DrugsMain.java:

package me.stress.drugs;

import org.bukkit.plugin.java.JavaPlugin;

import me.stress.drugs.commands.DrugsCommand;
import me.stress.utils.Common;

public class DrugsMain extends JavaPlugin {

	public static DrugsMain instance;

	@Override
	public void onEnable() {
		Common.registerCommand(new DrugsCommand());
	}

	@Override
	public void onDisable() {
		instance = null;
	}

	public static DrugsMain getInstance() {
		return instance;
	}

}


DrugsCommand.java:

package me.stress.drugs.commands;

import java.util.Arrays;

import org.bukkit.Bukkit;
import org.bukkit.Material;
import org.bukkit.command.CommandSender;
import org.bukkit.command.defaults.BukkitCommand;
import org.bukkit.entity.Player;
import org.bukkit.inventory.ItemStack;

import me.stress.utils.Common;

public class DrugsCommand extends BukkitCommand {

	public DrugsCommand() {
		super("drugs");

		setAliases(Arrays.asList("drug", "d"));
		setDescription("This is a basic Drugs core");
	}

	@Override
	public boolean execute(CommandSender sender, String commandLabel, String[] args) {

		if (!sender.hasPermission("drugs.use")) {
			Common.tell(sender, "&cYou do not have permission to use this command!");

			return true;
		}

		if (!sender.hasPermission("drugs.admin")) {
			Common.tell(sender, "&cYou do not have permission to use this command!");

			return true;
		}

		if (sender.hasPermission("drugs.use")) {
			if (args.length == 1) {
				if (args[0].equalsIgnoreCase("help")) {
					Common.tell(sender, "&8&m--------------------------------------------");
					Common.tell(sender, " &f/drugs help - Shows the help message");
					Common.tell(sender, " &f/drugs give - Gives a specified player drugs");
					Common.tell(sender, " &f/example - Example command");
					Common.tell(sender, " &aThis plugin was created by Stress_");
					Common.tell(sender, "&8&m--------------------------------------------");
				}
			}

		}

		if (sender.hasPermission("drugs.admin")) {
			if (args.length == 2) {
				if (args[0].equalsIgnoreCase("give")) {
					final Player target = Bukkit.getPlayer(args[1]);
					target.getInventory().addItem(new ItemStack(Material.WHEAT));
					Common.tell(sender, "&aYou have given drugs to " + args[1]);

					if (args[1] == null) {
						Common.tell(sender, "&cThe specified player is not online!");
						return true;
					}
				}
			}

			if (args.length < 1) {
				Common.tell(sender, "&8&m--------------------------------------------");
				Common.tell(sender, " &f/drugs help - Shows the help message");
				Common.tell(sender, " &f/drugs give - Gives a specified player drugs");
				Common.tell(sender, " &f/example - Example command");
				Common.tell(sender, " &aThis plugin was created by Stress_");
				Common.tell(sender, "&8&m--------------------------------------------");
				return true;
			}
		}

		return true;

	}
}


Common.java:

package me.stress.utils;

import java.lang.reflect.Field;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.CommandMap;
import org.bukkit.command.CommandSender;
import org.bukkit.command.defaults.BukkitCommand;

public class Common {

	public static void tell(CommandSender toWhom, String... messages) {
		for (final String message : messages)
			tell(toWhom, message);
	}

	public static void tell(CommandSender toWhom, String message) {
		toWhom.sendMessage(colorize(message));
	}

	public static String colorize(String message) {
		return ChatColor.translateAlternateColorCodes('&', message);
	}

	public static void registerCommand(BukkitCommand command) {
		try {
			final Field commandMapField = Bukkit.getServer().getClass().getDeclaredField("commandMap");
			commandMapField.setAccessible(true);

			final CommandMap commandMap = (CommandMap) commandMapField.get(Bukkit.getServer());
			commandMap.register(command.getLabel(), command);
		} catch(final Exception e) {
			e.printStackTrace();
		}
	}

}


plugin.yml:

name: Drugs
main: me.stress.drugs.DrugsMain
version: 1.0.0
author: Stress_