Example usage for java.util.stream Collectors reducing

Introduction

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

Prototype

public static <T> Collector<T, ?, Optional<T>> reducing(BinaryOperator<T> op) 

Source Link

Document

Returns a Collector which performs a reduction of its input elements under a specified BinaryOperator .

Usage

From source file:Main.java

public static void main(String... args) {
    Food o = Food.menu.stream()//ww  w . j a va 2s.  co  m
            .collect(Collectors.reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2)).get();
    System.out.println(o);

}

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From source file:Main.java

public static void main(String... args) {
    Map<Type, Optional<Food>> o = Food.menu.stream().collect(Collectors.groupingBy(Food::getType,
            Collectors.reducing((Food d1, Food d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2)));

    System.out.println(o);/* w  w w. ja v  a 2  s  . c  om*/

}

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From source file:Main.java

public static void main(String... args) {
    Map<Type, Food> o = Food.menu.stream().collect(Collectors.groupingBy(Food::getType,
            Collectors.collectingAndThen(
                    Collectors.reducing((Food d1, Food d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2),
                    Optional::get)));

    System.out.println(o);/*from  w w w.  j  a v  a2s . c om*/

}

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From source file:Main.java

public static void main(String... args) {
    Comparator<Food> dishCaloriesComparator = Comparator.comparingInt(Food::getCalories);
    BinaryOperator<Food> moreCaloricOf = BinaryOperator.maxBy(dishCaloriesComparator);
    Food o = Food.menu.stream().collect(Collectors.reducing(moreCaloricOf)).get();
    System.out.println(o);/*from www.ja va  2 s . c om*/

}

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From source file:Main.java

public static void main(String... args) {
    Stream<Food> menuStream = Food.menu.stream();

    StreamForker.Results results = new StreamForker<Food>(
            menuStream)//from   ww  w. j  ava 2 s.c  o  m
                    .fork("shortMenu", s -> s.map(
                            Food::getName).collect(
                                    Collectors.joining(", ")))
                    .fork("totalCalories", s -> s.mapToInt(Food::getCalories).sum())
                    .fork("mostCaloricFood",
                            s -> s.collect(Collectors
                                    .reducing((d1, d2) -> d1.getCalories() > d2.getCalories() ? d1 : d2)).get())
                    .fork("dishesByType", s -> s.collect(Collectors.groupingBy(Food::getType))).getResults();

    String shortMeny = results.get("shortMenu");
    int totalCalories = results.get("totalCalories");
    Food mostCaloricFood = results.get("mostCaloricFood");
    Map<Food.Type, List<Food>> dishesByType = results.get("dishesByType");

    System.out.println("Short menu: " + shortMeny);
    System.out.println("Total calories: " + totalCalories);
    System.out.println("Most caloric dish: " + mostCaloricFood);
    System.out.println("Foodes by type: " + dishesByType);

}

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From source file:pl.prutkowski.java.playground.java8.TestCollectors.java

/**
 * @param args the command line arguments
 */// ww  w  .j  av  a 2 s  .  c  om
public static void main(String[] args) {
    Map<String, Integer> monthByLen = months.stream()
            .collect(Collectors.toMap(String::toUpperCase, m -> StringUtils.countMatches(m, "e")));

    monthByLen.forEach((month, eCount) -> System.out.println(month + " -> " + eCount));

    System.out.println("---------------------------------");

    Map<Object, List<String>> monthByLen2 = months.stream()
            .collect(Collectors.groupingBy(m -> StringUtils.countMatches(m, "e")));

    monthByLen2.forEach((count, groupedMonths) -> System.out.println(count + " -> " + groupedMonths));

    System.out.println("---------------------------------");

    Double averageLength = months.stream().collect(Collectors.averagingDouble(String::length));
    System.out.println("Average length: " + averageLength);
    System.out.println("---------------------------------");

    Double max = months.stream().collect(Collectors.summarizingDouble(String::length)).getMax();
    System.out.println("Max length: " + max);
    System.out.println("---------------------------------");

