Stream流與Lambda表達式(三) 靜態工廠類Collectors

/**
 * @author 陳楊
 */

@SpringBootTest
@RunWith(SpringRunner.class)
public class CollectorsDetail {

    private List<String> names;
    private List<Student> students;
    private List<List<String>> snames;

    @Before
    public void init() {

        names = Arrays.asList("Kirito", "Asuna", "Sinon", "Yuuki", "Alice");
        snames = Arrays.asList(Collections.singletonList("Kirito"), Collections.singletonList("Asuna"),
                Collections.singletonList("Sinon"), Collections.singletonList("Yuuki"),
                Collections.singletonList("Alice"));

        students = new Students().init();
    }

    @Test
    public void testCollectorsDetail() {

一、靜態工廠類Collectors 實現方式

//    一、靜態工廠類Collectors 實現方式

//    Collectors 靜態工廠類   最終由CollectorImpl實現
//       1、 通過CollectorImpl實現
//       2、 通過reducing()實現---> reducing()底層由CollectorImpl實現


//    Collectors.toList()  是 Collectors.toCollection()的一種具化表現形式
//    Collectors.joining() 使用StringBuilder.append 拼接字符串

二、靜態工廠類Collectors 常用收集器

//    二、靜態工廠類Collectors 常用收集器

/*
      返回一個(不可修改)unmodifiable List的ArrayList  按照相遇的順序encounter order
@since 10
@SuppressWarnings("unchecked")
public static <T>
        Collector<T, ?, List<T>> toUnmodifiableList() {
    return new CollectorImpl<>((Supplier<List<T>>) ArrayList::new, List::add,
            (left, right) -> { left.addAll(right); return left; },
            list -> (List<T>)List.of(list.toArray()),
            CH_NOID);
}*/


/*
      返回一個(不可修改)unmodifiable Set的HashSet 無序
@since 10
@SuppressWarnings("unchecked")
public static <T>
        Collector<T, ?, Set<T>> toUnmodifiableSet() {
    return new CollectorImpl<>((Supplier<Set<T>>) HashSet::new, Set::add,
            (left, right) -> {
                if (left.size() < right.size()) {
                    right.addAll(left); return right;
                } else {
                    left.addAll(right); return left;
                }
            },
            set -> (Set<T>)Set.of(set.toArray()),
            CH_UNORDERED_NOID);
}
*/


/*
      返回一個flatMapping扁平化mapper處理後 由downstream收集的 累加器處理的結果合併  單線程
@since 9
public static <T, U, A, R>
        Collector<T, ?, R> flatMapping(Function<? super T, ? extends Stream<? extends U>> mapper,
        Collector<? super U, A, R> downstream) {
    BiConsumer<A, ? super U> downstreamAccumulator = downstream.accumulator();
    return new CollectorImpl<>(downstream.supplier(),
            (r, t) -> {
                try (Stream<? extends U> result = mapper.apply(t)) {
                    if (result != null)
                        result.sequential().forEach(u -> downstreamAccumulator.accept(r, u));
                }
            },
            downstream.combiner(), downstream.finisher(),
            downstream.characteristics());
}*/



/*
      對符合Predicate預期結果 進行過濾filtering 使用downstream 收集元素
@since 9
public static <T, A, R>
        Collector<T, ?, R> filtering(Predicate<? super T> predicate,
        Collector<? super T, A, R> downstream) {
    BiConsumer<A, ? super T> downstreamAccumulator = downstream.accumulator();
    return new CollectorImpl<>(downstream.supplier(),
            (r, t) -> {
                if (predicate.test(t)) {
                    downstreamAccumulator.accept(r, t);
                }
            },
            downstream.combiner(), downstream.finisher(),
            downstream.characteristics());
}*/


