snippet_itemspec.java

ItemStack dummy = new ItemStack(Material.AIR);

Iterable<String> split = Splitter.on(',').trimResults().omitEmptyStrings().split("276:2, 10, §3Sei la, DAMAGE_ALL:5, FIRE_ASPECT:2");
Spliterator<String> it = split.spliterator();

/* Id e data */
it.tryAdvance(raw -> {
  String[] rawSpl = raw.split(":"); // 0 = id, 1 = data
  dummy.setTypeId(Integer.parseInt(rawSpl[0]));
  dummy.getData().setData(Byte.parseByte(rawSpl[1]));
});

ItemMeta dummyMeta = dummy.getItemMeta();

/* Quantidade */
it.tryAdvance(amt -> dummy.setAmount(Integer.valueOf(amt)));

/* DisplayName */
it.tryAdvance(dummyMeta::setDisplayName);

/* Enchantments */
it.forEachRemaining(rawEnch -> {
  String[] rawSpl = rawEnch.split(":");
  dummy.addEnchantment(Enchantment.getByName(rawSpl[0]),
      Short.parseShort(rawSpl[1]));
});

dummy.setItemMeta(dummyMeta);