java.util.stream.Collectors.collectingAndThen()方法的使用及代码示例

x33g5p2x  于2022-01-17 转载在 其他  
字(9.5k)|赞(0)|评价(0)|浏览(261)

本文整理了Java中java.util.stream.Collectors.collectingAndThen()方法的一些代码示例，展示了Collectors.collectingAndThen()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Collectors.collectingAndThen()方法的具体详情如下：
包路径：java.util.stream.Collectors
类名称：Collectors
方法名：collectingAndThen

Collectors.collectingAndThen介绍

暂无

代码示例

代码示例来源：origin: google/guava

  1. /**
  2.  * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys
  3.  * and values are the result of applying the provided mapping functions to the input elements.
  4.  *
  5.  * <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}), the
  6.  * values are merged using the specified merging function. Entries will appear in the encounter
  7.  * order of the first occurrence of the key.
  8.  *
  9.  * @since 21.0
  10.  */
  11. @Beta
  12. public static <T, K, V> Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
  13.   Function<? super T, ? extends K> keyFunction,
  14.   Function<? super T, ? extends V> valueFunction,
  15.   BinaryOperator<V> mergeFunction) {
  16.  checkNotNull(keyFunction);
  17.  checkNotNull(valueFunction);
  18.  checkNotNull(mergeFunction);
  19.  return Collectors.collectingAndThen(
  20.    Collectors.toMap(keyFunction, valueFunction, mergeFunction, LinkedHashMap::new),
  21.    ImmutableMap::copyOf);
  22. }

代码示例来源：origin: apache/kafka

  1. public static <T> List<T> concatLists(List<T> left, List<T> right, Function<List<T>, List<T>> finisher) {
  2.   return Stream.concat(left.stream(), right.stream())
  3.       .collect(Collectors.collectingAndThen(Collectors.toList(), finisher));
  4. }

代码示例来源：origin: google/guava

  1. /**
  2.  * Returns a {@link Collector} that accumulates elements into an {@code ImmutableSortedMap} whose
  3.  * keys and values are the result of applying the provided mapping functions to the input
  4.  * elements.
  5.  *
  6.  * <p>If the mapped keys contain duplicates (according to the comparator), the the values are
  7.  * merged using the specified merging function. Entries will appear in the encounter order of the
  8.  * first occurrence of the key.
  9.  *
  10.  * @since 21.0
  11.  */
  12. @Beta
  13. public static <T, K, V> Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
  14.   Comparator<? super K> comparator,
  15.   Function<? super T, ? extends K> keyFunction,
  16.   Function<? super T, ? extends V> valueFunction,
  17.   BinaryOperator<V> mergeFunction) {
  18.  checkNotNull(comparator);
  19.  checkNotNull(keyFunction);
  20.  checkNotNull(valueFunction);
  21.  checkNotNull(mergeFunction);
  22.  return Collectors.collectingAndThen(
  23.    Collectors.toMap(
  24.      keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),
  25.    ImmutableSortedMap::copyOfSorted);
  26. }

代码示例来源：origin: speedment/speedment

  1. public static <T> Collector<T, ?, List<T>> toReversedList() {
  2.   return Collectors.collectingAndThen(Collectors.toList(), l -> {
  3.     Collections.<T>reverse(l);
  4.     return l;
  5.   });
  6. }

代码示例来源：origin: knowm/XChange

  1. public static <T> Collector<T, ?, T> singletonCollector() {
  2.   return Collectors.collectingAndThen(
  3.     Collectors.toList(),
  4.     list -> {
  5.      if (list.size() > 1) {
  6.       throw new IllegalStateException("List contains more than one element: " + list);
  7.      }
  8.      return list.size() > 0 ? list.get(0) : null;
  9.     });
  10.  }
  11. }

代码示例来源：origin: SonarSource/sonarqube

  1. /**
  2.  * For stream of one expected element, return the element
  3.  *
  4.  * @throws IllegalArgumentException if stream has no element or more than 1 element
  5.  */
  6. public static <T> Collector<T, ?, T> toOneElement() {
  7.  return java.util.stream.Collectors.collectingAndThen(
  8.   java.util.stream.Collectors.toList(),
  9.   list -> {
  10.    if (list.size() != 1) {
  11.     throw new IllegalStateException("Stream should have only one element");
  12.    }
  13.    return list.get(0);
  14.   });
  15. }