/*
      使用Map映射key-->keyMapper-->Key value-->valueMapper-->Value
      對映射後的結果進行組裝entrySet-->Map<Key,Value> (unmodifiable Map)
@since 10
@SuppressWarnings({"rawtypes", "unchecked"})
public static <T, K, U>
        Collector<T, ?, Map<K,U>> toUnmodifiableMap(Function<? super T, ? extends K> keyMapper,
        Function<? super T, ? extends U> valueMapper) {
    Objects.requireNonNull(keyMapper, "keyMapper");
    Objects.requireNonNull(valueMapper, "valueMapper");
    return collectingAndThen(
            toMap(keyMapper, valueMapper),
            map -> (Map<K,U>)Map.ofEntries(map.entrySet().toArray(new Map.Entry[0])));
}*/


/*
      使用Map映射key-->keyMapper-->Key value-->valueMapper-->Value
      mergeFunction 對相同key 映射後的進行Value 合併操作
      對映射後的結果進行組裝entrySet-->Map<Key,Value> (unmodifiable Map)

@since 10
@SuppressWarnings({"rawtypes", "unchecked"})
public static <T, K, U>
        Collector<T, ?, Map<K,U>> toUnmodifiableMap(Function<? super T, ? extends K> keyMapper,
        Function<? super T, ? extends U> valueMapper,
        BinaryOperator<U> mergeFunction) {
    Objects.requireNonNull(keyMapper, "keyMapper");
    Objects.requireNonNull(valueMapper, "valueMapper");
    Objects.requireNonNull(mergeFunction, "mergeFunction");
    return collectingAndThen(
            toMap(keyMapper, valueMapper, mergeFunction, HashMap::new),
            map -> (Map<K,U>)Map.ofEntries(map.entrySet().toArray(new Map.Entry[0])));
}*/
//    Collectors 收集器
System.out.println("-----------------------------------------\n");

//    使用ArrayList集合 按照流中元素排列先後順序 進行添加操作
List<String> unmodifiableList = names.stream().collect(Collectors.toUnmodifiableList());
System.out.println(unmodifiableList);
System.out.println("---------------------------------------\n");


//    使用HashSet集合 對流中元素順序 進行添加操作
Set<String> unmodifiableSet = names.stream().collect(Collectors.toUnmodifiableSet());
System.out.println(unmodifiableSet);
System.out.println("---------------------------------------\n");


//    將集合扁平化展開 對其中的字符串的每個字母 進行大寫轉換 使用ArrayList對轉換後的結果進行收集
List<String> strings = snames.stream()
        .collect(Collectors.flatMapping(list -> list.stream().map(String::toUpperCase), Collectors.toList()));
System.out.println(strings);
System.out.println("---------------------------------------\n");


//    對流中元素進行遍歷 對符合預期要求的元素 使用ArrayList集合存放
List<String> filteringPredicate = names.stream().collect(Collectors.filtering("Kirito"::equals,
        Collectors.toList()));
System.out.println(filteringPredicate);
System.out.println("---------------------------------------\n");


//    對流中元素進行遍歷  對key-->keyMapper value-->valueMapper 映射 得到Map集合
Map<Integer, List<Student>> listMap = students.stream()
        .collect(Collectors.toUnmodifiableMap(Student::getId, student -> {
            List<Student> stus = new ArrayList<>();
            stus.add(student);
            return stus;
        }));

System.out.println(listMap);
System.out.println("---------------------------------------\n");


//    對流中元素進行遍歷 對key-->keyMapper-->Key value-->valueMapper-->Value 映射
//    對滿足相同Key的元素 Value進行合併
Map<Integer, String> lengthName = names.stream()
        .collect(Collectors.toUnmodifiableMap(String::length,
                String::toString, (str1, str2) -> str1 + "\t" + str2));
System.out.println(lengthName);
System.out.println("---------------------------------------\n");

三、groupingBy分組

//    三、groupingBy分組

//    分組 groupingBy

//    對T元素按 key進行分組 --> 分組的依據 classifier--> 分組後的集合 value--> 得到 Map<key,value>
/*
Returns a {@code Collector} implementing a "group by" operation on
input elements of type {@code T}, grouping elements according to a
         classification function, and returning the results in a {@code Map}.

