int id;

String tagName;

int count;

Nodes(int id, String tagName, int count) {

this.id = id;

this.tagName = tagName;

this.count = count;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getTagName() {

return tagName;

}

public void setTagName(String tagName) {

this.tagName = tagName;

}

public int getCount() {

return count;

}

public void setCount(int count) {

this.count = count;

}

private int id;

private String name;

private int age;

private long salary;

public Employee(int id, String name, int age, long salary) {

super();

this.id = id;

this.name = name;

this.age = age;

this.salary = salary;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public long getSalary() {

return salary;

}

public void setSalary(long salary) {

this.salary = salary;

}

@Override

public String toString() {

return "Employee [id=" + id + ", name=" + name + ", age=" + age + ", salary=" + salary + "]";

}

int id;

String name;

Person1(int id, String name) {

this.id = id;

this.name = name;

}

public int getId() {

return id;

}

public void setId(int id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public static void main(String[] args) {

// input

int[] arr = new int[] { 9, 10, 15, 8, 49, 25, 98, 32, 10 };

List<Integer> list = Arrays.asList(11, 10, 15, 8, 49, 25, 98, 32, 10);

// 1. to filter even nos from list

/*

// Arrays.stream(arr).filter(i ->i %2 == 0).forEach(System.out::println);

// 2.Given a list of integers, find out all the numbers starting with 1 using

// Stream functions

/*

// 3 .How to find duplicate elements in a given integers list in java using

// Stream functions

/*

// 4 .Given the list of integers, find the first element of the list using

// Stream functions

/*

// 5 .Given a list of integers, find the total number of elements present in the

// list using Stream functions

/*

// 6.find the maximum value element present in it using Stream functions

/*

// 7. find the first non-repeated character in it using Stream functions

// input.chars().mapToObj().collect(,,).entrySet().filter().map().getFirst().get()

String input = "Java articles are Awesome";

Character ch = input.chars().mapToObj(s -> Character.toLowerCase(Character.valueOf((char) s)))

.collect(Collectors.groupingBy(Function.identity(), LinkedHashMap::new, Collectors.counting()))

.entrySet()

.stream().filter(entry -> entry.getValue() == 1).map(entry -> entry.getKey()).findFirst().get();

System.out.println("first character non repeating::" + ch);

// 8.Given a String, find the first repeated character in it using Stream

// functions

/*

/*

// 9. a list of integers, sort all the values present in it using Stream

// functions

/*

// 10.Given a list of integers, sort all the values present in it in descending

// order using Stream functions

// list.stream().sorted(Collections.reverseOrder()).forEach(System.out::println);

// Arrays.stream(arr).boxed().sorted(Collections.reverseOrder()).forEach(System.out::println);

// 11.Given an integer array nums, return true if any value appears at least

// twice in the array,

// and return false if every element is distinct

List<Integer> numList = Arrays.stream(arr).boxed().collect(Collectors.toList());

Set<Integer> set = new HashSet<>(numList);

boolean res = false;

if (numList.size() == set.size()) {

res = false;

} else {

res = true;

}

System.out.println("value appearing twice::" + res);

// 12. How will you get the current date and time using Java 8 Date and Time API

System.out.println("Current Local Date: " + java.time.LocalDate.now());

// Used LocalDate API to get the date

System.out.println("Current Local Time: " + java.time.LocalTime.now());

// Used LocalTime API to get the time

System.out.println("Current Local Date and Time: " + java.time.LocalDateTime.now());

// Used LocalDateTime API to get both date and time

// 13. Write a Java 8 program to concatenate two Streams?

List<String> list1 = Arrays.asList("Java", "8");

List<String> list2 = Arrays.asList("explained", "through", "programs");

Stream<String> concatStream = Stream.concat(list1.stream(), list2.stream());

// Concatenated the list1 and list2 by converting them into Stream

concatStream.forEach(k -> {

System.out.print(k + " ");

});

// 14. Java 8 program to perform cube on list elements and filter numbers

// greater than 50

// list.stream().map(i-> i*i*i).filter(i

// ->i>50).collect(Collectors.toList()).forEach(System.out::println);

// Arrays.stream(arr).map(i-> i*i*i).filter(i

// ->i>50).boxed().collect(Collectors.toList()).forEach(System.out::println);

// 15. Write a Java 8 program to sort an array and then convert the sorted array

// into Stream

Arrays.parallelSort(arr);

Arrays.stream(arr).forEach(System.out::println);

// 16 . How to use map to convert object into Uppercase in Java 8

List<String> names = Arrays.asList(new String[] { "Aa", "Bb", "Cc", "Dd", "Aa" });

System.out.println(names.stream().map(String::toLowerCase).collect(Collectors.toList()));

// 17. How to convert a List of objects into a Map by considering duplicated

// keys and store them in sorted order?