    String reduced = months.stream().collect(Collectors.reducing((m1, m2) -> (m1 + ", " + m2))).get();
    System.out.println("Reduced: " + reduced);
    System.out.println("---------------------------------");
    System.out.println(String.join(", ", months));
    System.out.println("---------------------------------");

    List<String> monthsWithZ = months.stream().filter(m -> m.contains("z")).collect(new ListCollector<>());
    System.out.println(monthsWithZ);

}

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From source file:service.UtilsImpl.java

@Override
public String convertPlaysToHtml(List<Play> plays) {
    String body = "";
    Optional<String> opt = plays.stream()
            .map(p -> "                    <tr id=\"" + p.getIdPlay() + "\"" + " onclick=\"fill("
                    + p.getIdPlay() + ")\">\n" + "                       <td style =\"display:none\">"
                    + p.getIdPlay() + "</td>" + "                       <td>" + p.getPlayName() + "</td>\n"
                    + "                       <td>" + p.getStartDate() + "</td>\n"
                    + "                       <td>" + p.getStartTime() + "</td>\n"
                    + "                       <td>" + p.getEndTime() + "</td>\n" + "                       <td>"
                    + p.getTicketPrice() + "</td>\n" + "                    </tr>\n")
            .collect(Collectors.reducing((i, j) -> i + j));
    if (opt.get() != null) {
        body = "            <table id=\"playTable\" class=\"table\" border=1>\n" + "                <thead>\n"
                + "                    <tr>\n" + "                       <th>Name</th>\n"
                + "         <th>Start Date</th>\n" + "         <th>Start Time</th>\n"
                + "         <th>End Time</th>\n" + "         <th>Price</th>\n" + "                    </tr>\n"
                + "                </thead>\n" + "                <tbody>\n";
        body += opt.get();/*from ww  w. j av a2  s .co m*/
        body += "                </tbody>\n            </table>";
    }
    return body;
}

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From source file:service.UtilsImpl.java

@Override
public String convertSeatsToHtml(List<Seat> places) {
    String body = "";
    Optional<String> opt = places.stream().map(p -> "                    <tr id=\"" + p.getIdSeat() + "\">\n"
            + "                       <td style =\"display:none\">" + p.getIdSeat() + "</td>"
            + "                       <td>" + p.getSeatNumber() + "</td>\n" + "                       <td>"
            + p.getAvailability() + "</td>\n" + "                       <td>" + p.getName() + "</td>\n"
            + "                       <td><input type=\"button\" class=\"btn-primary\" onclick=\"reserve("
            + p.getIdSeat() + "," + "'" + p.getAvailability() + "'" + ")\" value=\"reserve\" /></td>"
            + "                       <td><input type=\"button\" class=\"btn-primary\" onclick=\"cancel("
            + p.getIdSeat() + "," + "'" + p.getAvailability() + "'" + ")\" value=\"cancel\" /></td>"
            + "                    </tr>\n").collect(Collectors.reducing((i, j) -> i + j));
    if (opt.get() != null) {
        body = "            <table class=\"table\" border=1>\n" + "                <thead>\n"
                + "                    <tr>\n" + "                       <th>Seat Number</th>\n"
                + "         <th>Availability</th>\n" + "         <th>Name</th>\n"
                + "         <th>Reserve Seat</th>\n" + "         <th>Cancel</th>\n"
                + "                    </tr>\n" + "                </thead>\n" + "                <tbody>\n";
        body += opt.get();//from w ww. j  av a  2s. c  o  m
        body += "                </tbody>\n            </table>";
    }
    return body;
}

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From source file:com.sillelien.dollar.api.types.DollarList.java

@NotNull
@Override/* w w  w. j  a  va2 s.com*/
public ImmutableMap<var, var> toVarMap() {
    AtomicInteger counter = new AtomicInteger();
    return list.stream().map(var -> DollarStatic.$(String.valueOf(counter.getAndIncrement()), var))
            .collect(Collectors.reducing(CollectionAware::$append)).get().toVarMap();
}

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