인벤토리에 있는 다이아를 두 배하고 싶어서요

@EventHandler
public void PlayerOnRightclick(PlayerInteractEvent e) {
    Player p = e.getPlayer();
    if(e.getAction().equals(Action.RIGHT_CLICK_AIR) && e.getClickedBlock().getType().equals(Material.DIAMOND)) {
        p.sendMessage("you copied DIA");
        Bukkit.getConsoleSender().sendMessage("Who copied DIA");

    }
}