How to test hashmap players/ send messages to hashmap players

Hi, I was wondering how you would check to see how many players are in a hashmap, and how to send messages only to the players in the hashmap.

 

map.entrySet()

 

I need a little more information than that..

 

Bukkit.getPayer(string).sendMessage()
map.entrySet().size()
Really its not hard at all.

 

t says map can not be resolved, and do I put the plugin.hashmap replacing String? How do I only broadcast messages to people in the hashmap?

Hi, I was wondering how you would check to see how many players are in a hashmap, and how to send messages only to the players in the hashmap.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

SeanyJo
That's because by 'map' he means your map, whatever its name is. Then you loop through yourMap.keyset(), and for every String in there (assuming it is <String, ???>, .sendMessage() to Bukkit.getPlayerExact(theStringFromTheLoop);

 

Code:java

 
size = hashmap.entrySet().size();
for(String s : hashmap.keySet()){
    Player p : Bukkit.getPlayer(s);
    s.sendMessage(...);
}
 

 

@SeanyJo

Use something like this:

Code:

 
for(Entry<//first thing in your hashmap, //secondthing in your hashmap > pl : //hashmapname.entrySet()){
    pl.getKey().sendMessage("HELLO!");
 
}

Hope its clear

 

Bukkit.getPlayer(string).sendMessage(ChatColor.GREEN + "HI!");

plugin.hashmap.entrySet().size();
thats what I have so far, and I still don't get the string thing, and I don't know if every other part of this is correct or not.

 

Except you wouldn't be storing a player variable.

 

SeanyJo
Maps and ArrayLists have a .size() method, which returns an integer of the map or list size. Could you show me what your map looks like, then elaborate your question?

Edit: your questions have already been answered here: http://forums.bukkit.org/threads/ho...yers-send-messages-to-hashmap-players.174400/

 

Do (if your hashmap is called players) players.getKeys();
then just do a for loop through them and send the message.

 

tommycake50

You can fix it like this (or not, I am not sure){

Code:

for(Entry<Player, //secondthing in your hashmap > pl : //hashmapname.entrySet()){
pl.getKey().sendMessage("HELLO!");
 
}

 

I don't get it, I'll paste a copy of my Executor.
http://pastebin.com/ujWPBJxj

 

One thing Never EVER store player instances(EVER)!

 

I don't get that..
I'm a beginner in Java also.

 

tommycake50

Sorry, I am also quite new in developing plugins(3 months or so), but could you please explain it why I shouldn't do that?

thnx!

 

Well, if you have an instance of a player, Java's garbage collection cant finalize and destroy the instance so that means all the loaded chunks that it has loaded, all the plugins that use that player etc, etc will still think the player exists rather than the player leaving and no further calls being made to it so the garbage collector disposes of it and cleans up properly that doesn't happen and you'll probably get problems because of it(Not to mention it causes a memory leak so it wastes RAM).
Essentially it just locks things up in a bad way.
So by having a player in your list the garbage collector can't get rid of it because calls can be made to lists maps and RAM stored mediums at any time so its not fit for collection.

 

are you talking to me or OracleTarget?

 

You both really need to know that.

 

How could I fix this problem?

 

Store string objects and use Bukkit.getPlayerExact().

 

Where would I put that? Sorry, i'm a beginner in Bukkit and Java API

Or, could I make an event on Player Quit where they leave the hashmap on certain commands and leaving the server?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

No, that's bad coding practice.
But you can remove their name on command and leaving the server .

 

How would I do that?

 

map.remove(player.getName());

 

Many people active on the forums have a signature explaining why you should never include player instances inside a hashmap. It can lead to memory leaks, lag, and is an overall bad coding practice in general. Use player.getName() store it in a hashmap and for loop for players and get 1 player at a time and send message to said player.

 

This code below is an example of sending players in a HashMap a message using their stored names.

Code:java

public HashMap<String, Integer> examplePlayerMap = new HashMap<String, Integer>();
//The integer is just an example as I'm not sure what your values are for the keys in the HashMap
 
public void tellPlayersInMap(String message) {
    for (String playerName : examplePlayerMap.keySet()) {
        Player player = Bukkit.getPlayerExact(playerName);
        if (player != null) {
            player.sendMessage(message);
        }
    }
}
 
//This is an example usage of the tellPlayersInMap() method
tellPlayersInMap("Hey! You're in a HashMap.");

 

Would the tellPlayersInMap be replaced with anything? My hashmap name is hashmap.

 

You can change the name of the method to anything you want. All you have to do is replace the examplePlayerMap (the name of my example HashMap) to the name of your HashMap. (If you want that method to be even more versatile you could add a HashMap parameter and specify which HashMap's keys the method will iterate through.)