Example usage for java.util.stream Collectors groupingBy

List of usage examples for java.util.stream Collectors groupingBy

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Introduction

In this page you can find the example usage for java.util.stream Collectors groupingBy.

Prototype

public static <T, K, A, D> Collector<T, ?, Map<K, D>> groupingBy(Function<? super T, ? extends K> classifier,
        Collector<? super T, A, D> downstream)

Source Link

Document

Returns a Collector implementing a cascaded "group by" operation on input elements of type T , grouping elements according to a classification function, and then performing a reduction operation on the values associated with a given key using the specified downstream Collector .

Usage

From source file:org.eclipse.collections.impl.jmh.AnagramSetTest.java

@Benchmark
public void serial_lazy_streams_ec() {
    Map<Alphagram, Set<String>> groupBy = this.ecWords.stream()
            .collect(Collectors.groupingBy(Alphagram::new, Collectors.toSet()));
    groupBy.entrySet().stream().map(Map.Entry::getValue).filter(list -> list.size() >= SIZE_THRESHOLD)
            .sorted(Comparator.<Set<String>>comparingInt(Set::size).reversed())
            .map(list -> list.size() + ": " + list).forEach(e -> Assert.assertFalse(e.isEmpty()));
}

From source file:org.eclipse.collections.impl.jmh.AnagramSetTest.java

@Benchmark
public void parallel_lazy_jdk() {
    Map<Alphagram, Set<String>> groupBy = this.jdkWords.parallelStream()
            .collect(Collectors.groupingBy(Alphagram::new, Collectors.toSet()));
    groupBy.entrySet().parallelStream().map(Map.Entry::getValue).filter(list -> list.size() >= SIZE_THRESHOLD)
            .sorted(Comparator.<Set<String>>comparingInt(Set::size).reversed()).parallel()
            .map(list -> list.size() + ": " + list).forEach(e -> Assert.assertFalse(e.isEmpty()));
}

From source file:org.eclipse.collections.impl.jmh.AnagramSetTest.java

@Benchmark
public void parallel_lazy_streams_ec() {
    Map<Alphagram, Set<String>> groupBy = this.ecWords.parallelStream()
            .collect(Collectors.groupingBy(Alphagram::new, Collectors.toSet()));
    groupBy.entrySet().parallelStream().map(Map.Entry::getValue).filter(list -> list.size() >= SIZE_THRESHOLD)
            .sorted(Comparator.<Set<String>>comparingInt(Set::size).reversed()).parallel()
            .map(list -> list.size() + ": " + list).forEach(e -> Assert.assertFalse(e.isEmpty()));
}

From source file:org.efaps.esjp.accounting.Period_Base.java

/**
 * Gets the label definition./*from w  w w .ja  v  a  2  s.c  om*/
 *
 * @param _parameter Parameter as passed by the eFaps API
 * @return the label definition
 * @throws EFapsException on error
 */
@SuppressWarnings("unchecked")
public Return getTargetDocInfo4PaymentFieldValue(final Parameter _parameter) throws EFapsException {
    final Return ret = new Return();
    final String key = Period.class.getName() + ".RequestKey4TargetDocInfo4PaymentFieldValue";
    final Map<Instance, String> values;
    if (Context.getThreadContext().containsRequestAttribute(key)) {
        values = (Map<Instance, String>) Context.getThreadContext().getRequestAttribute(key);
    } else {
        values = new HashMap<>();
        Context.getThreadContext().setRequestAttribute(key, values);
        final List<Instance> instances = (List<Instance>) _parameter.get(ParameterValues.REQUEST_INSTANCES);

        final MultiPrintQuery print = new MultiPrintQuery(instances);
        final SelectBuilder selTargetInsts = SelectBuilder.get().linkfrom(CISales.Payment.TargetDocument)
                .linkto(CISales.Payment.CreateDocument).instance();
        print.addSelect(selTargetInsts);
        print.execute();
        while (print.next()) {
            final List<String> labels = new ArrayList<>();
            final Object obj = print.getSelect(selTargetInsts);
            if (obj != null) {
                final List<Instance> targetInsts;
                if (obj instanceof Instance) {
                    targetInsts = new ArrayList<>();
                    targetInsts.add((Instance) obj);
                } else {
                    targetInsts = (List<Instance>) obj;
                }
                for (final Instance targetInst : targetInsts) {
                    final SelectBuilder selActName;
                    if (InstanceUtils.isType(targetInst, CISales.PaymentOrder)) {
                        selActName = SelectBuilder.get()
                                .linkfrom(CISales.ActionDefinitionPaymentOrder2Document.ToLinkAbstract)
                                .linkto(CISales.ActionDefinitionPaymentOrder2Document.FromLinkAbstract)
                                .attribute(CISales.ActionDefinitionPaymentOrder.Name);

