Stream

This week, I learned about a nifty 'new' feature of Optional that I want to share in this post. It’s available since Java 9, so its novelty is relative. Let’s start with the following sequence to compute the total price of an order: public BigDecimal getOrderPrice(Long orderId) { List<OrderLine> lines = orderRepository.findByOrderId(orderId); BigDecimal price = BigDecimal.ZERO; (1) for (OrderLine line : lines) { price = price.add(line.getPrice());