[1.14.4] ReportedException: Saving entity NBT

[andGarrett]

I get a NullPointerException every time I load a game with my new capability:

 

[21:11:11.880] [Server thread/INFO] [minecraft/MinecraftServer]: Dev joined the game
[21:11:12.204] [Client thread/INFO] [minecraft/AdvancementList]: Loaded 0 advancements
[21:11:12.749] [Server thread/INFO] [minecraft/IntegratedServer]: Saving and pausing game...
[21:11:12.751] [Server thread/ERROR] [minecraft/MinecraftServer]: Encountered an unexpected exception
net.minecraft.crash.ReportedException: Saving entity NBT
    at net.minecraft.entity.Entity.writeWithoutTypeId(Entity.java:1592) ~[?:?] {pl:accesstransformer:B}
    at net.minecraft.server.integrated.IntegratedPlayerList.writePlayerData(IntegratedPlayerList.java:27) ~[?:?] {pl:runtimedistcleaner:A}
    at net.minecraft.server.management.PlayerList.saveAllPlayerData(PlayerList.java:624) ~[?:?] {}
    at net.minecraft.server.integrated.IntegratedServer.tick(IntegratedServer.java:112) ~[?:?] {pl:runtimedistcleaner:A}
    at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:646) [?:?] {pl:accesstransformer:B}
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_221] {}
Caused by: java.lang.NullPointerException
    at com.garrett.backtobasics.capabilities.BankAccount.BankAccountProvider.serializeNBT(BankAccountProvider.java:36) ~[?:?] {}
    at net.minecraftforge.common.capabilities.CapabilityDispatcher.serializeNBT(CapabilityDispatcher.java:127) ~[?:?] {}
    at net.minecraftforge.common.capabilities.CapabilityProvider.serializeCaps(CapabilityProvider.java:86) ~[?:?] {}
    at net.minecraft.entity.Entity.writeWithoutTypeId(Entity.java:1567) ~[?:?] {pl:accesstransformer:B}

 

Here is the line that causes the exception:

return BANK_ACCOUNT_CAPABILITY.getStorage().writeNBT(BANK_ACCOUNT_CAPABILITY, holder.orElseThrow(nonNullSupplier), null);

 

it happens in line 36 of this class:

package com.garrett.backtobasics.capabilities.BankAccount;

import net.minecraft.nbt.INBT;
import net.minecraft.util.Direction;
import net.minecraftforge.common.capabilities.Capability;
import net.minecraftforge.common.capabilities.CapabilityInject;
import net.minecraftforge.common.capabilities.ICapabilitySerializable;
import net.minecraftforge.common.util.LazyOptional;
import net.minecraftforge.common.util.NonNullSupplier;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

public class BankAccountProvider implements ICapabilitySerializable<INBT> {

    @CapabilityInject(BankAccountCapability.class)
    public static Capability<BankAccountCapability> BANK_ACCOUNT_CAPABILITY = null;

    private final LazyOptional<BankAccountCapability> holder = LazyOptional.of(BankAccountCapability::new);

    @Nonnull
    @Override
    public <T> LazyOptional<T> getCapability(@Nonnull Capability<T> cap, @Nullable Direction side) {
        return BANK_ACCOUNT_CAPABILITY.orEmpty(cap, holder);
    }

    @Override
    public INBT serializeNBT() {
        NonNullSupplier<? extends NullPointerException> nonNullSupplier = new NonNullSupplier<NullPointerException>() {
            @Nonnull
            @Override
            public NullPointerException get() {
                return null;
            }
        };
        return BANK_ACCOUNT_CAPABILITY.getStorage().writeNBT(BANK_ACCOUNT_CAPABILITY, holder.orElseThrow(nonNullSupplier), null);
    }

    @Override
    public void deserializeNBT(INBT nbt) {
        NonNullSupplier<? extends NullPointerException> nonNullSupplier = new NonNullSupplier<NullPointerException>() {
            @Nonnull
            @Override
            public NullPointerException get() {
                return null;
            }
        };
        BANK_ACCOUNT_CAPABILITY.getStorage().readNBT(BANK_ACCOUNT_CAPABILITY, holder.orElseThrow(nonNullSupplier), null, nbt);
    }
}

 

