Solved BukkitRunnable task error Plugin already initialized

Error:

Code:

[22:11:43 ERROR]: Could not pass event JoinStageEvent to MurderCraft v0.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at com.kjSmitten.listener.GameSelectInventoryListener.onJoinGame(GameSelectInventoryListener.java:24) [MurderCraft.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:1361) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.a(SourceFile:32) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.handle(SourceFile:10) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:148) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
Caused by: java.lang.IllegalArgumentException: Plugin already initialized!
    at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:98) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:59) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at com.kjSmitten.murdercraft.MurderCraft.<init>(MurderCraft.java:24) ~[?:?]
    at com.kjSmitten.listener.StageListener.onStageJoinEvent(StageListener.java:51) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    ... 22 more
Caused by: java.lang.IllegalStateException: Initial initialization
    at org.bukkit.plugin.java.PluginClassLoader.initialize(PluginClassLoader.java:101) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.java.JavaPlugin.<init>(JavaPlugin.java:59) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at com.kjSmitten.murdercraft.MurderCraft.<init>(MurderCraft.java:24) ~[?:?]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) ~[?:1.6.0_65]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513) ~[?:1.6.0_65]
    at java.lang.Class.newInstance0(Class.java:357) ~[?:1.6.0_65]
    at java.lang.Class.newInstance(Class.java:310) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.PluginClassLoader.<init>(PluginClassLoader.java:52) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.java.JavaPluginLoader.loadPlugin(JavaPluginLoader.java:127) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.loadPlugin(SimplePluginManager.java:328) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:251) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.craftbukkit.v1_7_R3.CraftServer.loadPlugins(CraftServer.java:350) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.craftbukkit.v1_7_R3.CraftServer.<init>(CraftServer.java:312) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PlayerList.<init>(PlayerList.java:68) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.DedicatedPlayerList.<init>(SourceFile:14) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.init(DedicatedServer.java:126) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:436) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    ... 1 more

Task Class:

Code:java

public class StartGameTask extends BukkitRunnable{
 
    private final Stage stage;
    private int counter = 45;
 
    public StartGameTask(Plugin plugin, Stage stage){
        this.stage = stage;
        stage.setGameState(GameState.PRE_GAME);
        runTaskTimer(plugin, 0, 20);
    }
 
    public void run() {
        if(stage.getGameState() == GameState.IDLE || stage.getGameState() == GameState.IN_GAME){
            cancel();
        }
 
        if(stage.getWaitingPlayerList().size() < 2){
            try {
                for(Player player : stage.getWaitingPlayerList()){
                    player.sendMessage(ChatColor.RED + "Too few players! Game cancelled!");
                }
            } catch (Exception e) {}
            cancel();
        }
 
        switch(counter){
        case 45:
            for(Player player : stage.getWaitingPlayerList()){
                player.sendMessage("" + ChatColor.BOLD + ChatColor.YELLOW + counter + " seconds until match starts!");
            }
        case 30:
            for(Player player : stage.getWaitingPlayerList()){
                player.sendMessage("" + ChatColor.BOLD + ChatColor.YELLOW + counter + " seconds until match starts!");
            }
        case 20:
            for(Player player : stage.getWaitingPlayerList()){
                player.sendMessage("" + ChatColor.BOLD + ChatColor.YELLOW + counter + " seconds until match starts!");
            }
        }
 
        if(counter >= 10 && counter > 0){
            for(Player player : stage.getWaitingPlayerList()){
                player.sendMessage("" + ChatColor.BOLD + ChatColor.YELLOW + counter + " seconds until match starts!");
            }
        }
 
        if(counter == 0){
            stage.setGameState(GameState.IN_GAME);
            stage.getTeamHandler().assortPlayersToTeams(stage.getWaitingPlayerList());
            stage.getTeamHandler().getMurderer().sendMessage(ChatColor.YELLOW + "You are a " + ChatColor.BOLD + ChatColor.RED + "MURDERER");
            for(Player player : stage.getTeamHandler().getBystanderTeam().getPlayers()){
                if(player.getInventory().contains(Material.BOW)){
                    player.sendMessage(ChatColor.YELLOW + "You are a " + ChatColor.BOLD + ChatColor.DARK_PURPLE + "BYSTANDER" + ChatColor.RESET + ChatColor.YELLOW + " with a " + ChatColor.DARK_PURPLE + "SECRET WEAPON");
                }else{
                    player.sendMessage(ChatColor.YELLOW + "You are a " + ChatColor.BOLD + ChatColor.BLUE + "BYSTANDER");
                }
            }
 
            stage.addPlayers(stage.getWaitingPlayerList());
            stage.getWaitingPlayerList().clear();
 
            for(Player player : stage.getPlayers()){
                player.addPotionEffect(new PotionEffect(PotionEffectType.BLINDNESS, 20 * 5, 0, true), true);
            }
        }
 
        counter--;
    }
 
}

Class that uses task:

