One-liner to initialize list from another list

You can do it using stream and further mapping as:

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

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())

If you are open to using a third-party library, you can use the ListIterate utility from Eclipse Collections with any List.

List<SomeItemDto> itemsDto = ListIterate.collect(items, this::itemToDto);

If items was a MutableList from Eclipse Collections, you could use the API directly on the list as follows:

List<SomeItemDto> itemsDto = items.collect(this::itemToDto);

Note: I am a committer for Eclipse Collections.

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