JDA Hello World

public class Main {
    public static void main(String[] args) throws LoginException, InterruptedException {

        // Bot token
        final String token = "DISCORD_TOKEN";

        JDA jda = JDABuilder.createDefault(token)
                .setStatus(OnlineStatus.ONLINE)

                // Event Listeners
                .addEventListeners(
                        new HelloWorld()
                )

                .enableCache(CacheFlag.VOICE_STATE)
                .enableIntents(GatewayIntent.MESSAGE_CONTENT, GatewayIntent.GUILD_MEMBERS)
                .setMemberCachePolicy(MemberCachePolicy.ALL)

                .build()
                .awaitReady();
    }
}

// Triggers for EVERY message sent
public class HelloWorld extends ListenerAdapter {

    @Override
    public void onMessageReceived(@NotNull MessageReceivedEvent event) {
        event.getMessage().reply("Hello, world!").queue();
    }
}