Code:java

public class StageListener implements Listener{
 
    @EventHandler
    private void onStageJoin(JoinStageEvent event){
        Stage stage = event.getStage();
        GameState state = event.getStage().getGameState();
 
        if(!stage.isJoinable()){
            event.setCancelled(true);
        }
 
        event.getPlayer().getInventory().clear();
        MainLobby.getPlayers().remove(event.getPlayer());
 
        if(state == GameState.IDLE || state == GameState.PRE_GAME){
            stage.addWaitingPlayer(event.getPlayer());
            for(Player player : event.getStage().getPlayers()){
                player.sendMessage(ChatColor.YELLOW + "[" + ChatColor.RED + "Murder" + ChatColor.BLUE + "Craft" + ChatColor.YELLOW + "] <Join> " + ChatColor.AQUA + ChatColor.BOLD + event.getPlayer().getName() +
                        ChatColor.RESET + ChatColor.YELLOW + " has joined!");
            }
 
            if(stage.getWaitingPlayerList().size() >= 2){
                new StartGameTask(new MurderCraft(), stage);
                //MurderCraft is the main class.
            }
        }else if(state == GameState.IN_GAME){
            stage.addSpectator(event.getPlayer());
        }
    }
}

I really am clueless as to why this is causing an error. Please help me.

 

new StartGameTask(new MurderCraft(), stage);

why nobody read javadocs?

 

You need to use your current plugin instance, you can't create new one.

Code:

//you can't do new MurderCraft()
new StartGameTask(new MurderCraft(), stage);

Edit:
RawCode
I don't think this is about reading docs.

 

I changed it to this:

Code:java

    private MurderCraft plugin;
 
    @EventHandler
    private void onStageJoin(JoinStageEvent event){
        Stage stage = event.getStage();
        GameState state = event.getStage().getGameState();
 
        if(!stage.isJoinable()){
            event.setCancelled(true);
        }
 
        event.getPlayer().getInventory().clear();
        MainLobby.getPlayers().remove(event.getPlayer());
 
        if(state == GameState.IDLE || state == GameState.PRE_GAME){
            stage.addWaitingPlayer(event.getPlayer());
            for(Player player : event.getStage().getPlayers()){
                player.sendMessage(ChatColor.YELLOW + "[" + ChatColor.RED + "Murder" + ChatColor.BLUE + "Craft" + ChatColor.YELLOW + "] <Join> " + ChatColor.AQUA + ChatColor.BOLD + event.getPlayer().getName() +
                        ChatColor.RESET + ChatColor.YELLOW + " has joined!");
            }
 
            if(stage.getWaitingPlayerList().size() >= 2 && state == GameState.IDLE){
                new StartGameTask(plugin, stage);
            }
        }else if(state == GameState.IN_GAME){
            stage.addSpectator(event.getPlayer());
        }
    }

Haven't tested it yet. Crossed fingers.

 

raGan. JavaDoc for exceptions generally tell you why the exception may have been thrown. Some methods also document under what conditions the method will throw an exception/

You should change it to a reference to your plugin's main class. If you don't understand what that is, I suggest you read this chapter http://math.hws.edu/eck/cs124/javanotes6/c5/index.html

 

I added this to the main class:

Code:java

public MurderCraft getInstance(){
        return this;
    }

And used it in the listener class:

Code:java

private MurderCraft plugin;
 
    @EventHandler
    private void onStageJoin(JoinStageEvent event){
        Stage stage = event.getStage();
        GameState state = event.getStage().getGameState();
 
        if(!stage.isJoinable()){
            event.setCancelled(true);
        }
 
        event.getPlayer().getInventory().clear();
        MainLobby.getPlayers().remove(event.getPlayer());
 
        if(state == GameState.IDLE || state == GameState.PRE_GAME){
            stage.addWaitingPlayer(event.getPlayer());
            for(Player player : event.getStage().getPlayers()){
                player.sendMessage(ChatColor.YELLOW + "[" + ChatColor.RED + "Murder" + ChatColor.BLUE + "Craft" + ChatColor.YELLOW + "] <Join> " + ChatColor.AQUA + ChatColor.BOLD + event.getPlayer().getName() +
                        ChatColor.RESET + ChatColor.YELLOW + " has joined!");
            }
 
            if(stage.getWaitingPlayerList().size() >= 2 && state == GameState.IDLE){
                new StartGameTask(plugin.getInstance(), stage);
            }
        }else if(state == GameState.IN_GAME){
            stage.addSpectator(event.getPlayer());
        }
    }