代码示例来源：origin: apache/incubator-druid

  1. private List<String> prepareDimensionsOrMetrics(@Nullable List<String> list, Interner<List<String>> interner)
  2. {
  3.  if (list == null) {
  4.   return ImmutableList.of();
  5.  } else {
  6.   List<String> result = list
  7.     .stream()
  8.     .filter(s -> !Strings.isNullOrEmpty(s))
  9.     // dimensions & metrics are stored as canonical string values to decrease memory required for storing
  10.     // large numbers of segments.
  11.     .map(STRING_INTERNER::intern)
  12.     // TODO replace with ImmutableList.toImmutableList() when updated to Guava 21+
  13.     .collect(Collectors.collectingAndThen(Collectors.toList(), ImmutableList::copyOf));
  14.   return interner.intern(result);
  15.  }
  16. }

代码示例来源：origin: speedment/speedment

  1. /**
  2.  * Creates and returns a new unmodifiable list of immutable Stage object
  3.  *
  4.  * @return a new unmodifiable list of immutable Stage object
  5.  */
  6. List<Stage<?>> stages() {
  7.   resolveStages();
  8.   return stageBeans.stream()
  9.     .map(StageBean::asStage)
  10.     .collect(collectingAndThen(toList(), Collections::unmodifiableList));
  11. }

代码示例来源：origin: graphhopper/graphhopper

  1. static List<SanitizedFareRule> sanitizeFareRules(List<FareRule> gtfsFareRules) {
  2.   // Make proper fare rule objects from the CSV-like FareRule
  3.   ArrayList<SanitizedFareRule> result = new ArrayList<>();
  4.   result.addAll(gtfsFareRules.stream().filter(rule -> rule.route_id != null).map(rule -> new RouteRule(rule.route_id)).collect(toList()));
  5.   result.addAll(gtfsFareRules.stream().filter(rule -> rule.origin_id != null && rule.destination_id != null).map(rule -> new OriginDestinationRule(rule.origin_id, rule.destination_id)).collect(toList()));
  6.   result.add(gtfsFareRules.stream().filter(rule -> rule.contains_id != null).map(rule -> rule.contains_id).collect(Collectors.collectingAndThen(toList(), ZoneRule::new)));
  7.   return result;
  8. }

代码示例来源：origin: pmd/pmd

  1. AstPackageExplorer(Language language) {
  2.   availableNodeNames =
  3.     getClassesInPackage("net.sourceforge.pmd.lang." + language.getTerseName() + ".ast")
  4.       .filter(clazz -> clazz.getSimpleName().startsWith("AST"))
  5.       .filter(clazz -> !clazz.isInterface() && !Modifier.isAbstract(clazz.getModifiers()))
  6.       .map(m -> m.getSimpleName().substring("AST".length()))
  7.       .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));
  8. }

代码示例来源：origin: org.assertj/assertj-core

  1. private <T> List<T> simplePropertyValues(String propertyName, Class<T> clazz, Iterable<?> target) {
  2.  return stream(target).map(e -> e == null ? null : propertyValue(propertyName, clazz, e))
  3.             .collect(collectingAndThen(toList(), Collections::unmodifiableList));
  4. }

代码示例来源：origin: hs-web/hsweb-framework

  1. @Override
  2.   public TaskEventListener getTaskListener(String eventType) {
  3.     if (CollectionUtils.isEmpty(configEntity.getListeners())) {
  4.       return null;
  5.     }
  6.     return configEntity
  7.         .getListeners()
  8.         .stream()
  9.         .filter(config -> eventType.equals(config.getEventType()))
  10.         .map(ProcessConfigurationServiceImpl.this::<TaskEvent>createTaskEventListener)
  11.         .collect(Collectors.collectingAndThen(Collectors.toList(),
  12.             list -> event -> list.forEach(listener -> listener.accept(event))));
  13.   }
  14. };

代码示例来源：origin: prestodb/presto

  1. public Expression toPredicate(TupleDomain<Symbol> tupleDomain)
  2. {
  3.   if (tupleDomain.isNone()) {
  4.     return FALSE_LITERAL;
  5.   }
  6.   Map<Symbol, Domain> domains = tupleDomain.getDomains().get();
  7.   return domains.entrySet().stream()
  8.       .sorted(comparing(entry -> entry.getKey().getName()))
  9.       .map(entry -> toPredicate(entry.getValue(), entry.getKey().toSymbolReference()))
  10.       .collect(collectingAndThen(toImmutableList(), ExpressionUtils::combineConjuncts));
  11. }

