public boolean onCommand(CommandSender sender, Command cmd, String arg2, String[] args) {
if(sender instanceof Player){
if(cmd.getName().equalsIgnoreCase("showHidden")){
HashMap<Player,Integer> hiddenplayers = new HashMap<>(); // Key: Player, Value: Remaining time of Effect in seconds
for (Player p: getServer().getOnlinePlayers()) {
if(p.hasPotionEffect(PotionEffectType.INVISIBILITY)) {
int duration = p.getPotionEffect(PotionEffectType.INVISIBILITY).getDuration()/20; // Divide with 20 -> Convert from ticks to seconds
hiddenplayers.put(p, duration);
}
}
//PRINT ANYHOW for example as following
for (Player p: hiddenplayers.keySet()) {
sender.sendMessage(p.getName()+ "("+hiddenplayers.get(p)+"s)");
}
}
}
return true;
}