 

it's my first time creating a capability that attaches to players as apposed to the world, so I may have missed an extra step that might need to be taken when attaching capabilities to players. here is where I do the attaching:

package com.garrett.backtobasics.capabilities;

import com.garrett.backtobasics.BackToBasics;
import com.garrett.backtobasics.capabilities.BankAccount.BankAccountProvider;
import com.garrett.backtobasics.capabilities.blockpopulation.BlockPopulationProvider;
import com.garrett.backtobasics.capabilities.itemvalues.ItemValuesProvider;
import com.garrett.backtobasics.capabilities.saleitemlist.SaleItemListProvider;
import net.minecraft.entity.Entity;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.util.ResourceLocation;
import net.minecraft.world.World;
import net.minecraftforge.event.AttachCapabilitiesEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;

/**
 * Event handler used to attach capabilities
 */
public class BackToBasicsEventHandler {

    public static final ResourceLocation BLOCK_POPULATION_CAPABILITY = new ResourceLocation(BackToBasics.MODID, "block_population");
    public static final ResourceLocation BANK_ACCOUNT_CAPABILITY = new ResourceLocation(BackToBasics.MODID, "bank_account");
    public static final ResourceLocation ITEM_VALUES_CAPABILITY = new ResourceLocation(BackToBasics.MODID, "item_values");
    public static final ResourceLocation SALE_ITEM_LIST_CAPABILITY = new ResourceLocation(BackToBasics.MODID, "sale_item_list");

    @SubscribeEvent
    public void attachWorldCapability(AttachCapabilitiesEvent<World> event)
    {
        event.addCapability(BLOCK_POPULATION_CAPABILITY, new BlockPopulationProvider());
        event.addCapability(ITEM_VALUES_CAPABILITY, new ItemValuesProvider());

    }
    @SubscribeEvent
    public void attachEntityCapability(AttachCapabilitiesEvent<Entity> event)
    {
        if (event.getObject() instanceof PlayerEntity) {
            event.addCapability(BANK_ACCOUNT_CAPABILITY, new BankAccountProvider());
            event.addCapability(SALE_ITEM_LIST_CAPABILITY, new SaleItemListProvider());
        }
    }
}

 

[Animefan8888]

1 hour ago, andGarrett said:

@Nonnull @Override public NullPointerException get() {   return null;

I'm sorry what? Its Nonnull and part of a NonNullSupplier but you're returning null...

 

Also did you make sure to register your Capability.

[andGarrett]

2 hours ago, Animefan8888 said:

Also did you make sure to register your Capability.

ah, yup. now it works.

 

2 hours ago, Animefan8888 said:

I'm sorry what? Its Nonnull and part of a NonNullSupplier but you're returning null...

 

It's very difficult to find information on how to create custom capabilities in 1.14. When I was first trying to learn how to create a custom capability, I threw a lot of spaghetti code at it just to figure things out. At some point I knew I needed a NonNullSupplier for holder.orelsethrow(???). so I created one and here's what Intellij gave me by default:

 

        NonNullSupplier<? extends NullPointerException> nonNullSupplier = new NonNullSupplier<NullPointerException>() {
            @Nonnull
            @Override
            public NullPointerException get() {
                return null;
            }
        }

 

it returns null by default. Not knowing what it should actually be returning, I left it the way it was, and hey, it seemed to work. I didn't question it, because I know nothing about NonNullSuppliers. What should I be doing instead?

[andGarrett]

16 hours ago, diesieben07 said:

Please, please, please read the Javadocs on the methods you are using. orElseThrow explains all this in it's Javadoc. It even gives you a ready to copy example. People (you included!) complain that there is no documentation. Yes, documentation is often scarce. But if it's there you gotta f***ing read it.

Please forgive my lack of java knowledge. I don't always realize something like an optional is part of java as opposed to forge/minecraft. if I had known, I would have looked into it as you suggested. I'm using minecraft modding as a way to get a deeper understanding of java. I learned java on code academy, because I don't have the money to go to college to learn java properly, and I don't have a mentor to help me. this has left many unknown gaps in my knowledge. sometimes I don't even know what I am lacking.

 

I greatly appreciate all the help you and the others have given me. That being said, I must ask you to remember that helping people like me is always optional, and hostility helps no one. We are all human.

[andGarrett]

5 hours ago, diesieben07 said:

LazyOptional is part of Forge. I never said it wasn't. I just told you to read it's Javadocs. Javadocs are the documentation above methods, fields, classes, etc. It has nothing to do from which library something is.

I was referring to " optional.orElseThrow".

[andGarrett]

2 hours ago, diesieben07 said:

Since optional in this case is referring to a LazyOptional it's still part of Forge.

oh, that's right I forgot it was for LazyOptional, not just the regular optional.