Solved IllegalArgumentException: Plugin cannot be null - I'm giving up

Code:

10:37:20 [SEVERE] Could not pass event PlayerInteractEvent to Modifications v0.1
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:427)
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62)
        at org.bukkit.plugin.TimedRegisteredListener.callEvent(TimedRegisteredListener.java:30)
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:478)
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:463)
        at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:207)
        at org.bukkit.craftbukkit.v1_6_R2.event.CraftEventFactory.callPlayerInteractEvent(CraftEventFactory.java:177)
        at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:608)
        at net.minecraft.server.v1_6_R2.Packet15Place.handle(SourceFile:58)
        at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:230)
        at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:116)
        at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
        at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:125)
        at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:592)
        at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
        at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
        at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
        at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)
Caused by: java.lang.IllegalArgumentException: Plugin cannot be null
        at org.apache.commons.lang.Validate.notNull(Validate.java:192)
        at org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftScheduler.validate(CraftScheduler.java:391)
        at org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftScheduler.runTaskTimer(CraftScheduler.java:120)
        at org.bukkit.craftbukkit.v1_6_R2.scheduler.CraftScheduler.runTaskLater(CraftScheduler.java:104)
        at org.rsod.Modifications.ItemBlastGrenade.onInteract(ItemBlastGrenade.java:127)
        at sun.reflect.GeneratedMethodAccessor860.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:425)
        ... 17 more

Code:java

Bukkit.getScheduler().runTaskLater((Modifications) Bukkit.getPluginManager().getPlugin("Modifications"), new ItemBlastGrenadeTask1(p), 10);

 

That is a bad way to do it.
pass an instance of the main class through the constructor of that class and save it in a variable called instance or something.

 

From what I see, that means is that

Code:

Bukkit.getPluginManager().getPlugin("Modifications")

Is null. There is no plugin called "Modifications". Check the name you used in your plugin.yml?

Edit: Do what tommycake said, it's much easier and will probably be less frustrating.

 

tommycake50 I originally used constructor, but it refused to work at all, even load plugin.

Code:

2013-08-15 10:13:25 [INFO] [Modifications] Enabling Modifications v0.1
2013-08-15 10:13:25 [SEVERE] Error occurred while enabling Modifications v0.1 (Is it up to date?)
java.lang.NoSuchMethodError: org.rsod.Modifications.ItemBlastGrenade.<init>(Lorg/rsod/Modifications/Modifications;)V
    at org.rsod.Modifications.Modifications.onEnable(Modifications.java:58)
    at org.bukkit.plugin.java.JavaPlugin.setEnabled(JavaPlugin.java:217)
    at org.bukkit.plugin.java.JavaPluginLoader.enablePlugin(JavaPluginLoader.java:457)
    at org.bukkit.plugin.SimplePluginManager.enablePlugin(SimplePluginManager.java:382)
    at net.diamondmine.reloader.PluginReloader.loadPlugin(PluginReloader.java:216)
    at net.diamondmine.reloader.PluginReloader.reloadPlugin(PluginReloader.java:252)
    at net.diamondmine.reloader.PluginReloader.onCommand(PluginReloader.java:89)
    at org.bukkit.command.PluginCommand.execute(PluginCommand.java:44)
    at org.bukkit.command.SimpleCommandMap.dispatch(SimpleCommandMap.java:192)
    at org.bukkit.craftbukkit.v1_6_R2.CraftServer.dispatchCommand(CraftServer.java:527)
    at net.minecraft.server.v1_6_R2.PlayerConnection.handleCommand(PlayerConnection.java:979)
    at net.minecraft.server.v1_6_R2.PlayerConnection.chat(PlayerConnection.java:890)
    at net.minecraft.server.v1_6_R2.PlayerConnection.a(PlayerConnection.java:837)
    at net.minecraft.server.v1_6_R2.Packet3Chat.handle(SourceFile:49)
    at org.spigotmc.netty.NettyNetworkManager.b(NettyNetworkManager.java:230)
    at net.minecraft.server.v1_6_R2.PlayerConnection.e(PlayerConnection.java:116)
    at net.minecraft.server.v1_6_R2.ServerConnection.b(SourceFile:37)
    at org.spigotmc.netty.NettyServerConnection.b(NettyServerConnection.java:125)
    at net.minecraft.server.v1_6_R2.MinecraftServer.t(MinecraftServer.java:592)
    at net.minecraft.server.v1_6_R2.DedicatedServer.t(DedicatedServer.java:239)
    at net.minecraft.server.v1_6_R2.MinecraftServer.s(MinecraftServer.java:481)
    at net.minecraft.server.v1_6_R2.MinecraftServer.run(MinecraftServer.java:413)
    at net.minecraft.server.v1_6_R2.ThreadServerApplication.run(SourceFile:582)

Axe2760
in another class in same package same method works just fine. As well as constructor way works fine with another classes. Only this won't work...

