JDA Bot Exception

I have a problem while creating a Java bot for Discord. I decided to make a command for it to kick players from the server. But I ran into difficulties.

Here's a code :

package com.company;
import net.dv8tion.jda.api.EmbedBuilder;
import net.dv8tion.jda.api.Permission;
import net.dv8tion.jda.api.entities.Member;
import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
import net.dv8tion.jda.api.hooks.ListenerAdapter;
import java.util.List;
import java.util.Objects;
public class KickComm extends ListenerAdapter {
public void onGuildMessageReceived(GuildMessageReceivedEvent event) {
String[] args = event.getMessage().getContentRaw().split("\\s+");
List<Member> mentionedMembers = event.getMessage().getMentionedMembers();
Member target = mentionedMembers.get(0);
if(args[0].equalsIgnoreCase(Main.prefix + "kick"))
{
if (args.length < 2) {                                                                  //TODO NOT WORK
EmbedBuilder NoUser = new EmbedBuilder();
NoUser.setColor(0xff3923);
NoUser.setTitle("\uD83D\uDD34You need to add a <@username> and <reason>");
NoUser.setFooter("Usage: " + Main.prefix + "kick <@username> <reason>.",
Objects.requireNonNull(event.getMember()).getUser().getAvatarUrl());
event.getChannel().sendMessage(NoUser.build()).queue();
NoUser.clear();
}
else if (args.length < 3) {                                                                //WORK
EmbedBuilder NoReason = new EmbedBuilder();
NoReason.setColor(0xff3923);
NoReason.setTitle("\uD83D\uDD34You need to add a <reason>.");
NoReason.setFooter("Usage: " + Main.prefix + "kick <@username> <reason>.",
Objects.requireNonNull(event.getMember()).getUser().getAvatarUrl());
event.getChannel().sendMessage(NoReason.build()).queue();
NoReason.clear();
}
else if(!Objects.requireNonNull(event.getMember()).hasPermission(Permission.KICK_MEMBERS)  //WORK
&&
!event.getMember().canInteract(target)) {
EmbedBuilder NoPermission = new EmbedBuilder();
NoPermission.setColor(0xff3923);
NoPermission.setTitle("\uD83D\uDD34You don't have permission to use this command.");
NoPermission.setFooter("Usage: " + Main.prefix + "kick <@username> <reason>.",
Objects.requireNonNull(event.getMember()).getUser().getAvatarUrl());
event.getChannel().sendMessage(NoPermission.build()).queue();
NoPermission.clear();
}
else if(mentionedMembers.isEmpty()) {                                                       //TODO NOT WORK 
EmbedBuilder NoMember = new EmbedBuilder();
NoMember.setColor(0xff3923);
NoMember.setTitle("\uD83D\uDD34I don't see member with this nickname.");
NoMember.setFooter("Usage: " + Main.prefix + "kick <@username> <reason>.",
Objects.requireNonNull(event.getMember()).getUser().getAvatarUrl());
event.getChannel().sendMessage(NoMember.build()).queue();
NoMember.clear();
}
}
}
}

Promlem in two lines :

if (args.length < 2) {

And

else if(mentionedMembers.isEmpty()) {

Most of all, I can't understand why line 1 does not work. When I write the !kick command in the discord, the console displays an error :

java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0

I don't know why args length is 0, it's very strange.I tried to "if-else-if" to "if", but it doesn't work.I really wanna to continue creating that command, but i don't know what to do.

P.S.:it's not all of code, because i can't progress further due to this error.Sorry for my Google translater english and many thanks

The exception is caused by this line:

Member target = mentionedMembers.get(0);

Your problem here is that not every message may mention a member. Keep in mind you also receive your own messages. If the bot only sends an embed, the content will be empty.

If the content is only whitespace your split("\\s+") will return an empty array. This will cause an ArrayIndexOutOfBoundsException on this line:

if(args[0].equalsIgnoreCase(Main.prefix + "kick"))

I would recommend checking for the length of mentionedMembers and checking for the length of args before trying to access their respective elements.