代码示例来源：origin: org.assertj/assertj-core

  1. private <T> List<T> simpleFieldValues(String fieldName, Class<T> clazz, Iterable<?> target) {
  2.  return stream(target).map(e -> e == null ? null : fieldValue(fieldName, clazz, e))
  3.             .collect(collectingAndThen(toList(), Collections::unmodifiableList));
  4. }

代码示例来源：origin: hs-web/hsweb-framework

  1. @Override
  2.   public ProcessEventListener getProcessListener(String eventType) {
  3.     if (CollectionUtils.isEmpty(entity.getListeners())) {
  4.       return null;
  5.     }
  6.     return entity
  7.         .getListeners()
  8.         .stream()
  9.         .filter(config -> eventType.equals(config.getEventType()))
  10.         .map(ProcessConfigurationServiceImpl.this::<ProcessEvent>createTaskEventListener)
  11.         .collect(Collectors.collectingAndThen(Collectors.toList(),
  12.             list -> event -> list.forEach(listener -> listener.accept(event))));
  13.   }
  14. };

代码示例来源：origin: google/guava

  1. checkNotNull(keyFunction);
  2. checkNotNull(valuesFunction);
  3. return Collectors.collectingAndThen(
  4.   Multimaps.flatteningToMultimap(
  5.     input -> checkNotNull(keyFunction.apply(input)),

代码示例来源：origin: google/guava

  1. checkNotNull(keyFunction);
  2. checkNotNull(valuesFunction);
  3. return Collectors.collectingAndThen(
  4.   Multimaps.flatteningToMultimap(
  5.     input -> checkNotNull(keyFunction.apply(input)),

代码示例来源：origin: google/error-prone

  1. private static Collector<JCVariableDecl, ?, ImmutableMultimap<Integer, JCVariableDecl>>
  2.   collectByEditDistanceTo(String baseName) {
  3.  return Collectors.collectingAndThen(
  4.    Multimaps.toMultimap(
  5.      (JCVariableDecl varDecl) ->
  6.        LevenshteinEditDistance.getEditDistance(baseName, varDecl.name.toString()),
  7.      varDecl -> varDecl,
  8.      LinkedHashMultimap::create),
  9.    ImmutableMultimap::copyOf);
  10. }

代码示例来源：origin: graphql-java/graphql-java

  1. public CompletableFuture<List<Project>> getProjectsForCompanies(List<UUID> companyIds) {
  2.   return CompletableFuture.supplyAsync(() -> projects.values().stream()
  3.       .filter(project -> companyIds.contains(project.getCompanyId()))
  4.       .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList)));
  5. }

代码示例来源：origin: prestodb/presto

  1. /**
  2.  * Returns a {@link Collector} that accumulates elements into an {@code ImmutableMap} whose keys
  3.  * and values are the result of applying the provided mapping functions to the input elements.
  4.  *
  5.  * <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}), the
  6.  * values are merged using the specified merging function. Entries will appear in the encounter
  7.  * order of the first occurrence of the key.
  8.  *
  9.  * @since 21.0
  10.  */
  11. @Beta
  12. public static <T, K, V> Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
  13.   Function<? super T, ? extends K> keyFunction,
  14.   Function<? super T, ? extends V> valueFunction,
  15.   BinaryOperator<V> mergeFunction) {
  16.  checkNotNull(keyFunction);
  17.  checkNotNull(valueFunction);
  18.  checkNotNull(mergeFunction);
  19.  return Collectors.collectingAndThen(
  20.    Collectors.toMap(keyFunction, valueFunction, mergeFunction, LinkedHashMap::new),
  21.    ImmutableMap::copyOf);
  22. }

内容来源于网络，如有侵权，请联系作者删除！

Collectors

相关文章

    查看更多

    热门标签

    更多
    JavaquerypythonNode开发语言requestUtil数据库Table后端算法LoggerMessageElementParser

    最新文章

    更多
    • 蜀ICP备13028337号-1 大数据知识库 https://www.saoniuhuo.com © All rights reserved
    • 本站内容来源互联网,如果侵犯您的权益请联系我们删除, 联系方式：448109455@qq.com