Why this runtime error?

Code:

17:04:35 [INFO] Starting minecraft server version Beta 1.4
17:04:35 [INFO] Loading properties
17:04:35 [INFO] Starting Minecraft server on *:25565
17:04:35 [WARNING] **** SERVER IS RUNNING IN OFFLINE/INSECURE MODE!
17:04:35 [WARNING] The server will make no attempt to authenticate usernames. Be
ware.
17:04:35 [WARNING] While this makes the game possible to play without internet a
ccess, it also opens up the ability for hackers to connect with any username the
y choose.
17:04:35 [WARNING] To change this, set "online-mode" to "true" in the server.set
tings file.
17:04:35 [INFO] This server is running Craftbukkit version git-Bukkit-0.0.0-612-
g4c7a9e7-b617jnks (MC: 1.4)
17:04:35 [INFO] Preparing level "world"
17:04:35 [INFO] Preparing start region
17:04:35 [INFO] 144 recipes
17:04:36 [SEVERE] null loading NappoNameChange v0.1 (Is it up to date?)
java.lang.NullPointerException
        at com.nappo.bukkit.NameChangePlugin.onEnable(NameChangePlugin.java:15)
        at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:118)
        at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader
.java:514)
        at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManage
r.java:216)
        at org.bukkit.craftbukkit.CraftServer.loadPlugin(CraftServer.java:94)
        at org.bukkit.craftbukkit.CraftServer.loadPlugins(CraftServer.java:72)
        at net.minecraft.server.MinecraftServer.e(MinecraftServer.java:215)
        at net.minecraft.server.MinecraftServer.a(MinecraftServer.java:202)
        at net.minecraft.server.MinecraftServer.d(MinecraftServer.java:142)
        at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:257)
        at net.minecraft.server.ThreadServerApplication.run(SourceFile:375)
17:04:36 [INFO] Done (0.109s)! For help, type "help" or "?"
>

Here is the plugin code:

Code:

package com.nappo.bukkit;
import org.bukkit.plugin.java.JavaPlugin;

/**
 * Allows players to change their display names.
 * @author Canownueasy
 */
public class NameChangePlugin extends JavaPlugin {

	@Override
	public void onDisable() {}

	@Override
	public void onEnable() {
		getCommand("name").setExecutor(new NameChangeCommand());
	}

}

Code:

package com.nappo.bukkit;

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

/**
 * Executes the name change command.
 * @author Canownueasy
 */
public class NameChangeCommand implements CommandExecutor {

	@Override
	public boolean onCommand(CommandSender sender, Command command, String label, String[] args) {
		if(sender instanceof Player) {
			Player player = (Player) sender;
			if(player.isOnline()) {
				player.setDisplayName(args[0]);
				sender.sendMessage("Your display name has been set to: " + args[0]);
			}
			return true;
		}
		return false;
	}

}

 

Did you register the command in your plugin.yml?

 

No. How would I go about doing that?

 

I just started making plugins so not 100% sure but this seems to work (from looking at other plugins). I dont know where this is documented but if someone could point out where it is, I would be grateful.

In the plugin.yml you need to add a section for commands in this format

Code:

commands:
  [the_command]:
    description: [a_description_of_the_command]
    aliases: [any_alias]
    usage: /<command> [arguments]
  [the_command2]:
    description: [a_description_of_the_command2]
    aliases: [any_alias2]
    usage: /<command> [arguments2]

etc.

So for your case.

Code:

commands:
  name:
    description: Change your display name
    aliases: name      (Not sure if this line is necessary)
    usage: /<command> [new_name]

 

It's okay I just read the plugin loader but thanks anyway

 

Would you be so kind to point to where this info is? tia!

 

In the Bukkit source code.