How to sort object using java 8 streams

Question

I am using the stream API in java 8 to handle my collections. However, I am wondering what would be an elegant way to sort my objects in a given order, using this API.

SortedCollection = inputCollection.stream()
    .map(e -> {
        return new Element(e.id, e.color);
    }).collect(Collectors.toList());

Here I would like to sort the elements that have been mapped, using the id attribute.

Any idea ? Thanks !

Answer 1

Simply use Stream#sorted as follows with the name of your getter method for the Element's ID.

inputCollection.stream()
               .map(e -> new Element(e.id, e.color))
               .sorted(Comparator.comparing(Element::getId))
               .collect(Collectors.toList());