Bukkit

package minicraft.commands;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.permissions.Permission;
import org.bukkit.plugin.java.JavaPlugin;

public class Nickname extends JavaPlugin implements Listener {

public String prefix;

    public void onEnable() {
        prefix = ChatColor.translateAlternateColorCodes('&', "&b[&eMinicraft&b] ");
        Bukkit.getPluginManager().registerEvents(this, this);
    }
    
    public void onDisable() {}

    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {
        if (cmd.getName().equalsIgnoreCase("changename")) {
            if (sender.hasPermission("minicraft.command.changename") || sender.hasPermission("minicraft.command.nick") || sender.isOp()) {
                Player p = (Player)sender;
                if (args.length == 1) {
                    if (args[0] == "clear") {
                        p.setDisplayName(p.getName());
                    } else {
                        String name = ChatColor.translateAlternateColorCodes('&', args[0]);
                        if (sender.hasPermission("minicraft.admin") || sender.isOp()) {
                            p.setDisplayName(name);
                        } else {
                            p.setDisplayName("~" + name);
                        }
                        if (sender.hasPermission("accentials.command.nick") || sender.isOp()) {
                            p.sendMessage(prefix + "Your nickname has been set!");
                            p.sendMessage(prefix + ChatColor.RED + "You should use /nick This is only a replacement for people who don't have /nick.");
                        } else {
                            p.sendMessage(prefix + "Your nickname has been set!");
                        }
                    } 
                } else {
                    sender.sendMessage(prefix + ChatColor.RED + ChatColor.BOLD + "Error!");
                }
            } else {
                sender.sendMessage(prefix + ChatColor.RED + ChatColor.BOLD + "You don't have permission!");
            }
        return false;
        }
    return false;  
    }
}