JAVA.LANG.NULLPOINTEREXCEPTION WHEN TRYING TO CREATE GUI

[zombiekiller222]

Java throws a java.lang.NullPointerException when I try to use

player.openGui(LotrCraft.Instance, 1, world, x, y, z);

Doing a little stack-following I found it happens when this code is ran:

 

FMLCommonHandler.instance().showGuiScreen(handler.getClientGuiElement(modGuiId, player, world, x, y, z));

 

So, presumably, my gui handler is returning null? Here is it's code:

 

package mymod.common;

import cpw.mods.fml.common.network.IGuiHandler;
import net.minecraft.src.*;

public class GuiHandler implements IGuiHandler {
@Override
public Object getServerGuiElement(int ID, EntityPlayer player, World world,
int x, int y, int z) {
switch (ID) {
case 1:
return new ContainerSmelter(player.inventory, world, x, y, z);
}
return null;
}

@Override
public Object getClientGuiElement(int ID, EntityPlayer player, World world,
int x, int y, int z) {
switch (ID) {
case 1:
return new GuiSmelter(player.inventory, world, x, y, z);
}
return null;
}
}

 

If you need the code for the container and gui, i'll post it.

[PCChazter]

Do you have

public static GuiHandler guiHandler = new GuiHandler();

 

and

NetworkRegistry.instance().registerGuiHandler(this, guiHandler);

 

added to your main mod file?

[zombiekiller222]

Yes, I do. I did some work and replaced some of mc's code, and now it works:

 

//FMLCommonHandler.instance().showGuiScreen(handler.getClientGuiElement(modGuiId, player, world, x, y, z));
FMLCommonHandler.instance().showGuiScreen(new plantony.lotrcraft.common.GuiHandler().getClientGuiElement(modGuiId, player, world, x, y, z));

 

I don't want it to be like this in the long run (creates incompatibilities).

[PCChazter]

I see, that "handler" variable looks like it should be taken from a List that should have the mod/IGuiHandler relations in it, and

NetworkRegistry.instance().registerGuiHandler(this, guiHandler);

should have populated it correctly.

it giving you a null pointer exception means it was not put in properly. Can you post your main mod file, and the item/block that calls the Gui? Maybe I can see something, maybe not, but I'll give it a shot.

 

Also, make sure you have the latest "recommended" build of Forge, there's always useful updates.