Java tutorial
/* * Minecraft Forge * Copyright (c) 2016-2019. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation version 2.1 * of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ package net.minecraftforge.items; import net.minecraft.item.ItemStack; import net.minecraft.nbt.INBT; import net.minecraft.nbt.CompoundNBT; import net.minecraft.nbt.ListNBT; import net.minecraft.util.Direction; import net.minecraftforge.common.capabilities.Capability; import net.minecraftforge.common.capabilities.CapabilityInject; import net.minecraftforge.common.capabilities.CapabilityManager; import java.util.concurrent.Callable; public class CapabilityItemHandler { @CapabilityInject(IItemHandler.class) public static Capability<IItemHandler> ITEM_HANDLER_CAPABILITY = null; public static void register() { CapabilityManager.INSTANCE.register(IItemHandler.class, new Capability.IStorage<IItemHandler>() { @Override public INBT writeNBT(Capability<IItemHandler> capability, IItemHandler instance, Direction side) { ListNBT nbtTagList = new ListNBT(); int size = instance.getSlots(); for (int i = 0; i < size; i++) { ItemStack stack = instance.getStackInSlot(i); if (!stack.isEmpty()) { CompoundNBT itemTag = new CompoundNBT(); itemTag.putInt("Slot", i); stack.write(itemTag); nbtTagList.add(itemTag); } } return nbtTagList; } @Override public void readNBT(Capability<IItemHandler> capability, IItemHandler instance, Direction side, INBT base) { if (!(instance instanceof IItemHandlerModifiable)) throw new RuntimeException("IItemHandler instance does not implement IItemHandlerModifiable"); IItemHandlerModifiable itemHandlerModifiable = (IItemHandlerModifiable) instance; ListNBT tagList = (ListNBT) base; for (int i = 0; i < tagList.size(); i++) { CompoundNBT itemTags = tagList.getCompound(i); int j = itemTags.getInt("Slot"); if (j >= 0 && j < instance.getSlots()) { itemHandlerModifiable.setStackInSlot(j, ItemStack.read(itemTags)); } } } }, ItemStackHandler::new); } }