Bukkit timer using schedulers

So I know theres about a billion of this posts, but i'm finding a hard time understanding the schedulers. What i'm trying to do in the code below is create a 30 second timer. Any help either explaining what i did wrong or even just explaining the code would be appreciated.

Code:

int taskid = this.getServer().getScheduler().scheduleSyncRepeatingTask(this, new Runnable() {
public void run() {
        if(number != -1) {
            number--;
            if(number == 30) {
                Bukkit.broadcastMessage(ChatColor.GOLD + "30 seconds left!");
            } else if(number == 15) {
                Bukkit.broadcastMessage(ChatColor.GOLD + "15 seconds left!");
            } else if(number <= 10 && number > 0){
                Bukkit.broadcastMessage("" + ChatColor.GOLD + number + " seconds left!");
            }
        } else {
            Bukkit.getServer().getScheduler().cancelTask(taskid);
            Bukkit.broadcastMessage("Done");
            number--;
            return;
        }
    }
}, 0L, 20L);

 

I would normally do something along the lines of:

Code:

            for (final Player p : Bukkit.getServer().getOnlinePlayers()) {
                Bukkit.getServer().getScheduler().scheduleSyncRepeatingTask(Core.getPlugin(), new Runnable() {
                    @Override
                    public void run() {
                        if (number == 30 || number == 15 || number <= 10 && number >0) {
                            p.sendMessage(ChatColor.GOLD + "" + number + " seconds left!");
                        }
                        if (number == 0) {
                            p.sendMessage("Done");
                            return;
                        }
                        if (number > 0) {
                            number--;
                        }
                    }
                }, 10L, 20L);
            }

 

your code is more or less right. The only problem is this: ...}, 0L, 20L); here you say to the timer to run every 20 ticks. (1 second = 20 ticks) so to fix it, simply put yourminutes*60*20 there.

 

No, mine-care. Look better.

Prorockband ->
Did you initialize "number" ? Where is it initialized ? At which value ? Is it final ?

Also instead of (number != -1) I'd use (number != 0).

Also error messages would help us determine what's wrong.