 

Can i see the constructor?

 

tommycake50

Code:java

public class ItemBlastGrenade implements Listener {
    private Modifications mplugin;
 
    public ItemBlastGrenade(Modifications plugin){
        this.mplugin = plugin;
    }
//...

onEnable method:

Code:java

@Override
    public void onEnable(){
        Bukkit.getPluginManager().registerEvents(new Listeners(), this);
        Bukkit.getPluginManager().registerEvents(new ExplosiveBow(this), this);
        Bukkit.getPluginManager().registerEvents(new TeleportationBow(this), this);
        Bukkit.getPluginManager().registerEvents(new ItemBlastGrenade(this), this);
        if(Bukkit.getPluginManager().getPlugin("NoCheatPlus") != null){
            Exempter.use = true;
        }
        this.getLogger().info("Enabled! test!");
    }

TeleportationBow and ExplosiveBow has THE SAME constructors and they are working correctly.

 

Also why are you using Bukkit and not getServer()?

 

tommycake50 hmm, would it change something? It doesn't changing anything anyways.

Code:java

@Override
public void onEnable(){
this.getServer().getPluginManager().registerEvents(new Listeners(), this);
this.getServer().getPluginManager().registerEvents(new ExplosiveBow(this), this);
this.getServer().getPluginManager().registerEvents(new TeleportationBow(this), this);
this.getServer().getPluginManager().registerEvents(new ItemBlastGrenade(this), this);
if(this.getServer().getPluginManager().getPlugin("NoCheatPlus") != null){
Exempter.use = true;
}
this.getLogger().info("Enabled! test!");
}

I have an idea what can I do, I'll try it and post if it will help or not.. but it will require more time.

 

rsod there's no practical difference between Bukkit.getPluginManager() and this.getServer().getPluginManager() - they get you the same PluginManager object. So not relevant.

Your stack trace shows a NoSuchMethod error for the ItemBlastGrenade constructor which takes a single argument of type Modifications. The code you posted looks OK (you do indeed have such a constructor), which leads me to believe that the ItemBlastGrenade.class file in your JAR is possibly out of date (i.e. there's a compiled version in your JAR which is lacking that constructor definition). Clean out your build environment and rebuild the plugin JAR from scratch and see if you still get the error.

 

Ok...
I deleted project from eclipse, then created it again, pasted all source codes...
and it works now...
wtf...

 

Yeah... stale class file in your JAR. Eclipse's build environment is somewhat ... sub-optimal. I switched to using Maven a long time ago, and haven't looked back

 

But if you import Bukkit you're wasting ram >:C

 

emm? How? It's kinda offtopic, but I'd like to know how.

 

Because when you import a class you're telling the JRE to load it into ram for your class to access it works almost like the preprocessor directives in C or C++.
Thats why its bad say if your using a JFrame to import javax.swing.* because you are loading the ENTIRE Swing library into ram.

 

I'm calling BS on this one.

Importing classes at compile-time has exactly zero effect on run-time RAM usage.

If you're concerned about the 10KB Bukkit.class file having an effect on compile-time memory usage, then seriously - get a computer that was built this century.

If you're concerned about the 10KB Bukkit.class file having an effect on run-time memory usage, I'll refer you to the previous comment, plus: it's almost certainly already loaded into the JVM already, since multiple Bukkit classes use it. If you have any plugin that uses permissions, the scheduler, or handles an ItemStack, then it's loaded. If you've used any builtin commands, then it's loaded.

Oh, and Java import works nothing like the C/C++ preprocessor.

 

right. good to know.

 

Axe2760
Assist
timtower
Sorry to bump this one up, but I am having the same problem, and this is not solving it. Here is my code:

Code:java

package me.HeyAwesomePeople.warframe;
 
import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.entity.Entity;
import org.bukkit.entity.Player;
import org.bukkit.util.Vector;
 
public abstract class Methods{
 
static Main plugin;
 
public Methods(Main instance) {
plugin = instance;
}
public static void mag1(Player player) {
if (player.getLevel() >= 25) {
/*
* TODO Pull the player on your cursor, bringing him into melee
* range!
*/
player.setLevel(player.getLevel() - 25);
} else {
player.sendMessage(ChatColor.RED
+ "You do not have enough XP levels to perform this ability!");
}
player.sendMessage(ChatColor.RED + "Mag's 1st power works!");
}
 
public static void mag2(Player player) {
if (player.getLevel() >= 100) {
for (final Entity entity : player.getNearbyEntities(6.0D, 6.0D, 6.0D)) {
if (entity instanceof Player) {
final Player nearby = (Player) entity;
nearby.setVelocity(new Vector(0, 4, 0));
Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
public void run(){
entity.getWorld().createExplosion(nearby.getLocation(), 1);
}
}, 20L); //replace the 3L to whatever delay you need
}
}
player.setLevel(player.getLevel() - 100);// Take 100 XP
} else {
player.sendMessage(ChatColor.RED
+ "You do not have enough XP levels to perform this ability!");
}
}
}
 

