Example usage for java.util Comparator nullsFirst

Introduction

In this page you can find the example usage for java.util Comparator nullsFirst.

Prototype

public static <T> Comparator<T> nullsFirst(Comparator<? super T> comparator) 

Source Link

Document

Returns a null-friendly comparator that considers null to be less than non-null.

Usage

From source file:Main.java

public static void main(String... args) {
    List<String> names2 = Arrays.asList("XML", null, "Java", "HTML", "CSS");
    names2.sort(Comparator.nullsFirst(String::compareTo));
    System.out.println(names2);//from w  w w .j a v a2s .  c  o m

}

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From source file:Main.java

public static void main(String[] args) {
    // Sort the names based on their length, placing null first
    SortedSet<String> names = new TreeSet<>(Comparator.nullsFirst(Comparator.comparing(String::length)));
    names.add("XML");
    names.add("CSS");
    names.add("HTML");
    names.add(null); // Adds a null

    // Print the names
    names.forEach(System.out::println);

}

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From source file:cn.edu.zjnu.acm.judge.contest.ContestController.java

@ResponseBody
@GetMapping(value = "standing", produces = APPLICATION_JSON_VALUE)
public UserStanding[] standing(@PathVariable("contestId") long contestId) {
    Map<String, UserStanding> hashMap = new HashMap<>(80);
    contestMapper.standing(contestId)/*from w  w w  . jav a  2s. c o m*/
            .forEach(standing -> hashMap.computeIfAbsent(standing.getUser(), UserStanding::new)
                    .add(standing.getProblem(), standing.getTime(), standing.getPenalty()));
    contestMapper.attenders(contestId).forEach(attender -> Optional.ofNullable(hashMap.get(attender.getId()))
            .ifPresent(us -> us.setNick(attender.getNick())));
    UserStanding[] standings = hashMap.values().stream().sorted(UserStanding.COMPARATOR)
            .toArray(UserStanding[]::new);
    setIndexes(standings, Comparator.nullsFirst(UserStanding.COMPARATOR), UserStanding::setIndex);
    return standings;
}

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From source file:org.kitodo.production.services.data.ProcessService.java

/**
 * Filter and sort after creation date list of process properties for
 * correction and solution messages./*from w ww  .  j a  v  a  2s  .c o m*/
 *
 * @return list of ProcessProperty objects
 */
public List<PropertyDTO> getSortedCorrectionSolutionMessages(ProcessDTO process) {
    List<PropertyDTO> filteredList = filterForCorrectionSolutionMessages(process.getProperties());

    if (filteredList.size() > 1) {
        filteredList.sort(Comparator.comparing(PropertyDTO::getCreationDate,
                Comparator.nullsFirst(Comparator.naturalOrder())));
    }

    return filteredList;
}

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