Solved Need Help With Arguments

The problem is that when I do /fly, I get and internal error, but if I do /fly player then it works fine. This problem is in some of my commands, but not all. Here is my code:

Code:

package me.tag.personal;

import java.util.ArrayList;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;

public class Fly implements CommandExecutor {

    ArrayList<String> fly = new ArrayList<String>();

    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {

        Player p = (Player) sender;
        Player t = Bukkit.getServer().getPlayer(args[0]);

        if (cmd.getName().equalsIgnoreCase("fly")) {


            if (args.length == 0) {

                if (fly.contains(p.getName())) {

                    p.setAllowFlight(false);
                    p.sendMessage(ChatColor.GREEN + "You are now unable to fly!");
                    return true;

                }

                fly.add(p.getName());
                p.sendMessage(ChatColor.GREEN + "You are now able to fly!");
                return true;
            }
            fly.add(p.getName());
            p.setAllowFlight(true);
            p.sendMessage(ChatColor.GREEN + "Fly is now Enabled!");
            return true;
        }
        if (t == null) {
            p.sendMessage(ChatColor.RED + "Player " + args[0] + " could not be found!");
            return true;
        } else if (fly.contains(t.getName())) {
           

                fly.remove(t.getName());
                t.setAllowFlight(false);
                p.sendMessage(ChatColor.GREEN + "Fly for " + t.getName() + " is now Disabled!");
                t.sendMessage(ChatColor.GREEN + "Fly is now Disabled!");
                return true;
            }
            fly.add(t.getName());
            t.setAllowFlight(true);
            p.sendMessage(ChatColor.GREEN + "Fly for " + t.getName() + " is now Enabled!");
            t.sendMessage(ChatColor.GREEN + "Fly is now Enabled!");
            return true;
        }
    }

 

@TheArabianCoder You need to check the args.length

Code:

// When the don't put args:
if(args.length == 0) {
// Do Stuff

// When you check for player args:
if(args.length == 1) {
// Do Stuff

 

Check before casting!

Code:

if (sender instanceof Player) {
    //Code
}

You don't want the console to be able to execute this command either, as it is setting flight.

 

I would opt for the negative check instead and return. This allows for the rest of your code to not have to be inside so many if-statements making it easier to read. Only do that if you need one particular functionality though.

 

They didn't work

 

@TheArabianCoder, you are getting an player from your argument before actually checking if your argument exists.

Code:

Player t = Bukkit.getServer().getPlayer(args[0]);
//is basically when there's no argument
Player t = Bukkit.getServer().getPlayer(null);
//which obviously throws null exception

 

Thanks @SyTeck, it works now!