<p>The classification function maps elements to some key type {@code K}.
The collector produces a {@code Map<K, List<T>>} whose keys are the
values resulting from applying the classification function to the input
elements, and whose corresponding values are {@code List}s containing the
         input elements which map to the associated key under the classification
function.

<p>There are no guarantees on the type, mutability, serializability, or
thread-safety of the {@code Map} or {@code List} objects returned.*/


/*
      按照key對T進行classifier分組
      使用List集合收集分組結果  單線程 線程安全
public static <T, K> Collector<T, ?, Map<K, List<T>>>
groupingBy(Function<? super T, ? extends K> classifier) {
    return groupingBy(classifier, toList());
}*/


/*
      按照key對T進行classifier分組
      使用自定義收集器downstream 收集分組結果  單線程 線程安全
public static <T, K, A, D>
        Collector<T, ?, Map<K, D>> groupingBy(Function<? super T, ? extends K> classifier,
        Collector<? super T, A, D> downstream) {
    return groupingBy(classifier, HashMap::new, downstream);
}*/


/*
      按照key對T進行classifier分組
      使用自定義mapFactory  重置downstream的CollectorImpl實現
      使用自定義收集器downstream 收集分組結果  單線程 線程安全
public static <T, K, D, A, M extends Map<K, D>>
Collector<T, ?, M> groupingBy(Function<? super T, ? extends K> classifier,
        Supplier<M> mapFactory,
        Collector<? super T, A, D> downstream) {
    Supplier<A> downstreamSupplier = downstream.supplier();
    BiConsumer<A, ? super T> downstreamAccumulator = downstream.accumulator();
    BiConsumer<Map<K, A>, T> accumulator = (m, t) -> {
        K key = Objects.requireNonNull(classifier.apply(t), "element cannot be mapped to a null key");
        A container = m.computeIfAbsent(key, k -> downstreamSupplier.get());
        downstreamAccumulator.accept(container, t);
    };
    BinaryOperator<Map<K, A>> merger = Collectors.<K, A, Map<K, A>>mapMerger(downstream.combiner());
    @SuppressWarnings("unchecked")
    Supplier<Map<K, A>> mangledFactory = (Supplier<Map<K, A>>) mapFactory;
    //    不進行強制類型轉換  重構CollectorImpl實現
    if (downstream.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
        return new CollectorImpl<>(mangledFactory, accumulator, merger, CH_ID);
    }
    else {
        //    進行強制類型轉換  重構CollectorImpl實現
        @SuppressWarnings("unchecked")
        Function<A, A> downstreamFinisher = (Function<A, A>) downstream.finisher();
        Function<Map<K, A>, M> finisher = intermediate -> {
            intermediate.replaceAll((k, v) -> downstreamFinisher.apply(v));
            @SuppressWarnings("unchecked")
            M castResult = (M) intermediate;
            return castResult;
        };
        return new CollectorImpl<>(mangledFactory, accumulator, merger, finisher, CH_NOID);
    }
}*/
//    分組
System.out.println("-----------------------------------------\n");


//    select * from students group by sex ;
Map<String, List<Student>> sexStudent =
        students.stream().collect(Collectors.groupingBy(Student::getSex));
System.out.println(sexStudent);
System.out.println("-----------------------------------------\n");


//    select sex, count(*) from students group by sex ;
Map<String, Long> sexCount =
        students.stream().collect(Collectors.groupingBy(Student::getSex, Collectors.counting()));
System.out.println(sexCount);
System.out.println("-----------------------------------------\n");


//    select sex,avg(salary) from students group by sex ;
Map<String, Double> avgSexSalary = students.stream().collect
        (Collectors.groupingBy(Student::getSex, Collectors.averagingDouble(Student::getSalary)));
System.out.println(avgSexSalary);
System.out.println("-----------------------------------------\n");


