[SOLVED] A real headache - why onCommand is crashing my server?

Hello,

What already I have done:

1) I removed all other plugin and left only mine.
2) checked the code and isolated the part that is crashing it.

I will try to make it brief and simple. I wrote a command listener - or in other way a command executor.

Code:

        //getCommand("vote").setExecutor(votecmd);

That is referring to:

Code:

    private VoteCommand votecmd;

That is referring to:

Code:

package com.zajacmp3.survivalgame;

import java.awt.List;

import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;

public class VoteCommand implements CommandExecutor {
    
    static SurvivalGame survivalgame = new SurvivalGame();
    static List votersList = new List();

    public boolean onCommand(CommandSender sender, Command cmd, String cmdLabel, String[] args) {
        Player player = (Player) sender;
        if(cmdLabel.equalsIgnoreCase("vote") && SurvivalGame.hasVotingStarted){
            if(player.hasPermission("survivalgame.vote")){
                int howManyMaps = SurvivalGame.config.getInt("MapConfiguration.HowManyMaps");
                if(Integer.parseInt(args[0])<=howManyMaps && Integer.parseInt(args[0])>=howManyMaps && haveHeVoted(player)!=true){
                    votersList.add(player.getName());
                    SurvivalGame.voteMapList[1][Integer.parseInt(args[0])] = SurvivalGame.voteMapList[1][Integer.parseInt(args[0])+1];
                }
            }
            else{
                player.sendRawMessage("You do not have permission to do this");
            }
        }
        else{
            player.sendRawMessage("Voting for another map have not started yet");
        }
        return false;
    }

    private boolean haveHeVoted(Player player) {
        if(votersList.equals(player.getName())){
            return true;
        }
        else
            return false;
    }

}

Error on crash that I get is:

Code:

---- Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 8/8/12 10:51 AM
Description: Exception in server tick loop

java.lang.NullPointerException
    at org.bukkit.craftbukkit.help.SimpleHelpMap.initializeCommands(SimpleHelpMap.java:120)
    at org.bukkit.craftbukkit.CraftServer.enablePlugins(CraftServer.java:255)
    at net.minecraft.server.MinecraftServer.i(MinecraftServer.java:296)
    at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:275)
    at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:225)
    at net.minecraft.server.DedicatedServer.init(DedicatedServer.java:140)
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:380)
    at net.minecraft.server.ThreadServerApplication.run(SourceFile:539)

Relevant Details:
- Minecraft Version: 1.3.1
- Operating System: Linux (amd64) version 2.6.18-238.12.1.el5.028stab091.1
- Java Version: 1.6.0_24, Sun Microsystems Inc.
- Java VM Version: OpenJDK 64-Bit Server VM (mixed mode), Sun Microsystems Inc.
- Memory: 889009648 bytes (847 MB) / 1037959168 bytes (989 MB) up to 1037959168 bytes (989 MB)
- JVM Flags: 2 total; -Xmx1024M -Xms1024M
- Type: Dedicated Server
- Is Modded: Definitely; 'craftbukkit'
- Profiler Position: N/A (disabled)
- Player Count: 0 / 20; []
- World Lobby Entities: 0 total; []
- World Lobby Players: 0 total; []
- World Lobby Chunk Stats: ServerChunkCache: 625 Drop: 0

What I think I done wrong:

1) Bad code writing in VoteCommand class that is making NullPointerExeption.

What I need help with:

1) locating my mistake
2) help me find a way to get it working

 

It sounds like votecmd is null. Post the code surrounding "//getCommand("vote").setExecutor(votecmd);"

 

Here you are. Everything there can be relevant surrounding.

Code:

public class SurvivalGame extends JavaPlugin implements Listener{
 
    static Counters counters = new Counters();
    static SurvialListeners survivallisteners = new SurvialListeners();
    static SurvivalGame plugin;
 
    //static things
    static int prebattlelenght = 5;
    static int battlelenght = 5;
    static int minimumnumberofplayers = 2;
    static int tempcountdown = 0;
    static int countdownTask = 0;
    static int blockMovement = 0;
    static boolean haveBattleStarted = false;
    static boolean hasVotingStarted = false;
    static int[][] voteMapList = new int[1][];
    static int nextMap = 1;
    //List of Players that started Battle
    static List<String> listOfQualifiedPlayers = new ArrayList<String>();
    static FileConfiguration config = null;
 
    public void onDisable(){
        this.getServer().getScheduler().cancelAllTasks();
    }
    public void onEnable(){
        System.out.println("Test1");
        getCommand("vote").setExecutor(votecmd);
        System.out.println("Test2");
 
        plugin = this;
        config = this.getConfig();
        loadConfig();
        prepareBattle();
    }
[...] Nothing relevant to commands after this

When I was writing this command and all I was guided by a tutorial on how to write commands
Source: http://forums.bukkit.org/threads/prefixed-commands-tutorial-organization.61890/

@EDIT:

I really don't have a clue how to properly write commands yet. I though that I made everything right going by the tutorial. If I won't be able to solve this I will have to go through hundreds lines of code on git hub of other developers to get their idea. And I really hope to avoid it...

Okay, I have to double post...

I solved it.

How I did it? I was patiently reading Plugin Development and helping where I could waiting for an answer. And it came in another topic written by bitfreeze - Thanks.

So I changed my code:

Code:

getCommand("vote").setExecutor(votecmd);

to:

Code:

getCommand("vote").setExecutor(new VoteCommand());

And I get different error:

Code:

Caused by: java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
        at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:173)
        at java.awt.List.<init>(List.java:233)
        at java.awt.List.<init>(List.java:188)
        at com.zajacmp3.survivalgame.VoteCommand.<clinit>(VoteCommand.java:13)
        ... 17 more

So I changed in 13 line of VoteCommand class:
From

Code:

static List votersList = new List();

to:

Code:

static ArrayList<String> votersList = new ArrayList<String>();

and it is working.

Thanks everybody for even slightest interest in this topic.

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