Java 8: How to get particular value within object inside list without converting stream back to list and fetch value at 0th location?

Question

I need to return value from href() inside a list of links where Rel value is String.

class Links{
    String rel;
    String href;
 }

class 2{
    List<Links> links
 }

Following code is doing so but it is not looking cool

return links.stream().filter(d -> StringUtils.equalsIgnoreCase(d.getRel(), "Self")).collect(Collectors.toList()).get(0).getHref();

Is there any way to fetch getHref directly from list in place of converting it back to list and get 0th element.

Answer 1

Yes, use findFirst():

return links.stream()
            .filter(d -> StringUtils.equalsIgnoreCase(d.getRel(), "Self"))
            .findFirst() // returns an Optional<Links>
            .map(Links::getHref) // returns an Optional<String>
            .orElse(null); // returns String (either getHref of the found Links instance, or
                           // null if no instance passed the filter)