//    嵌套分組  先根據sex分組 再對結果按照addr進行分組
Map<String, Map<String, List<Student>>> NestedGroupBy = students.stream()
        .collect(Collectors.groupingBy(Student::getSex, Collectors.groupingBy(Student::getAddr)));
System.out.println(NestedGroupBy);
System.out.println("-----------------------------------------\n");


//    使用自定義收集器downstream 按性別分組  使用HashSet進行 結果收集
Map<String, HashSet<Student>> sexHashSet = students.stream()
        .collect(Collectors.groupingBy(Student::getSex, Collectors.toCollection(HashSet::new)));
System.out.println(sexHashSet);
System.out.println("-----------------------------------------\n");


//    使用自定義收集器downstream 按性別分組  使用HashSet進行 結果收集  重置CollectorImpl實現
Map<String, HashSet<Student>> sexCustomCollectorImpl = students.stream()
        .collect(Collectors.groupingBy(Student::getSex, Hashtable::new, Collectors.toCollection(HashSet::new)));
System.out.println(sexCustomCollectorImpl);
System.out.println("-----------------------------------------\n");

四、groupingByConcurrent分組

 //    四、groupingByConcurrent分組

 //    分組 groupingByConcurrent

 //    流的適用條件:
 //          無序 Collector.Characteristics.UNORDERED
 //          併發 Collector.Characteristics.CONCURRENT
 //    This is a {@link Collector.Characteristics#CONCURRENT concurrent} and
 //    {@link Collector.Characteristics#UNORDERED unordered} Collector.


 /*
       按照key對T進行classifier分組
       使用List集合收集分組結果
 public static <T, K>
         Collector<T, ?, ConcurrentMap<K, List<T>>>
 groupingByConcurrent(Function<? super T, ? extends K> classifier) {
     return groupingByConcurrent(classifier,  ::new, toList());
 }*/


/*
       按照key對T進行classifier分組
       使用自定義收集器downstream 收集分組結果
public static <T, K, A, D>
         Collector<T, ?, ConcurrentMap<K, D>> groupingByConcurrent(Function<? super T, ? extends K> classifier,
         Collector<? super T, A, D> downstream) {
     return groupingByConcurrent(classifier, ConcurrentHashMap::new, downstream);
 }*/


 /*
       按照key對T進行classifier分組
       使用自定義累加器mapFactory  重置downstream的CollectorImpl實現
       使用自定義收集器downstream 收集分組結果
 public static <T, K, A, D, M extends ConcurrentMap<K, D>>
 Collector<T, ?, M> groupingByConcurrent(Function<? super T, ? extends K> classifier,
         Supplier<M> mapFactory,
         Collector<? super T, A, D> downstream) {
     Supplier<A> downstreamSupplier = downstream.supplier();
     BiConsumer<A, ? super T> downstreamAccumulator = downstream.accumulator();
     BinaryOperator<ConcurrentMap<K, A>> merger = Collectors.<K, A, ConcurrentMap<K, A>>mapMerger(downstream.combiner());
     @SuppressWarnings("unchecked")
     Supplier<ConcurrentMap<K, A>> mangledFactory = (Supplier<ConcurrentMap<K, A>>) mapFactory;
     BiConsumer<ConcurrentMap<K, A>, T> accumulator;
     if (downstream.characteristics().contains(Collector.Characteristics.CONCURRENT)) {
         accumulator = (m, t) -> {
             K key = Objects.requireNonNull(classifier.apply(t), "element cannot be mapped to a null key");
             A resultContainer = m.computeIfAbsent(key, k -> downstreamSupplier.get());
             downstreamAccumulator.accept(resultContainer, t);
         };
     }
     else {
         accumulator = (m, t) -> {
             K key = Objects.requireNonNull(classifier.apply(t), "element cannot be mapped to a null key");
             A resultContainer = m.computeIfAbsent(key, k -> downstreamSupplier.get());
             //  多個操作-->同時操作同一個結果容器-->同一時間,有且只有一個進行實際操作-->線程同步
             synchronized (resultContainer) {
                 downstreamAccumulator.accept(resultContainer, t);
             }
         };
     }

