Creating a few runnables in one method.

Okay, that title probably wasn't descriptive enough.

What I'm trying to do, is make it so when the player clicks an enderpearl in a seperate inventory (cmRecipesMighty) it loads or "sets" the item slots in that inventory to the item, using this

Code:

                        cmRecipesMighty.setItem(22, new ItemStack(Material.BLAZE_POWDER, 1));

but what I'm trying to do, is make it so when the player clicks that enderpearl, it loads the Blaze Powder, then 1 second later it loads the Iron Ingots, then 1 second after that it loads the Gold Ingots.

Putting 3 runnables inside of the method didn't work
I then tried putting 3 "if" checks, that didn't work.

Code:

            }
            if (clicked.getType() == Material.ENDER_PEARL) {
                event.setCancelled(true);
                Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
                    public void run() {
                        player.sendMessage(ChatColor.AQUA + "Loading the recipe for the '" + ChatColor.BLUE + "Mighty" + ChatColor.AQUA + "' item!");
                        cmRecipesMighty.setItem(22, new ItemStack(Material.BLAZE_POWDER, 1));
                    }
                }, 20L);
                Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
                    public void run() {
                        cmRecipesMighty.setItem(13, new ItemStack(Material.IRON_INGOT, 1));
                        cmRecipesMighty.setItem(31, new ItemStack(Material.IRON_INGOT, 1));
                    }
                }, 2 * 20L);
                Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
                    public void run() {
                        cmRecipesMighty.setItem(21, new ItemStack(Material.GOLD_INGOT, 1));
                        cmRecipesMighty.setItem(23, new ItemStack(Material.GOLD_INGOT, 1));
                        player.sendMessage(ChatColor.AQUA + "Recipe has loaded!");
                    }
                }, 3 * 20L);
                return;

If you look there you might be able to see what I'm trying to do exactly,
Loading 1 item after another with a delay of 1 second inbetween.

The error it's throwing in console:

Code:

[23:02:21 ERROR]: Could not pass event InventoryClickEvent to CM v0.1.001
org.bukkit.event.EventException
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:310) ~[spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.jav
a:62) ~[spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.j
ava:502) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.j
ava:487) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java
:1630) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31)
[spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9)
[spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:1
3) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [
?:1.8.0_72]
        at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_72]
        at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [spigot188.
jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:7
14) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:3
74) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:6
53) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java
:556) [spigot188.jar:git-Spigot-fdc1440-53fac9f]
        at java.lang.Thread.run(Unknown Source) [?:1.8.0_72]
Caused by: java.lang.NullPointerException
        at me.themaniacgamers.CM.Main.listeners.RecipesListener.oncmRecipesMight
yClick(RecipesListener.java:232) ~[?:?]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0
_72]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0
_72]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1
.8.0_72]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_72]
        at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.ja
va:306) ~[spigot188.jar:git-Spigot-fdc1440-53fac9f]
        ... 15 more
>

Thanks for your help!

 

https://bukkit.org/threads/how-to-r...ubleshoot-your-own-plugins-by-yourself.32457/
Please read this, look over your error, and try to figure out which line is causing the problem.

 

@TheManiacGamers Either the held item is null, or cmRecipesMighty is null. Not sure how you could look at an NPE and conclude that you couldn't call the scheduler 3 times in a row.
For future reference, you should always post your entire class, and also the main class if it's separate. Don't just post code you perceive to be relevant, because the problem is often that you don't perceive the other code to be relevant.
Also, tip: This is what you're doing.

Code:

Bukkit.getServer().getScheduler().scheduleSyncDelayedTask(plugin, new Runnable() {
    public void run() {
        //...
    }
}, 20L);

This is the easier and more supported way:

Code:

new BukkitRunnable() {
    public void run() {
        //...
    }
}.runTaskLater(plugin, 20L);

 

Thanks! Got it working.