ERROR!
[SEVERE] null
org.bukkit.command.CommandException: Unhandled exception executing command 'ban' in plugin MinecraftRP v0.1
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
	at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
	at org.bukkit.craftbukkit.v1_4_R1.CraftServer.dispatchCommand(CraftServer.java:514)
	at net.minecraft.server.v1_4_R1.PlayerConnection.handleCommand(PlayerConnection.java:980)
	at net.minecraft.server.v1_4_R1.PlayerConnection.chat(PlayerConnection.java:898)
	at net.minecraft.server.v1_4_R1.PlayerConnection.a(PlayerConnection.java:853)
	at net.minecraft.server.v1_4_R1.Packet3Chat.handle(Packet3Chat.java:44)
	at net.minecraft.server.v1_4_R1.NetworkManager.b(NetworkManager.java:290)
	at net.minecraft.server.v1_4_R1.PlayerConnection.d(PlayerConnection.java:113)
	at net.minecraft.server.v1_4_R1.ServerConnection.b(SourceFile:39)
	at net.minecraft.server.v1_4_R1.DedicatedServerConnection.b(SourceFile:30)
	at net.minecraft.server.v1_4_R1.MinecraftServer.r(MinecraftServer.java:598)
	at net.minecraft.server.v1_4_R1.DedicatedServer.r(DedicatedServer.java:224)
	at net.minecraft.server.v1_4_R1.MinecraftServer.q(MinecraftServer.java:494)
	at net.minecraft.server.v1_4_R1.MinecraftServer.run(MinecraftServer.java:427)
	at net.minecraft.server.v1_4_R1.ThreadServerApplication.run(SourceFile:849)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 0
	at me.kreashenz.minecraftrp.Commands.Ban.onCommand(Ban.java:23)
	at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
	... 15 more
CODE:
package me.kreashenz.minecraftrp.Commands;

import java.io.File;

import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.configuration.file.YamlConfiguration;
import org.bukkit.entity.Player;

public class Ban implements CommandExecutor{

	@Override
	public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
		File file = new File( "plugins/MinecraftRP/config.yml" );
		FileConfiguration config = YamlConfiguration.loadConfiguration(file);
		String prefix = config.getString("prefix");
		if(cmd.getName().equalsIgnoreCase("ban")){
			if(sender instanceof Player){
				if(sender.hasPermission("mrcp.ban")){
			    **LINE 23** Player target =Bukkit.getServer().getPlayerExact(args[]);
					target.setBanned(true);
					Bukkit.broadcastMessage(prefix + sender + " banned player :" + args[0]);
				}
			}
		}
		return false;
	}
}