NullPointerException error?

So I've run into a problem and have been trying to fix it all day.

When calling GMHook.getGroup(), I'm greeted with an internal error saying there's been a NullPointerException at net.zapkraft.zapkraftmc.GMHook.getGroup(GMHook.java:58) and at net.zapkraft.zapkraftmc.ZapkraftMC.blocklandAuthLookup(ZapkraftMC.java:95).

GMHook.java at problem region:

Code:

public String getGroup(final Player base)
{
final AnjoPermissionsHandler handler = groupManager.getWorldsHolder().getWorldPermissions(base);
if (handler == null)
{
return null;
}
return handler.getGroup(base.getName());
}

ZapkraftMC.java at problem region:

Code:

newHook = new GMHook(this);
           String groupString = newHook.getGroup(player);

The full error, if it helps somehow:

Code:

[19:23:30] [Server thread/ERROR]: null
org.bukkit.command.CommandException: Unhandled exception executing command 'vip' in plugin ZapkraftMC v0.1.0
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:46) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:175) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at org.bukkit.craftbukkit.v1_7_R1.CraftServer.dispatchCommand(CraftServer.java:683) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.PlayerConnection.handleCommand(PlayerConnection.java:952) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.PlayerConnection.a(PlayerConnection.java:814) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInChat.a(PacketPlayInChat.java:28) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.PacketPlayInChat.handle(PacketPlayInChat.java:47) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.NetworkManager.a(NetworkManager.java:146) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.u(MinecraftServer.java:655) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.DedicatedServer.u(DedicatedServer.java:250) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.t(MinecraftServer.java:545) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.MinecraftServer.run(MinecraftServer.java:457) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
at net.minecraft.server.v1_7_R1.ThreadServerApplication.run(SourceFile:617) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
Caused by: java.lang.NullPointerException
at net.zapkraft.zapkraftmc.GMHook.getGroup(GMHook.java:58) ~[?:?]
at net.zapkraft.zapkraftmc.ZapkraftMC.blocklandAuthLookup(ZapkraftMC.java:95) ~[?:?]
at net.zapkraft.zapkraftmc.ZapkraftMC.onCommand(ZapkraftMC.java:143) ~[?:?]
at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-b3020jnks]
... 13 more

 

Zapk
Is the groupManager field initialized?

 

Yes, if this is what you mean:

Code:

public final class ZapkraftMC extends JavaPlugin {
public GMHook newHook;

 

Zapk Zapk
No, the groupManager field from GMHook class

 

Oh. Yeah, I think so.

Code:

private GroupManager groupManager;

 

Zapk
No it isn't. Stop showing snippers and show full code. Its not obvious if you initialized it in the constructor either. Either way, learn how to assing your fields, this is basic stuff.

 

You're very helpful.

http://wiki.ess3.net/wiki/Group_Manager/Developers

 

He's being as helpful as he can...

It doesn't look like you're registering your events, so your variable is not being initialized.
Implement that class to Listener, and register it from your main class.

 

Zapk
Did you honestly just copy paste that...

 

Wolfey

How do I do that?

 

Looking at the class you posted, (http://wiki.ess3.net/wiki/Group_Manager/Developers), you need to implement it to Listener, and register it in your onEnable() method. (Bukkit.getPluginManager().registerEvents(new <ListenerClassName>, this);

 

Wolfey

Sorry, but how do I do this? getServer().getPluginManager().registerEvents(new GMHook(), this);?

 

Sorry for replying so late, but yes.