     if (downstream.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
         return new CollectorImpl<>(mangledFactory, accumulator, merger, CH_CONCURRENT_ID);
     }
     else {
         @SuppressWarnings("unchecked")
         Function<A, A> downstreamFinisher = (Function<A, A>) downstream.finisher();
         Function<ConcurrentMap<K, A>, M> finisher = intermediate -> {
             intermediate.replaceAll((k, v) -> downstreamFinisher.apply(v));
             @SuppressWarnings("unchecked")
             M castResult = (M) intermediate;
             return castResult;
         };
         return new CollectorImpl<>(mangledFactory, accumulator, merger, finisher, CH_CONCURRENT_NOID);
     }
 }*/
//    分組 無序 併發
System.out.println("-----------------------------------------\n");

//    按性別分組  使用ArrayList進行 結果收集
ConcurrentMap<String, List<Student>> sexStudentConcurrent = students.stream()
        .collect(Collectors.groupingByConcurrent(Student::getSex));
System.out.println(sexStudentConcurrent);
System.out.println("-----------------------------------------\n");


//    使用自定義收集器downstream 按性別分組  使用HashSet進行 結果收集
ConcurrentMap<String, HashSet<Student>> sexHashSetConcurrent = students.stream()
        .collect(Collectors.groupingByConcurrent(Student::getSex, Collectors.toCollection(HashSet::new)));
System.out.println(sexHashSetConcurrent);
System.out.println("-----------------------------------------\n");


//    使用自定義收集器downstream 按性別分組  使用HashSet進行 結果收集  重置CollectorImpl實現
ConcurrentReferenceHashMap<String, HashSet<Student>> sexCustomCollectorImplConcurrent =
        students.stream().collect(Collectors.groupingByConcurrent(Student::getSex,
                ConcurrentReferenceHashMap::new, Collectors.toCollection(HashSet::new)));
System.out.println(sexCustomCollectorImplConcurrent);
System.out.println("-----------------------------------------\n");

五、partitioningBy分區

//    五、partitioningBy分區

//  分區  partitioningBy

/*
      對滿足預期的條件 進行分區 使用ArrayList 進行結果的收集
public static <T>
        Collector<T, ?, Map<Boolean, List<T>>> partitioningBy(Predicate<? super T> predicate) {
    return partitioningBy(predicate, toList());
}*/


/*
      對滿足預期的條件 進行分區 使用自定義收集器downstream 進行結果的收集
public static <T, D, A>
        Collector<T, ?, Map<Boolean, D>> partitioningBy(Predicate<? super T> predicate,
        Collector<? super T, A, D> downstream) {
    BiConsumer<A, ? super T> downstreamAccumulator = downstream.accumulator();
    BiConsumer<Partition<A>, T> accumulator = (result, t) ->
            downstreamAccumulator.accept(predicate.test(t) ? result.forTrue : result.forFalse, t);
    BinaryOperator<A> op = downstream.combiner();
    BinaryOperator<Partition<A>> merger = (left, right) ->
            new Partition<>(op.apply(left.forTrue, right.forTrue),
                    op.apply(left.forFalse, right.forFalse));
    Supplier<Partition<A>> supplier = () ->
            new Partition<>(downstream.supplier().get(),
                    downstream.supplier().get());
    if (downstream.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
        return new CollectorImpl<>(supplier, accumulator, merger, CH_ID);
    }
    else {
        Function<Partition<A>, Map<Boolean, D>> finisher = par ->
                new Partition<>(downstream.finisher().apply(par.forTrue),
                        downstream.finisher().apply(par.forFalse));
        return new CollectorImpl<>(supplier, accumulator, merger, finisher, CH_NOID);
    }
}*/
        //    分區
        System.out.println("-----------------------------------------\n");

