Class Loader API

pass the api the package/folder your items or entities are in, and it will search that folder the item or entity, pass any parameters you provide it and load them into the game.

e.g.

yourMainClass.java

@EventHandler
    public void preinit(FMLPreInitializationEvent event)
    {
        CLAPI clap = new CLAPI();
        items = clap.getItems("nz.co.crookedhill.items");

        registerItems(items);
    }

private void registerItems(Map<String, Item>items)

{

        for(Map.Entry<String, Item> entry : items.entrySet())

        {

                GameRegistry.registerItem(entry.getValue(), entry.getKey());

        }

}

 and thats it, all 100 of your items, registered cleanly.