Using AsyncPlayerPreLoginEvent to kick a banned player

Hello everyone,

I'm having a little bit of trouble today trying to "kick" a banned player. I'm reading from a ban list, this is how the ban list looks like:

Code:

banlist:
  notch:
    reason: ' you are thirsty'
  thecontroller:
    reason: ' you are hungry'

How would I go on about doing this?

 

hello Th3Controller,
1. onEnable: load the Config and get a list of all banned players. (or an HashMap<String, String> Name , Reason)
2. onPlayerLogin: check if the player is in the hashmap / list if he is kick him

if you need a sample code message / tag me ;3

 

I already have the config.yml loaded, the list gets read when a player pre-login event occurs.

I prefer to use AsyncPlayerPreLoginEvent. Also don't prefer to use HashMaps in this occassion :3

 

I'm not entirely sure about this, but it may be better to use synchronized class in Async event, like Hashtable.

Edit: wait, are you having troubles with kicking the player ?

 

ok but it's a performance loss if you read the list every time a players Join's try to cache the data.

 

No I need help setting it up, I tried doing it yes but it didn't work.

Good idea, I'll just cache/add the a attempting player that's already banned into a HashMap/ArrayList. so whenever he tries to spam join it won't be a performance lost

 

As it is an Async event, mind thread-safety

 

What do you mean by "mind thread-safety".
Is this method unsafe? Should I use a different method using the main thread instead?

 

No, I mean that you should mind how you access Lists/Sets/HashMaps across threads. One way to go about it is handling Concurrency yourself using synchronized blocks/the synchronized keyword. Or use a CopyOnWriteArrayList

 

use PlayerPreLoginEvent.
and
if they are banned.
event.disAllow(event.result.KICK_BANNED, message);

 

Are you sure?

If someone can whip up a batch of code that would help, I'm having the trouble of reading from the file also (not that the plugin can't read it, I don't know how to read it).

 

Why not use the PlayerLoginEvent? Nonetheless if you want a thread-safe method:
The config

Code:

default-reason: You have been banned!
Banned:
  - Playername;reason

The HashMap

Code:java

java.util.concurrent.ConcurrentHashMap<String, String> banned = new java.util.concurrent.ConcurrentHashMap<String, String>();
 

The onEnable()

Code:java

public void onEnable()
{
    List<String> banList = getConfig().getStringList("Banned");
    if(banList == null)
    {
        banList = new ArrayList<String>();
        getConfig().set("Banned", banList);
        saveConfig();
    }
    for(String bannedPlayer : banList)
    {
        String[] pr = bannedPlayer.split(";", 2);
        if(pr.length == 0)
        {
            continue;
        }
        if(pr.length == 1)
        {
            pr = new String[]{pr[0], getConfig().getString("default-reason", "You have been banned")};
        }
        banned.put(pr[0], pr[1]);
    }
}

The event:

Code:java

@EventHandler(priority=EventPriority.HIGHEST)
public void onPreLogin(AsyncPlayerPreLoginEvent event)
{
    String name = event.getName();
    if(banned.containsKey(name))
    {
        String reason = banned.get(name);
        event.disallow(AsyncPlayerPreLoginEvent.Result.KICK_BANNED, reason == null ? "You have been banned" : reason);
    }
}

 

fireblast709 Lol that was my old format for the player and reason. But my friend had to tell me its better that way >.>. Anyways I'll continue with yours, I'll be back later or tomorrow on my result, I'm tired.

Btw you made making a config file look intimidating.

Why not use (making this on the top of my head, I forgot)
getConfig.CopyDefaults(true);
saveConfig;

 

Yea you could obviously use a default here ;3. And if your friend is talking about the async part, he has a point there
(as that part of the code would be executed on another thread and would not directly interfere with the main threads execution flow).

Sorry for the intimidating code xD

 

not that it would matter too much and theres a low risk but nonetheless i agree with you its bad practice anyway.

 

Wait I don't follow you there xD