And my main class(Only part you would need):

Code:java

public class Main extends JavaPlugin {
public final Logger logger = Logger.getLogger("Minecraft");
public static Main plugin;
public final InteractListener1 bl = new InteractListener1(this);
// Lists
List<String> magUsers = new ArrayList<String>();
List<String> usedPlayCommand = new ArrayList<String>();
 
@Override
public void onEnable() {
PluginManager pm = getServer().getPluginManager();
pm.registerEvents(this.bl, this);
PluginDescriptionFile pdffile = this.getDescription();
this.logger.info(pdffile.getName() + " Has been enabled!");
 
getConfig().options().copyDefaults(false);
File file = new File("plugins" + File.separator + "MCWarframe"
+ File.separator + "config.yml");
if (!file.exists()) {
this.logger.info(pdffile.getName() + " - " + "INFO" + " - "
+ "Config file not found! Creating...");
FileConfiguration config = getConfig();
// Create default Lobby
config.set("Lobby." + "x", 0);
config.set("Lobby." + "y", 70);
config.set("Lobby." + "z", 0);
// Create default World
config.set("world", "world");
this.logger.info(pdffile.getName() + " - " + "INFO" + " - "
+ "Config file successfully created!");
}
saveConfig();
}
 
@Override
public void onDisable() {
PluginDescriptionFile pdffile = this.getDescription();
this.logger.info(pdffile.getName() + " Has been disabled!");
}

Whenever I try to perform mag2() it throws a plugin cannot be null error on

Code:java

 Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable()

 

HeyAwesomePeople How are you calling it? For example,

Code:

public class Main extends JavaPlugin{
  //creating an instance of your methods class
  public Methods m;
  @Override
  public void onEnable(){
    //passes a valid instance of your plugin to the constructor
    m = new Methods(this);
    //run mag2
    m.mag2(\*player*\);
  }
}

Apply that to your main class.

 

Axe2760
The mag2() method is being designed to throw a player in the air, then make them explode while in the air. So its being called actually on right click event with a stick.

 

HeyAwesomePeople Sorry, I mean how are you calling the methods class?

 

Axe2760
Calling it? All I use to get mag2 is:

Code:java

Methods.mag2(player);

Nothing else.

 

HeyAwesomePeople Thats your problem. Without the constructor, plugin is still null. Inside the constructor your setting your plugin variable to instance. Well, take that bit off, and the only thing that defines plugin is

Code:

public Main plugin;

Which isn't instantiated, and returns null until you assign it something.

By doing Methods.mag2, you're leaving out the constructor. Instead, make an instance of your class methods.

Code:

Methods methods = new Methods(this);

If you're calling it from another class, repeat the process, per se.

Code:

public class MyListener implements Listener{
  private Main plugin;
  private Methods methods;
  public MyListener(Main plugin){
    this.plugin = plugin;
    this.methods = new Methods(plugin);
  }
  @EventHandler
  public void blabla(blabla){
    methods.mag2(event.getPlayer());
  }
}

Code:

public class DerpPlugin extends JavaPlugin{
  @Override
  public void onEnable(){
    this.getServer().getPluginManager().registerEvents(new MyListener(this), this); //notice the constructor
  }
}

 

I think (I could be wrong about this), but, You have mag2 as static, and because of this it's possible that plugin is not set. try making mag2 non-static, and using an object of the class when using mag2

Edit: Ninja'd

 

Axe2760
I was told this was simple.

Where do I place that?

So this in my InteractListener1? Now this:
this.methods = new Methods(plugin);
Error: Cannot instantiate the type Methods
And private Methods methods is unused.

I already do this in my Main class. Look at the code.

 

HeyAwesomePeople Derp, I didn't realize your class was abstract/you can't instantitiate it. I'd honestly just make it not abstract, not sure. As for doing it in the main class, I was referring to passing an instance of the plugin to both classes, not registering events.

 

Axe2760
Okay. I forgot it was abstract. Removed. Everything else imported as you said.
EDIT: OH MY GOSH. THANK YOU. I HAVE BEEN WORKING ON THIS FOR HOURS!
THANK YOU.

 

HeyAwesomePeople Haha, no problem. Good luck!