(jda, Main.class)
    .embeds(config -> config.errorSource(EmbedDataSource.file(Path.of("errorEmbeds.json")))
    .start();

The template for the error messages can be found here. The { $placeholders } can be placed anywhere in the embeds and will get injected by JDA-Commands.