                    } else if (InstanceUtils.isType(targetInst, CISales.CollectionOrder)) {
                        selActName = SelectBuilder.get()
                                .linkfrom(CISales.ActionDefinitionCollectionOrder2Document.ToLinkAbstract)
                                .linkto(CISales.ActionDefinitionCollectionOrder2Document.FromLinkAbstract)
                                .attribute(CISales.ActionDefinitionCollectionOrder.Name);

                    } else if (InstanceUtils.isType(targetInst, CISales.IncomingExchange)) {
                        selActName = SelectBuilder.get()
                                .linkfrom(CISales.ActionDefinitionIncomingExchange2Document.ToLinkAbstract)
                                .linkto(CISales.ActionDefinitionIncomingExchange2Document.FromLinkAbstract)
                                .attribute(CISales.ActionDefinitionIncomingExchange.Name);

                    } else {
                        selActName = null;
                    }

                    if (selActName != null) {
                        final PrintQuery print2 = new PrintQuery(targetInst);
                        print2.addSelect(selActName);
                        print2.execute();

                        final String actname = print2.getSelect(selActName);
                        if (actname == null) {
                            labels.add(targetInst.getType().getLabel());
                        } else {
                            labels.add(targetInst.getType().getLabel() + " - " + actname);
                        }
                    } else {
                        labels.add(targetInst.getType().getLabel());
                    }
                }
                final Map<String, Long> map = labels.stream()
                        .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));
                final StringBuilder bldr = new StringBuilder();
                for (final Entry<String, Long> entry : map.entrySet()) {
                    if (bldr.length() > 0) {
                        bldr.append(", ");
                    }
                    bldr.append(entry.getValue()).append(" x ").append(entry.getKey());
                }
                values.put(print.getCurrentInstance(), bldr.toString());
            }
        }
    }
    ret.put(ReturnValues.VALUES, values.get(_parameter.getInstance()));
    return ret;
}

From source file:org.gradoop.flink.model.impl.operators.matching.common.query.QueryHandler.java

/**
 * Initializes a cache for the given elements where every key maps to multiple elements.
 * Key selector will be called on every element to extract the caches key.
 * Value selector will be called on every element to extract the value.
 * Returns a cache of the form//from   ww  w.j  ava  2 s . c  o  m
 * KT -> Set<VT>
 *
 * @param elements elements the cache will be build from
 * @param keySelector key selector function extraction cache keys from elements
 * @param valueSelector value selector function extraction cache values from elements
 * @param <EL> the element type
 * @param <KT> the cache key type
 * @param <VT> the cache value type
 * @return cache KT -> Set<VT>
 */
private <EL, KT, VT> Map<KT, Set<VT>> initSetCache(Collection<EL> elements, Function<EL, KT> keySelector,
        Function<EL, VT> valueSelector) {

    return elements.stream()
            .collect(Collectors.groupingBy(keySelector, Collectors.mapping(valueSelector, Collectors.toSet())));
}

From source file:org.languagetool.rules.spelling.SpellingCheckRule.java

private void updateIgnoredWordDictionary() {
    wordsToBeIgnoredDictionary = wordsToBeIgnored.stream()
            .collect(Collectors.groupingBy(s -> s.substring(0, 1), Collectors.toSet()));
    wordsToBeIgnoredDictionaryIgnoreCase = wordsToBeIgnored.stream().map(String::toLowerCase)
            .collect(Collectors.groupingBy(s -> s.substring(0, 1), Collectors.toSet()));
}

From source file:org.onosproject.faultmanagement.impl.AlarmManager.java

@Override
public Map<Alarm.SeverityLevel, Long> getAlarmCounts(DeviceId deviceId) {
    return getAlarms(deviceId).stream().collect(Collectors.groupingBy(Alarm::severity, Collectors.counting()));
}

From source file:org.onosproject.faultmanagement.impl.AlarmManager.java

@Override
public Map<Alarm.SeverityLevel, Long> getAlarmCounts() {
    return getAlarms().stream().collect(Collectors.groupingBy(Alarm::severity, Collectors.counting()));
}

From source file:org.onosproject.faultmanagement.impl.AlarmsManager.java

@Override
public Map<Alarm.SeverityLevel, Long> getAlarmCounts(DeviceId deviceId) {

    return getAlarms(deviceId).stream().collect(Collectors.groupingBy(Alarm::severity, Collectors.counting()));

}

From source file:org.onosproject.faultmanagement.impl.AlarmsManager.java

@Override
public Map<Alarm.SeverityLevel, Long> getAlarmCounts() {

    return getAlarms().stream().collect(Collectors.groupingBy(Alarm::severity, Collectors.counting()));
}