Solved String To Int

So I Am Testing Out Ways To Make The Plugin I Am Making Have Unlimited Levels. So I Convert args[0] to int so i can use my method but it gives me an error when args[0] isnt an int. How do i check if args[0] isnt an int?
Console: https://gyazo.com/f3941e43ad6aa2980a04435fdbb5760b

Code:

package me.albkad.test;

import java.util.List;

import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.java.JavaPlugin;


public class Main extends JavaPlugin {
    SettingsManager settings = SettingsManager.getInstance();
  
    public void onEnable() {
      
    }
  
    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {
      
        if (!(sender instanceof Player)) return true;
        Player p = (Player) sender;
      
        if (cmd.getName().equalsIgnoreCase("poison")) {
          
            if (args.length == 0) {
                return true;
            }
          
            Integer x = Integer.valueOf(args[0]);
            if (p.getItemInHand().getType() == Material.DIAMOND_SWORD) {
                p.setItemInHand(settings.Poison(Material.DIAMOND_SWORD, getint(x)));
                return true;
            }
        }
        if (cmd.getName().equalsIgnoreCase("poison1")) {
            p.setItemInHand(settings.Poison1(p.getItemInHand().getType()));
            return true;
        }
        if (cmd.getName().equalsIgnoreCase("poison2")) {
            p.setItemInHand(settings.Poison2(Material.DIAMOND_SWORD));
            return true;
        }
      
        return true;
    }
  
    public static String getint(int args) {
        if (args == 1) return "I";
        if (args == 2) return "II";
        if (args == 3) return "III";
        if (args == 4) return "IV";
        if (args == 5) return "V";
        if (args == 6) return "VI";
        if (args == 7) return "VII";
        if (args == 8) return "VIII";
        if (args == 9) return "IX";
        if (args == 10) return "X";
        if (args == 11) return "XI";
        if (args == 12) return "XII";
        return args+"";
        }
  
  
  

}

 

@Albkad
Just put a try catch around the Integer.parseInt().

Code:java

try {
    Integer.parseInt(...)
} catch (NumberFormatException e) {
 
}

 

@AlvinB So I Tried This But I Got To Return An Int And If I Say 0 Then It The Lore Changes Into Poison 0. I Need It To Just Stop The Code.

Code:

    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {
       
        if (!(sender instanceof Player)) return true;
        Player p = (Player) sender;
       
        if (cmd.getName().equalsIgnoreCase("poison")) {
           
            if (args.length == 0) {
                return true;
            }
            if (p.getItemInHand().getType() == Material.DIAMOND_SWORD) {
                p.setItemInHand(settings.Poison(Material.DIAMOND_SWORD, getint(changeInt(args[0]))));
                }
                return true;
            }
        if (cmd.getName().equalsIgnoreCase("poison1")) {
            p.setItemInHand(settings.Poison1(p.getItemInHand().getType()));
            return true;
        }
        if (cmd.getName().equalsIgnoreCase("poison2")) {
            p.setItemInHand(settings.Poison2(Material.DIAMOND_SWORD));
            return true;
        }
       
        return true;
    }
   
    public static String getint(int args) {
        if (args == 1) return "I";
        if (args == 2) return "II";
        if (args == 3) return "III";
        if (args == 4) return "IV";
        if (args == 5) return "V";
        if (args == 6) return "VI";
        if (args == 7) return "VII";
        if (args == 8) return "VIII";
        if (args == 9) return "IX";
        if (args == 10) return "X";
        if (args == 11) return "XI";
        if (args == 12) return "XII";
        return args+"";
        }
    public int changeInt(String arg) {
        try {

            return Integer.parseInt(arg);

        } catch (NumberFormatException e) {

         return 0;

        }
    }


   
   

}

 

if(Ints.tryParse(args[0]) == null)

 

@Edvio thx