But now I get a null pointer exception:

Code:

[22:51:58 ERROR]: Could not pass event JoinStageEvent to MurderCraft v0.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at com.kjSmitten.listener.GameSelectInventoryListener.onJoinGame(GameSelectInventoryListener.java:24) [MurderCraft.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:1361) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.a(SourceFile:32) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.handle(SourceFile:10) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:148) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
Caused by: java.lang.NullPointerException
    at com.kjSmitten.listener.StageListener.onStageJoin(StageListener.java:54) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    ... 22 more

 

I know, I wasn't talking about docs not being helpful in this situation, I was just rude. (I lost it for a second.)

 

kjSmitten What is on line 54 of StageListener.java?

 

coasterman10

Code:java

new StartGameTask(plugin.getInstance(), stage);

 

kjSmitten I was guessing this would be the troublesome line. What do you have in your main class pertaining to getInstance()?

 

Perhaps initialize a public static variable in the MurderCraft main class and then return that variable in getInstance()? Try not accessing the plugin in a non-static way. If need be, do MurderCraft.plugin as the instance.

Code:

new StartGameTask(MurderCraft.plugin, stage);
or
new StartGameTask(MurderCraft.getInstance(), stage);
 
///////////////////////////////// MurderCraft setup
public static MurderCraft plugin;
 
public static Plugin getInstance() {
    return plugin;
}

 

coasterman10

Code:java

public MurderCraft getInstance(){
        return this;
}

 

I thought getInstance() methods were static, are they not?

 

That method is redundant, it is effectively no different than just typing "plugin" since "plugin.getInstance()" will just return the same thing as "plugin".

Are you actually setting the "plugin" variable?

getInstance() should be a static method if it is meant to be used as a singleton. It's still a better idea to use dependency injection here though.

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

 

Drkmaster83

Code:

[23:26:55 ERROR]: Could not pass event JoinStageEvent to MurderCraft v0.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:294) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at com.kjSmitten.listener.GameSelectInventoryListener.onJoinGame(GameSelectInventoryListener.java:24) [MurderCraft.jar:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:501) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:486) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PlayerConnection.a(PlayerConnection.java:1361) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.a(SourceFile:32) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.PacketPlayInWindowClick.handle(SourceFile:10) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.NetworkManager.a(NetworkManager.java:148) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ServerConnection.c(SourceFile:134) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.v(MinecraftServer.java:667) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.DedicatedServer.v(DedicatedServer.java:260) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.u(MinecraftServer.java:558) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.MinecraftServer.run(MinecraftServer.java:469) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    at net.minecraft.server.v1_7_R3.ThreadServerApplication.run(SourceFile:628) [craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
Caused by: java.lang.NullPointerException
    at com.kjSmitten.listener.StageListener.onStageJoin(StageListener.java:54) ~[?:?]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.6.0_65]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[?:1.6.0_65]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[?:1.6.0_65]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[?:1.6.0_65]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:292) ~[craftbukkit.jar:git-Bukkit-1.7.2-R0.3-21-g1ab090e-b3050jnks]
    ... 22 more

 

With what code?

 

Drkmaster83

Code:java

 private MurderCraft plugin;
 
@EventHandler
private void onStageJoin(JoinStageEvent event){
Stage stage = event.getStage();
GameState state = event.getStage().getGameState();
 
if(!stage.isJoinable()){
event.setCancelled(true);
}
 
event.getPlayer().getInventory().clear();
MainLobby.getPlayers().remove(event.getPlayer());
 
if(state == GameState.IDLE || state == GameState.PRE_GAME){
stage.addWaitingPlayer(event.getPlayer());
for(Player player : event.getStage().getPlayers()){
player.sendMessage(ChatColor.YELLOW + "[" + ChatColor.RED + "Murder" + ChatColor.BLUE + "Craft" + ChatColor.YELLOW + "] <Join> " + ChatColor.AQUA + ChatColor.BOLD + event.getPlayer().getName() +
ChatColor.RESET + ChatColor.YELLOW + " has joined!");
}
 
if(stage.getWaitingPlayerList().size() >= 2 && state == GameState.IDLE){
new StartGameTask(plugin.getInstance(), stage);
}
}else if(state == GameState.IN_GAME){
stage.addSpectator(event.getPlayer());
}
}

Also tried creating a MurderCraft instance in the main class but that gives the same error

 

coasterman10 kjSmitten He is not initializing his 'plugin' variable, which is the problem. You could try what coasterman has recommended and pass in an instance of your main class through the class that requires it's constructor.

