java.lang.IllegalArgumentException: Name cannot be null

I'm getting this error:

Code:

java.lang.IllegalArgumentException: Name cannot be null

from this class when calling the start game method

Code:java

package mcadventure.hunt;
 
import java.awt.List;
import java.util.HashMap;
import java.util.Random;
 
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.entity.Player;
 
public class HuntArena {
 
    HashMap<Integer, String> playing = new HashMap<Integer, String>();
 
    public enum Team{
        Hunt, Prey
    }
 
    public enum GameState{
        Lobby, FirstFive, Hunt, EndGame
    }
 
    public HashMap<String, Team> aliveplayers = new HashMap<String, Team>();
    int number = 0;
    GameState gs = GameState.Lobby;
    boolean pvp;
    int id = 1;
    HuntMessenger message = new HuntMessenger();
 
    public void setGameState(GameState game){
        gs = game;
    }
 
    public GameState getGameState(){
        return gs;
    }
 
    public int getId(){
        return id;
    }
 
    public void startGame(){
        gs = GameState.FirstFive;
        if(aliveplayers.size() < 0){
            for(Player plr : Bukkit.getServer().getOnlinePlayers()){
                plr.kickPlayer(ChatColor.RED + "Not enough prey D:");
            }
            Bukkit.getServer().dispatchCommand(Bukkit.getConsoleSender(), "reload");
          }
    Random ra = new Random();
    List hunterlist = new List();
    int hunters = (playing.size() + 1) / 5 + 1;
    try{while(hunters != 0){
        String plr = Bukkit.getServer().getPlayer(playing.get(ra.nextInt())).getName();
        Bukkit.broadcastMessage(plr);
        hunters--;
      }
    message.BroadCast("The Game Has Begun, The Hunters are " + hunterlist);
    }catch(Exception e){
        Bukkit.broadcastMessage(e.toString());
    }
    }
    public void addPlaying(String name){
        playing.put(number, name);
    }
 
    public void addPlayer(String str, Team t){
        aliveplayers.remove(str);
        aliveplayers.put(str, t);
    }
 
    public void removePlayer(String str){
        aliveplayers.remove(str);
    }
 
    public Team getTeam(String s){
        return aliveplayers.get(s);
    }
 
    public boolean getPvP(){
        return pvp;
    }
    public void setPvP(Boolean b){
        pvp = b;
    }
}

I really don't understand the error or whats causing it

 

Don't do this:

Code:

catch(Exception e){
    Bukkit.broadcastMessage(e.toString());
}

Do this instead:

Code:

catch(Exception e){
    e.printStackTrace();
}

It will print out a more detailed error message,mainly including the line the error is coming from. But since that already narrows it down to 3 possible lines (inside the try block), it's probably this one:

Code:java

 
String plr = Bukkit.getServer().getPlayer(playing.get(ra.nextInt())).getName();
 

There's no guarantee that random.nextInt() will be below the size of the list. In fact, its upper limit is 2,147,483,647. However, you can set the value's upper limit yourself like this:

Code:java

 
ra.nextInt(5)
//Random number between 0 and 4 (inclusive)
 
ra.nextInt(playing.size())
//Random number within the size of the list
 

 

adam753
Oh yeah forgot to set thwe nextint max to player total xD