How to ensure if a player is online/exists

I have a command on my server called /coords <player> and it will tell you the coordinates of the player. The only problem is that when you input the name of a player that isn't currently online, it returns an internal error. Is there a way to check if the player is online/exists so I can return the code? Thanks

Here is the code:

Code:

        if(cmd.getName().equalsIgnoreCase("coords")){
         
            if (args.length == 1) {
             
                Player player = (Player) sender;
                Player player2 = Bukkit.getServer().getPlayer(args[0]);
                String bna = args[0].toString();
             
                if (player2 == null) return true;
             
                int x1 = (int)Math.round(Double.valueOf(player.getLocation().getX()));
                int y1 = (int)Math.round(Double.valueOf(player.getLocation().getY()));
                int z1 = (int)Math.round(Double.valueOf(player.getLocation().getZ()));
             
                int x2 = (int)Math.round(Double.valueOf(player2.getLocation().getX()));
                int y2 = (int)Math.round(Double.valueOf(player2.getLocation().getY()));
                int z2 = (int)Math.round(Double.valueOf(player2.getLocation().getZ()));
             
                double ddistance = Math.sqrt(Math.pow((x2 - x1), 2) + Math.pow((y2 - y1), 2) + Math.pow((z2 - z1), 2));
                int distance = (int)Math.round(ddistance);
             
                sender.sendMessage(ChatColor.GRAY + bna + ": " + ChatColor.YELLOW + x2 + " " + y2 + " " + z2 + " (" + distance + "m)");
                return true;
            }
         
            sender.sendMessage(ChatColor.GRAY + "Usage: " + ChatColor.YELLOW + "/coords <player>");
         
            return true;
        }

EDIT: ok it works now, I just added the if (player2 == null) return true;
I honestly didn't think that would work lol