I have this class:

package tlhpoe.fs.item;

import net.minecraft.entity.Entity;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;

public class ItemHermesRing extends Item {
public ItemHermesRing() {
	super();
	setMaxStackSize(1);
	setMaxDamage(100);
}

@Override
public void onUpdate(ItemStack is, World world, Entity entity, int par4, boolean par5) {
	if(!world.isRemote)
		if(entity instanceof EntityPlayer) {
			//EntityPlayer player = (EntityPlayer) entity;
			int dmg = is.getItemDamage();
			switch(dmg) {
			case (99):
				//
				return;
			case (1):
				//
				return;
			}
			System.err.println("SETTING TO 99");
			is.setItemDamage(99);
		}
}

@Override
public ItemStack onItemRightClick(ItemStack is, World w, EntityPlayer player) {
	if(!w.isRemote) {
		int dmg = is.getItemDamage();
		switch(dmg) {
		case (99):
			is.setItemDamage(1);
			return is;
		case (1):
			is.setItemDamage(99);
			return is;
		}
	}
	return is;
}
}

 

For some reason, at this part:

@Override
public ItemStack onItemRightClick(ItemStack is, World w, EntityPlayer player) {
	if(!w.isRemote) {
		int dmg = is.getItemDamage();
		switch(dmg) {
		case (99):
			is.setItemDamage(1);
			return is;
		case (1):
			is.setItemDamage(99);
			return is;
		}
	}
	return is;
}

 

Everytime I right click, it goes directly to case (99). Am I doing something wrong with setting the itemstack's damage?

Well every update tick you are telling it to set the damage to 99, so what did you expect to happen?

If the itemstack's damage is 99 or 1, it returns and doesn't set it to 99.

Check the onUpdate method. It does exactly what Alias said it does as long as the entity is a player.