Transferring a player's inventory to a GUI

I am trying to create a trash disposal inventory, and I am attempting to add an option where, when a player clicks a nether star, their inventory is transported to the gui.

However, when I click the nether star I get a ton of errors on the console.

Here is the code:


if (event.getSlot() == 53) {
event.setCancelled(true);

ItemStack[] inv = player.getInventory().getContents();
Inventory inventory = event.getInventory();

inventory.addItem(inv);
player.getInventory().clear();
return;
}


I've tried using "inventory.setContents(inv)" but it's not the method that I want to use, as it removes the nether star.

Does anyone have any idea how to fix this?

 

Try looping through their inventory, and clearing each item individually if it isn't that nether star.

 

@UnpeeledBanana1
Error logs are much appreciated, and please use code tags next time.

 

@megamichiel Sorry about that, i'm sorta new to Bukkit forums, here's the error log:

Code:

[19:45:00] [Server thread/ERROR]: Could not pass event InventoryClickEvent to BananaESSENTIALS v1.0
org.bukkit.event.EventException
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:310) ~[paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at org.bukkit.plugin.RegisteredListener.callEvent(RegisteredListener.java:62) ~[paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at org.bukkit.plugin.SimplePluginManager.fireEvent(SimplePluginManager.java:502) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at org.bukkit.plugin.SimplePluginManager.callEvent(SimplePluginManager.java:487) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.PlayerConnection.a(PlayerConnection.java:1633) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:31) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.PacketPlayInWindowClick.a(SourceFile:9) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.PlayerConnectionUtils$1.run(SourceFile:13) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:1.8.0_31]
    at java.util.concurrent.FutureTask.run(Unknown Source) [?:1.8.0_31]
    at net.minecraft.server.v1_8_R3.SystemUtils.a(SourceFile:44) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.MinecraftServer.B(MinecraftServer.java:771) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.DedicatedServer.B(DedicatedServer.java:378) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.MinecraftServer.A(MinecraftServer.java:710) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at net.minecraft.server.v1_8_R3.MinecraftServer.run(MinecraftServer.java:613) [paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at java.lang.Thread.run(Unknown Source) [?:1.8.0_31]
Caused by: java.lang.IllegalArgumentException: Item cannot be null
    at org.apache.commons.lang.Validate.noNullElements(Validate.java:364) ~[paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at org.bukkit.craftbukkit.v1_8_R3.inventory.CraftInventory.addItem(CraftInventory.java:265) ~[paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    at me.UnpeeledBanana1.bananaessentials.commands.gui.inventoryclick.trashI.onInventoryClick(trashI.java:37) ~[?:?]
    at sun.reflect.GeneratedMethodAccessor80.invoke(Unknown Source) ~[?:?]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:1.8.0_31]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[?:1.8.0_31]
    at org.bukkit.plugin.java.JavaPluginLoader$1.execute(JavaPluginLoader.java:306) ~[paperspigot-1.8.8.jar:git-PaperSpigot-6d0a86a-53fac9f]
    ... 15 more

 

It's because you are trying to add an item to the inventory, even if there is nothing in that slot.

Edit: I think a for loop would serve your better:

Code:

for (ItemStack item : player.getInventory().getContents) {
    if (item == null) return;
    event.getInventory.addItem(item);
    player.getInventory().clear();
}

Also, there is no reason to declare a variable if you only use it once.

Edit2: @megamichiel I ninja'd you

 

@UnpeeledBanana1
Ah, I found your issue.
Inventory#getContents() returns an array of all the items within the inventory in their corresponding slot, but this includes empty slots, so it throws a NullPointerException because the slot is empty and therefor the item in the slot is null. You need to manually iterate over the Inventory#getContents() And check if the item is not null, and then add it.

 

Code:

public static Inventory viewInv(Player p) {    
Inventory inv = Bukkit.createInventory(Player#, InventoryType.PLAYER);
        inv.setContents(p.getInventory().getContents());
        return inv;
}

then to open the inventory do:

Code:

Player#openInventory(viewInv(targetPlayer#));

No problem, just make sure that you understand the code.

EDIT:
and then make sure to clear their own inventory.

@henderry2019 It's unneccecary to use it when you can just use: Inventory#setContents(ItemStack[]);

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