Spigot Comando simples

package me.yourname.helloworld.commands;

import me.yourname.helloworld.Main;

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

public class HelloCommand implements CommandExecutor {
	
	private Main plugin;
        
    public HelloCommand(Main plugin) {
    	this.plugin = plugin;
    	plugin.getCommand("hello").setExecutor(this);
    	
    }
    
    @Override
    public boolean onCommand(CommandSender sender, Command cmd, String label,
    		String[] args) {
    	if (!(sender instanceof Player)){
    		sender.sendMessage("Only admins can use this command");
    		return true;
    	}
    	
        Player p = (Player) sender;
        
        if (p.hasPermission("hello.use")) {
        	p.sendMessage("hi!");
        	return true;
        } else{
        	p.sendMessage("You don't have perms to use this command");
        }
    	return false;
    }

}    
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simple simple simple HelloWorld command!
this is command and reply simple with spigot 1.8.8
ingame: /hello 
reply: hi!
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discord server:
https://discord.gg/tM9ANwk6