gistfile1.java

lastHit.put(victim.getName(), attacker.getName());
final Player vic = victim.getPlayer();
final BukkitScheduler scheduler = Bukkit.getScheduler();
if (lastHitId.containsKey(vic.getName())) {
	int taskId = lastHitId.get(vic.getName());
	if (scheduler.isCurrentlyRunning(taskId)) {
		scheduler.cancelTask(taskId);
	}
}
BukkitTask task = scheduler.runTaskLater(plugin, new BukkitRunnable() {
	@Override
	public void run() {
		lastHit.remove(vic.getName());
	}
}, 300);
lastHitId.put(vic.getName(), task.getTaskId());