CommandX

import java.util.HashMap;
import java.util.Iterator;

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

public class CommandX implements CommandExecutor {

    private HashMap<Location, Material> blocks = new HashMap<Location, Material>();
    private boolean drawn = false;

    @Override
    public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
        if(!(sender instanceof Player)) return true;
        Player plr = (Player) sender;

        if(drawn == false){
            for(int X = plr.getLocation().getBlockX() - 50; X < plr.getLocation().getBlockX() + 50; X++){
                if(X >= plr.getLocation().getBlockX() - 2 && X <= plr.getLocation().getBlockX() + 2) continue;
                Location l = new Location(plr.getWorld(), X, plr.getLocation().getBlockY(), plr.getLocation().getBlockZ());
                blocks.put(l, l.getBlock().getType());
                l.getBlock().setType(Material.GLASS);
            }

            for(int Y = plr.getLocation().getBlockY() - 50; Y < plr.getLocation().getBlockY() + 50; Y++){
                if(Y >= plr.getLocation().getBlockY() - 2 && Y <= plr.getLocation().getBlockY() + 2) continue;
                if(Y < 0) Y = 0;
                Location l = new Location(plr.getWorld(), plr.getLocation().getBlockX(), Y, plr.getLocation().getBlockZ());
                blocks.put(l, l.getBlock().getType());
                l.getBlock().setType(Material.GLASS);
            }

            for(int Z = plr.getLocation().getBlockZ() - 50; Z < plr.getLocation().getBlockZ() + 50; Z++){
                if(Z >= plr.getLocation().getBlockZ() - 2 && Z <= plr.getLocation().getBlockZ() + 2) continue;
                Location l = new Location(plr.getWorld(), plr.getLocation().getBlockX(), plr.getLocation().getBlockY(), Z);
                blocks.put(l, l.getBlock().getType());
                l.getBlock().setType(Material.GLASS);
            }
        }else{
            Iterator<Location> i = blocks.keySet().iterator();
            while(i.hasNext()){
                Location l = i.next();
                l.getBlock().setType(blocks.get(l));
                i.remove();
            }
            blocks.clear();
        }

        drawn = !drawn;

        return true;
    }

}