NullPointerException

I can't figure out why this is happening. Every time I do /bq add [SOMETHING] It gives me this error:

org.bukkit.command.CommandException: Unhandled exception executing command 'bq' in plugin BasicQuiz v0.1
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46)
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:186)
at org.bukkit.craftbukkit.v1_5_R1.CraftServer.dispatchCommand(CraftServer.java:514)
at net.minecraft.server.v1_5_R1.PlayerConnection.handleCommand(PlayerConnection.java:967)
at net.minecraft.server.v1_5_R1.PlayerConnection.chat(PlayerConnection.java:885)
at net.minecraft.server.v1_5_R1.PlayerConnection.a(PlayerConnection.java:840)
at net.minecraft.server.v1_5_R1.Packet3Chat.handle(Packet3Chat.java:44)
at net.minecraft.server.v1_5_R1.NetworkManager.b(NetworkManager.java:292)
at net.minecraft.server.v1_5_R1.PlayerConnection.d(PlayerConnection.java:113)
at net.minecraft.server.v1_5_R1.ServerConnection.b(SourceFile:35)
at net.minecraft.server.v1_5_R1.DedicatedServerConnection.b(SourceFile:30)
at net.minecraft.server.v1_5_R1.MinecraftServer.r(MinecraftServer.java:580)
at net.minecraft.server.v1_5_R1.DedicatedServer.r(DedicatedServer.java:225)
at net.minecraft.server.v1_5_R1.MinecraftServer.q(MinecraftServer.java:476)
at net.minecraft.server.v1_5_R1.MinecraftServer.run(MinecraftServer.java:409)
at net.minecraft.server.v1_5_R1.ThreadServerApplication.run(SourceFile:573)
Caused by: java.lang.NullPointerException
at me.m277772.BQuiz.BQuizMain.onCommand(BQuizMain.java:56)
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
... 15 more

Heres my code:

Code:

package me.m277772.BQuiz;
 
import java.util.logging.Logger;
 
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.plugin.PluginDescriptionFile;
import org.bukkit.plugin.java.JavaPlugin;
 
public class BQuizMain extends JavaPlugin {
   
    public static BQuizMain plugin;
    public final Logger logger = Logger.getLogger("BQuiz");
    public final String[] quizName = new String[100];
    public final String[] quizQuestion1 = new String[30];
    int quizCounter = 0;
   
   
    @Override
    public void onDisable()
    {
        PluginDescriptionFile pdfFile = this.getDescription();
        this.logger.info(pdfFile.getName() + " " + pdfFile.getVersion() + " Has been disabled!");
    }
   
    @Override
    public void onEnable()
    {
        PluginDescriptionFile pdfFile = this.getDescription();
        this.logger.info(pdfFile.getName() + " " + pdfFile.getVersion() + " Has been enabled!");
    }
   
    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args)
    {
        boolean isNumber;
        Player player = (Player) sender;
        if(commandLabel.equalsIgnoreCase("bq") || commandLabel.equalsIgnoreCase("basicquiz"))
        {
            if(args.length == 0)
            {
                player.sendMessage(ChatColor.GREEN + "" + ChatColor.BOLD + "[BasicQuiz] " + ChatColor.GREEN + "Test.");
            }
            if(args.length > 0)
            {
                if(args[0].equalsIgnoreCase("add"))
                {
                    if(args.length > 1 && quizCounter < 101 && args.length < 3)
                    {
                        for(int i = 0; quizName.length > i; i++)
                        {
                            String QuizNames = quizName[i];
                            if(args.length > 1)
                            {
                                if(QuizNames.equalsIgnoreCase(args[1]))
                                {
                               
                                }else
                                {
                                    quizName[quizCounter] = args[1];
                                    quizCounter++;
                                    player.sendMessage(ChatColor.GREEN + "" + ChatColor.BOLD + "[BasicQuiz] " + ChatColor.GREEN + "A quiz named: " + ChatColor.ITALIC + args[1] + ChatColor.GREEN + "has been added.");
                                }
                            }
                        }
                    }
                }
                if(args[0].equalsIgnoreCase("sq") || args[0].equalsIgnoreCase("setquestion"))
                {
                    if(args.length > 1)
                    {
                        isNumber = true;
                        try
                        {
                            Integer.parseInt(args[1]);
                        }
                        catch(NumberFormatException e)
                        {
                            isNumber = false;
                        }
                            if(args.length > 2 && isNumber == true)
                            {
                            player.sendMessage(":D");
                            }
                    }
                }
            }
        }
       
        return false;
    }
}

Please help if possible.

 

http://forums.bukkit.org/threads/ho...ubleshoot-your-own-plugins-by-yourself.32457/
You should learn to read the errors and follow the stack trace

The problem is at your line 56:

Code:

for(int i = 0; quizName.length > i; i++)
{
    String QuizNames = quizName[i];
    if(args.length > 1)
    {
       if(QuizNames.equalsIgnoreCase(args[1])) // <<< here
       {

It's because the QuizNames variable (which is badly named by the way, you should not use variables/fields/methods starting with upper case letter) is most likely null and you're using a method on it, and basically translates to "null.equalsIgnoreCase(...)" which just can't happen.

You should also learn about Lists, they have dynamic size unlike arrays which have fixed size.

 

Thanks for helping me find my error. Also thanks for giving me that tutorial link, it really helped!

 

DREAM_MACHINE I actually think its either the args[1] or the QuizNames.