NBT

NBT

When we want to edit the nbt of the ItemStack, we usually call nms directly or use reflection.
But this util has done a lot of work for you, you don't need to use reflection anymore.

Normal

When we just want to add some string or integer to item, we can do like this.

TagCompound compound = new TagCompound()
        .putInt("int", 123)
        .putString("string", "§6Test?");

// if you don't want to over ride the nbt, then you can use NBTUtils.getItemStackNBT()
// TagCompound compound = NBTUtils.getItemStackNBT(itemStack)
//      .putInt("int", 123)
//      .putString("string", "§6Test?");

Object nbtTag = compound.build();
System.out.println(nbtTag);
ItemStack itemStack2 = NBTUtils.setItemStackNBT(nbtTag, itemStack);

The output

{
	string: "§6Test?",
	int: 123
}

Attribute

Just see the code..

TagCompound damageTag = new TagCompound()
        .putString("AttributeName", "generic.attackDamage")
        .putString("Name", "Damage")
        .putInt("Amount", 20)
        .putInt("Operation", 0)
        .putInt("UUIDLeast", 20000)
        .putInt("UUIDMost", 1000)
        .putString("Slot", "mainhand");

TagCompound compound = NBTUtils.getItemStackNBT(itemStack)
        .putInt("int", 123)
        .putListCompound("AttributeModifiers", Lists.newArrayList(damageTag));

Object nbtTag = compound.build();
System.out.println(nbtTag);
ItemStack itemStack2 = NBTUtils.setItemStackNBT(nbtTag, itemStack);

The output

{
	int: 123,
	AttributeModifiers: [{
		UUIDMost: 1000,
		UUIDLeast: 20000,
		Amount: 20,
		Slot: "mainhand",
		AttributeName: "generic.attackDamage",
		Operation: 0,
		Name: "Damage"
	}]
}