One-liner to initialize list from another list

Question

I would like to initialize List of my Dto the shortest way possible. Right now I'm using:

public List<SomeItemDto> itemsToDto(List<SomeItem> items) {
    List<SomeItemDto> itemsDto = new ArrayList<SomeItemDto>();
    for (SomeItem item : items) {
        itemsDto.add(itemToDto(item));
    }
    return itemsDto;
}

Is there any way of making it a one-liner?

Answer 1

You can do it using stream and further mapping as:

return items.stream()
            .map(item -> itemToDto(item)) // map SomeItem to SomeItemDto
            .collect(Collectors.toList());

Answer 2

You can use a map which basically applies a function to an element

List<SomeItemDto> itemsDto = items.stream().map(item -> itemToDto(item))
                                  .collect(Collectors.toList())