Reloading my plugin

So I got this code (Parts of it did I get from another plugin) and it gives me an error, but everything seems fine to me =/
(Error: http://pastebin.com/LGUc0RcG)

Code:java

package me.Matti.Sjabloon;
 
import java.io.File;
import java.util.Map;
import java.io.IOException;
import java.lang.reflect.Field;
import java.net.URLClassLoader;
import java.util.Iterator;
import java.util.List;
 
import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.PluginCommand;
import org.bukkit.command.SimpleCommandMap;
import org.bukkit.event.Listener;
import org.bukkit.plugin.InvalidDescriptionException;
import org.bukkit.plugin.InvalidPluginException;
import org.bukkit.plugin.Plugin;
import org.bukkit.plugin.SimplePluginManager;
import org.bukkit.plugin.UnknownDependencyException;
import org.bukkit.plugin.java.JavaPlugin;
import org.bukkit.plugin.java.JavaPluginLoader;
import org.bukkit.ChatColor;
import org.bukkit.command.CommandSender;
 
 
 
public class Reloader extends JavaPlugin implements Listener {
      private SimpleCommandMap scm;
      private Map<String, Command> kc;
      private Field loadersF;
    public void onEnable() {
        getServer().getPluginManager().registerEvents(this, this);
 
    }
      public Plugin loadPlugin(String name)
      {
        try
        {
          return Bukkit.getServer().getPluginManager().loadPlugin(new File("plugins" + File.separator + name + ".jar"));
        }
        catch (InvalidPluginException|InvalidDescriptionException|UnknownDependencyException e)
        {
          e.printStackTrace();
        }
        return null;
      }
 
 
 
 
 
 
 
 
 
 
 
        @SuppressWarnings("unchecked")
        public boolean unloadPlugin(Plugin plugin)
          {
            try
            {
              plugin.getClass().getClassLoader().getResources("*");
            }
            catch (IOException e1)
            {
              e1.printStackTrace();
            }
            SimplePluginManager spm = (SimplePluginManager)Bukkit.getServer().getPluginManager();
            Map<String, Plugin> ln;
            List<Plugin> pl;
            try
            {
              Field lnF = spm.getClass().getDeclaredField("lookupNames");
              lnF.setAccessible(true);
              ln = (Map)lnF.get(spm);
 
 
              Field plF = spm.getClass().getDeclaredField("plugins");
              plF.setAccessible(true);
              pl = (List)plF.get(spm);
            }
            catch (Exception e)
            {
              e.printStackTrace();
              return false;
            }
            synchronized (this.scm)
            {
              Iterator<Map.Entry<String, Command>> it = this.kc.entrySet().iterator();
              while (it.hasNext())
              {
                Map.Entry<String, Command> entry = (Map.Entry)it.next();
                if ((entry.getValue() instanceof PluginCommand))
                {
                  PluginCommand c = (PluginCommand)entry.getValue();
                  if (c.getPlugin().getName().equalsIgnoreCase(plugin.getName()))
                  {
                    c.unregister(this.scm);
                    it.remove();
                  }
                }
              }
            }
            spm.disablePlugin(plugin);
            synchronized (spm)
            {
              ln.remove(plugin.getName());
              pl.remove(plugin);
            }
            JavaPluginLoader jpl = (JavaPluginLoader)plugin.getPluginLoader();
            if (this.loadersF == null) {
              try
              {
                this.loadersF = jpl.getClass().getDeclaredField("loaders");
                this.loadersF.setAccessible(true);
              }
              catch (Exception e)
              {
                e.printStackTrace();
              }
            }
            try
            {
              Map<String, ?> loaderMap = (Map)this.loadersF.get(jpl);
 
              loaderMap.remove(plugin.getDescription().getName());
            }
            catch (Exception e)
            {
              e.printStackTrace();
            }
            closeClassLoader(plugin);
            System.gc();
            System.gc();
 
            return true;
          }
        public boolean closeClassLoader(Plugin plugin)
          {
            try
            {
              ((URLClassLoader)plugin.getClass().getClassLoader()).close();
              return true;
            }
            catch (IOException e)
            {
              e.printStackTrace();
            }
            return false;
          }
        public File getFile(JavaPlugin p)
          {
            try
            {
              Field f = JavaPlugin.class.getDeclaredField("file");
              f.setAccessible(true);
              return (File)f.get(p);
            }
            catch (Exception e)
            {
              e.printStackTrace();
            }
            return null;
          }
    @Override
    public boolean onCommand(CommandSender sender, Command command,
            String label, String[] args) {
        if(label.equalsIgnoreCase("MattiReload")){
            String pName = "Pixelmon";
            Plugin plugin = Bukkit.getServer().getPluginManager().getPlugin(pName);
            if (plugin == null)
            {
              sender.sendMessage(ChatColor.RED + "No such plugin: " + pName);
            }
            else
            {
              File file = getFile((JavaPlugin)plugin);
              JavaPlugin loaded = null;
              if (file == null)
              {
                sender.sendMessage(ChatColor.RED + plugin.getName() + "'s jar file is missing!");
                return true;
              }
              String fname = file.getName().substring(0, file.getName().length() - 4);
 
 
              if (!unloadPlugin(plugin)) {
                sender.sendMessage(ChatColor.RED + "An error occurred while unloading " + pName + "!");
              } else if ((loaded = (JavaPlugin)loadPlugin(fname)) == null) {
                sender.sendMessage(ChatColor.RED + "Failed to load " + fname + "!" + (sender != Bukkit.getConsoleSender() ? "Check console for details!" : ""));
              }
              Bukkit.getServer().getPluginManager().enablePlugin(loaded);
              sender.sendMessage(ChatColor.GREEN + loaded.getDescription().getName() + " reloaded successfully.");
 
            }
            return true;
          }
 
        return false;
    }
}

 

mattibijnens Something tells me that you're not ready to be doing this sort of thing.

 

AdamQpzm That's not really helping ...

 

mattibijnens Well it's honest. Tell us what you want to do exactly, and maybe we can help more.

 

AdamQpzm I would like to reload my plugin, but because you can't reload a plugin itself, I made another one for that. I coded this and I don't understand why it is giving this error.

 

What parts of it need to be reloaded, though? Because, chances are, you really don't need to do this, especially if you can't understand the error you're getting.

 

mattibijnens Something is null on the line

Code:java

Iterator<Map.Entry<String, Command>> it = this.kc.entrySet().iterator();

I can see what. Can you?

 

AdamQpzm I am reloading it beacuse I am constantly updating it

theguynextdoor I don't, unless you didn't see

Code:java

      private Map<String, Command> kc;

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

 

mattibijnens That's exactly what I saw. If you know java, you know your mistake.

 

theguynextdoor Looks like I don't then ...

 

mattibijnens Didn't read the code because AdamQpzm is totally right, but what theguynextdoor means is that kc is null, you have to do: private Map<String, Command> kc = new HashMap<String, Command>();

 

mattibijnens You're never assigning kc to anything, therefor it's null.

 

mattibijnens That's the problem with copying code - you miss parts, which can easily cause problems. Again, what parts are you reloading? Because config can be reloaded with a simple method call, plugin variables can be changed/reset, tasks can be cancelled... Off the top of my head, I've no idea why you would need to physically unload and then load the plugin, insomuch that not even enablePlugin() and disablePlugin() would work.

 

If you want to do a full reload of just your plugin, just execute the same code that you use in your onEnable() method. I don't know if calling the onEnable() method again would cause errors not related to your code but I would assume not.

 

As I already said before, I am making this because I am constantly updating the plugin, but I don't want to reload the whole server each time.
And Thanks werter318 =)