Cancelling a scheduled repeater on Bukkit/Java

Question

I am programming a plugin that records the coordinates of players in minecraft throughout the game, in Java with Bukkit API.

I have used a 'repeating task' structure in my bukkit/java code below.

However, I need to 'cancel' this repeating task when a particular player logs off, as otherwise, if player 'A' logs in and logs off 50 times in a row, I will have 50 running tasks.

The idea is to stop the runnable of player 'A' if and only if player 'A' logs off (and not B).

Am I right in saying that the following code will cancel the repeating task for a particular player only when that particular player logs off?

I would be so grateful for a helping hand!

   @EventHandler
    public void onLogin(final PlayerJoinEvent event) {
        final Player thePlayer = event.getPlayer();
        this.stopRepeater = true;
        final Location playerSpawnLocation = thePlayer.getLocation();
        getLogger().info(String.valueOf(thePlayer.getName()) + " is logging in!");
        getLogger().info("Welcome " + thePlayer.getName() + ". Your current position is: " + playerSpawnLocation);
        int taskID = Bukkit.getServer().getScheduler().scheduleSyncRepeatingTask(this, () -> {
            if(this.stopRepeater) {
                this.logToFile(thePlayer, thePlayer.getLocation());
            }
        }, 0L, 20L);}
    
    @EventHandler
    public void onQuit(final PlayerQuitEvent event) {
        Player thePlayer = event.getPlayer(); 
        if(!thePlayer.isOnline()) {
            this.stopRepeater = false;  
            Bukkit.getScheduler().cancelTask(taskID); 
            getLogger().info(String.valueOf(event.getPlayer().getName()) + " has left the game");
        }
    }

Answer 1

You code is actually working only for one player. You should save task object for each player with a Map.

I suggest you to use runTaskTimer to have a BukkitTask, then use like this:

HashMap<UUID, BukkitTask> tasks = new HashMap<>()

When player login:

BukkitTask task = getServer().getScheduler().runTaskTimer(this, () -> doThing(), 0, 20);
tasks.put(player.getUniqueId(), task); // add in map

Finally, when player left:

BukkitTask task = tasks.remove(player.getUniqueId()); // remove from map if exist
if(task != null) { // task found
   task.cancel();
}