 

kjSmitten
Sagacious_Zed was actually the most helpful person here. May I recommend rereading his post?

 

xTigerRebornx If you mean in the listener class do:

Code:java

private MurderCraft plugin = new MurderCraft();

that doesn't work.

raGan. I tried what he suggested. Just returns a null pointer exception.
Main class:

Code:java

public MurderCraft INSTANCE = this;

Listener class:

Code:java

private MurderCraft plugin;
 
    @EventHandler
    private void onStageJoin(JoinStageEvent event){
        Stage stage = event.getStage();
        GameState state = event.getStage().getGameState();
 
        if(!stage.isJoinable()){
            event.setCancelled(true);
        }
 
        event.getPlayer().getInventory().clear();
        MainLobby.getPlayers().remove(event.getPlayer());
 
        if(state == GameState.IDLE || state == GameState.PRE_GAME){
            stage.addWaitingPlayer(event.getPlayer());
            for(Player player : event.getStage().getPlayers()){
                player.sendMessage(ChatColor.YELLOW + "[" + ChatColor.RED + "Murder" + ChatColor.BLUE + "Craft" + ChatColor.YELLOW + "] <Join> " + ChatColor.AQUA + ChatColor.BOLD + event.getPlayer().getName() +
                        ChatColor.RESET + ChatColor.YELLOW + " has joined!");
            }
 
            if(stage.getWaitingPlayerList().size() >= 2 && state == GameState.IDLE){
                new StartGameTask(plugin.INSTANCE, stage);
            }
        }else if(state == GameState.IN_GAME){
            stage.addSpectator(event.getPlayer());
        }
    }

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

 

kjSmitten No, if you don't understand what coasterman10 meant by dependency injection, try googling it. Also, read over the link that Sagacious_Zed posted, it should help you actually understand what he recommended.

 

Remember that stack trace you opened the thread with? You are encountering the same problem which you first seek out to fix. you cannot instantiate a new instance of your plugin, you have to refer to the single instance Bukkit creates.

 

kjSmitten No, what you should do is pass in the existing instance of your main class to the listener through its constructor. This is known as dependency injection and it's a very important concept that you will probably be using extensively as you get to more complicated plugins.

In your listener class, you define a final instance variable of your main class. In the constructor, you accept an instance of your main class as an argument, and then put that in the instance variable, like so:

Code:java

private final MurderCraft plugin;
 
public StageListener(MurderCraft plugin) {
  this.plugin = plugin;
}

Now, you will have an instance of the main class passed in that you can freely use throughout your listener class. In your main class, when you initialize your listener class, you have it pass itself to the listener class's constructor:

Code:java

new StageListener(this);

 

Sagacious_Zed Well way to go Captain Obvious. I figured that out a wile ago. And even when I make a that returns the main class instance it just throws a null pointer exception. (Sorry for rude sarcasm. I'm tired and have been trying to figure this thing out for at least a week before posting here.)

 

kjSmitten The main class instance would have worked if you made it static. It was not static, so it was still tied to instances of your main class, thus getting you nowhere. That is the singleton pattern and generally is considered a cop-out in most scenarios where dependency injection would be easier. Singletons are useful in some applications, but it's not good to get used to using static to access everything; it may seem easier at first, but it quickly makes a mess as your code gets more complex.

 

https://github.com/RawCode/UBT/blob/master/src/rc/ubt/Loader.java

lines from 41 to 44

https://github.com/RawCode/UBT/blob/master/src/rc/ubt/hnde/ForcedRespawn.java

line 18

This is *best* way of referencing singletron main plugin.
Due nature of <init> section this will work without any issues with reloads and hotplug.

 

A NullPointerException is a different problem. It is mostly thrown when you try to use null in an operation that cannot happen, such as calling a method on a null pointer. If your code causes a NullPointerException, you need to fix it so it returns a real object.

Edit: for more reference, https://github.com/SagaciousZed/SampleBukkitPlugin there is a listener that takes an instance of the main class, and how that main class arranges for the listener to receive that reference.

 

coasterman10 THANK YOU. It finally worked!