        //    select * from students partition by (addr == Sword Art Online) ;
        Map<Boolean, List<Student>> addrPartition = students.stream().collect
                (Collectors.partitioningBy(student -> student.getAddr().equals("Sword Art Online")));
        System.out.println(addrPartition);
        System.out.println("-----------------------------------------\n");


        //    嵌套分區  先根據sex分區 再對結果按照addr進行分區
        Map<Boolean, Map<Boolean, List<Student>>> NestedPartiton = students.stream()
                .collect(Collectors.partitioningBy(student -> student.getSex().equals("Male"),
                        Collectors.partitioningBy(student -> student.getAddr().equals("Sword Art Online"))));
        System.out.println(NestedPartiton);
        System.out.println("-----------------------------------------\n");


        //    使用自定義downstream收集器分區
        Map<Boolean, HashSet<Student>> addrCustomPartition = students.stream().collect(Collectors.partitioningBy
                (student -> student.getAddr().equals("Sword Art Online"), Collectors.toCollection(HashSet::new)));
        System.out.println(addrCustomPartition);
        System.out.println("-----------------------------------------\n");

    }

}

六、測試結果

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.1.2.RELEASE)

2019-02-20 16:58:15.870  INFO 13392 --- [           main] c.j.d.java8.Stream.CollectorsDetail      : Starting CollectorsDetail on DESKTOP-87RMBG4 with PID 13392 (started by 46250 in E:\IdeaProjects\design)
2019-02-20 16:58:15.871  INFO 13392 --- [           main] c.j.d.java8.Stream.CollectorsDetail      : No active profile set, falling back to default profiles: default
2019-02-20 16:58:16.383  INFO 13392 --- [           main] c.j.d.java8.Stream.CollectorsDetail      : Started CollectorsDetail in 0.708 seconds (JVM running for 1.421)
-----------------------------------------

[Kirito, Asuna, Sinon, Yuuki, Alice]
---------------------------------------

[Yuuki, Asuna, Kirito, Sinon, Alice]
---------------------------------------

[KIRITO, ASUNA, SINON, YUUKI, ALICE]
---------------------------------------

[Kirito]
---------------------------------------

{5=[Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], 4=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8)], 3=[Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8)], 2=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)], 1=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
---------------------------------------

{6=Kirito, 5=Asuna    Sinon    Yuuki    Alice}
---------------------------------------

-----------------------------------------

{Female=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

{Female=4, Male=1}
-----------------------------------------

{Female=9.99999999E8, Male=9.99999999E8}
-----------------------------------------

{Female={Alicization=[Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], Sword Art Online=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)], Gun Gale Online=[Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8)], Alfheim Online=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8)]}, Male={Sword Art Online=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}}
-----------------------------------------

{Female=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8), Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)], Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

{Female=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8), Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)], Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

-----------------------------------------

{Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)], Female=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)]}
-----------------------------------------

{Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)], Female=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8), Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

{Female=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8), Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)], Male=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

-----------------------------------------

{false=[Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], true=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8), Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

{false={false=[Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], true=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8)]}, true={false=[], true=[Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}}
-----------------------------------------

{false=[Student(id=4, name=Yuuki, sex=Female, age=15, addr=Alfheim Online, salary=9.99999999E8), Student(id=3, name=Sinon, sex=Female, age=16, addr=Gun Gale Online, salary=9.99999999E8), Student(id=5, name=Alice, sex=Female, age=14, addr=Alicization, salary=9.99999999E8)], true=[Student(id=2, name=Asuna, sex=Female, age=17, addr=Sword Art Online, salary=9.99999999E8), Student(id=1, name=Kirito, sex=Male, age=18, addr=Sword Art Online, salary=9.99999999E8)]}
-----------------------------------------

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