ChatListener:
package hu.dchatdisable;

import org.bukkit.event.player.*;
import org.bukkit.*;
import org.bukkit.event.*;

public class ChatListener implements Listener
{
    String chatprefix;

    public ChatListener() {
        this.chatprefix = "§8[§fHyper§bSide§8] §7» ";
    }

    @EventHandler
    public void onChat(final AsyncPlayerChatEvent event) {
        if (!Cmd.chat) {
            if (event.getPlayer().hasPermission("dchatdisable.chat.bekapcs")) {
                return;
            }
            event.getPlayer().sendMessage(String.valueOf(this.chatprefix) + ChatColor.RED + "Jelenleg a kommunik\u00e1ci\u00f3 nem enged\u00e9lyezett!");
            event.setCancelled(true);
        }
    }
}



Cmd:

package hu.dchatdisable;

import org.bukkit.command.*;
import org.bukkit.entity.*;
import org.bukkit.*;

public class Cmd implements CommandExecutor
{
    String chatprefix;
    public static boolean chat;

    public Cmd() {
        this.chatprefix = "§8[§fHyper§bSide§8] §7» ";
    }

    public boolean onCommand(final CommandSender sender, final Command cmd, final String commandLabel, final String[] args) {
        if (!(sender instanceof Player)) {
            sender.sendMessage(ChatColor.RED + "Nincs jogod ehhez!");
            return true;
        }
        final Player player = (Player)sender;
        if (!player.hasPermission("dchatdisable.chat")) {
            player.sendMessage(ChatColor.RED + "Nincs enged\u00e9lyed a parancs haszn\u00e1lat\u00e1hoz!");
            return true;
        }
        if (Cmd.chat) {
            Cmd.chat = false;
            player.sendMessage(String.valueOf(this.chatprefix) + ChatColor.GRAY + "A Chat jelenleg ki van kapcsolva, ez\u00e9rt senki sem tud \u00edrni.");
        }
        else {
            Cmd.chat = true;
            player.sendMessage(String.valueOf(this.chatprefix) + ChatColor.GREEN + "Mostm\u00e1r mindenki tud \u00edrni. A chat be lett kapcsolva.");
        }
        return true;
    }
}



Main:

package hu.dchatdisable;

import org.bukkit.plugin.java.*;
import org.bukkit.event.*;
import org.bukkit.command.*;
import org.bukkit.plugin.*;

public class main extends JavaPlugin implements Listener, CommandExecutor
{
    public void onEnable() {
        final PluginDescriptionFile pdfFile = this.getDescription();
        System.out.println("[" + pdfFile.getName() + "] v" + pdfFile.getVersion() + " A plugin sikeresen elindult! Author: " + pdfFile.getAuthors());
        this.getServer().getPluginManager().registerEvents((Listener)new ChatListener(), (Plugin)this);
        this.getCommand("chat").setExecutor((CommandExecutor)new Cmd());
    }

    public void onDisable() {
        final PluginDescriptionFile pdfFile = this.getDescription();
        System.out.println("[" + pdfFile.getName() + "] v" + pdfFile.getVersion() + " A plugin sikeresen leallt! Author: " + pdfFile.getAuthors());
    }
}