How to copy Attribute Modifiers to another item?

My Code:
item1.getItemMeta().setAttributeModifiers(item.getItemMeta().getAttributeModifiers());

When i try to use this i have this error:

java: cannot access com.google.common.collect.Multimap
class file for com.google.common.collect.Multimap not found

How can i fix it?

 

That's weird; it works fine for me. Are you sure all your imports are in order?

 

i cant use
import com.google.common.collect.Multimap;
with only Bukkit API, do i need to add another jar to dependencies?

 

I didn't need that one at all. I just fired up my testbed plugin and made it copy attributes from one item to another, worked fine:

Code:

package com.sylvcraft;

import org.bukkit.Material;
import org.bukkit.attribute.Attribute;
import org.bukkit.attribute.AttributeModifier;
import org.bukkit.attribute.AttributeModifier.Operation;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.inventory.ItemStack;
import org.bukkit.inventory.meta.ItemMeta;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;

public class Test118 extends JavaPlugin implements Listener {
  @Override
  public void onEnable() {
    saveDefaultConfig();
    PluginManager pm = getServer().getPluginManager();
    pm.registerEvents(this, this);
  }

  @Override
  public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
    ItemStack i1 = new ItemStack(Material.DIAMOND_SWORD);
    ItemMeta im1 = i1.getItemMeta();
    im1.addAttributeModifier(Attribute.GENERIC_ATTACK_DAMAGE, new AttributeModifier("GENERIC_ATTACK_DAMAGE", 50, Operation.ADD_NUMBER));
    i1.setItemMeta(im1);

    ItemStack i2 = new ItemStack(Material.DIAMOND_SWORD);
    ItemMeta im2 = i2.getItemMeta();
    im2.setAttributeModifiers(im1.getAttributeModifiers());
    i2.setItemMeta(im2);
   
    ((Player)sender).getInventory().addItem(i2);
    return true;
  }
}

 

I tried using your code, but its also not working. I'm using 1.18.2 API if it changes anything