And how to add 2 enchantments at once in bukkit with
myItem.addEnchantments( Enchantment.KNOCKBACK, 1 /* TODO Here goes 2nd enchantment */ );
'addEnchantments' accepts 'addEnchantments(Map < Enchantment, int >)'
You rather use addEnchantment
twice (or more):
myItem.addEnchantment(Enchantment.KNOCKBACK, 1);
myItem.addEnchantment(Enchantment.THRONS, 2);
If you insist on using addEnchantments
you'll need to create a map, populate it and pass it:
Map<Enhancement, Integer> map = new HashMap<Enhancement, Integer>();
map.put(Enchantment.KNOCKBACK, 1);
map.put(Enchantment.THRONS, 2);
myItem.addEnchantments(map);
In your case, I would go with option 1