Map<String, Long> map = names.stream()

.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

System.out.println(map);

// 18. How to find only duplicate elements with its count from the String

// ArrayList in Java8

Map<String, Long> mapDuplicate = names.stream().filter(x -> Collections.frequency(names, x) > 1)

.collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

System.out.println("dup" + mapDuplicate);

// 19. How to check if list is empty in Java 8 using Optional, if not null

// iterate through the list and print the object?

Nodes node1 = new Nodes(1, "vee", 1);

Nodes node2 = new Nodes(2, "viv", 2);

List<Nodes> nodesList = new ArrayList<>();

nodesList.add(node1);

nodesList.add(node2);

Optional.ofNullable(nodesList).orElseGet(Collections::emptyList).stream().filter(Objects::nonNull)

.map(Nodes::getTagName).forEach(s -> System.out.println("tag names is:" + s));

// 20. Program to find the Maximum element in an array

System.out.println(list.stream().max(Integer::compare).get());

System.out.println(Arrays.stream(arr).max().getAsInt());

// 21. program to print the count of each character in a String?

String s = "string data to count each character";

Map<String, Long> countMap = Arrays.stream(s.split("")).map(String::toLowerCase)

.collect(Collectors.groupingBy(str -> str, LinkedHashMap::new, Collectors.counting()));

System.out.println(countMap);

// 21. sort employee by salary in ascending order

List<Employee> employees = new ArrayList<Employee>();

employees.add(new Employee(10, "Ramesh", 30, 400000));

employees.add(new Employee(20, "John", 29, 350000));

employees.add(new Employee(30, "Tom", 30, 450000));

employees.add(new Employee(40, "Pramod", 29, 500000));

employees.add(new Employee(50, "Pramodini", 31, 500000));

List<Employee> resultAsc = employees.stream().sorted(((o1, o2) -> (int) (o1.getSalary() - o2.getSalary())))

.collect(Collectors.toList());

System.out.println("Ascending order::" + resultAsc);

System.out.println(

employees.stream().sorted(Comparator.comparingLong(Employee::getSalary)).collect(Collectors.toList()));

List<Employee> resultDesc = employees.stream().sorted(((o1, o2) -> (int) (o2.getSalary() - o1.getSalary())))

.collect(Collectors.toList());

System.out.println("Descending order::" + resultDesc);

System.out.println(employees.stream().sorted(Comparator.comparingLong(Employee::getSalary).reversed())

.collect(Collectors.toList()));

// second Highest Salary

// System.out.println("Second Highest salary::");

// employees.stream().collect(Collectors.groupingBy(Employee::getSalary)).entrySet();

// 22. odd even sum

int[] arr1 = new int[] { 1, 2, 4, 6, 7 };

System.out.println(Arrays.stream(arr1).boxed().filter(v -> v % 2 == 0)

.collect(Collectors.summingInt(Integer::intValue)));

System.out.println(Arrays.stream(arr1).boxed()

.filter(v -> v % 2 == 0).mapToInt(Integer::intValue).sum());

// sum of odd and even 8 12

System.out.println(Arrays.stream(arr1).mapToObj(ob -> Integer.valueOf(ob))

.collect(Collectors.groupingBy(t -> t % 2 == 0 ? "ODD" : "EVEN")));

Map<String, Integer> map1 = Arrays.stream(arr1).boxed().collect(Collectors

.groupingBy(e -> e % 2 == 0 ? "OddSum" : "EvenSum", Collectors.summingInt(Integer::intValue)));

System.out.println("map::" + map1);

// 23. FindDuplicatesUsingStreamDistinctMethod

String[] companies = new String[] {

"Meta", "Apple", "Amazon", "Netflix", "Meta", "Google", "Apple" // duplicate

};

System.out.println("1. Original String[] Array with duplicates : \n");

Arrays.stream(companies).forEach(System.out::println);

// 24. convert list to map

List<Person1> listPerson = new ArrayList<>();

listPerson.add(new Person1(1, "vna"));

listPerson.add(new Person1(2, "vid"));

Map<Integer, Person1> mapPerson = listPerson.stream()

.collect(Collectors.toMap(Person1::getId, Function.identity()));

System.out.println(mapPerson);

// 25.Find word count of the words in string

// o/p this -1, is-2 ,word-2,count-1,for-1

String str = "this is word count for word is good";

Map<String, Long> mapStr = Arrays.stream(str.split(" "))

.filter(x -> Collections.frequency(Arrays.asList(str.split(" ")), x) >= 1)

.collect(Collectors.groupingBy(Function.identity(), LinkedHashMap::new, Collectors.counting()));

System.out.println(mapStr);

// o/p is-2 ,word-2,this -1,count-1,for-1

Arrays.stream(str.split(" "))

.filter(x -> Collections.frequency(Arrays.asList(str.split(" ")), x) >= 1)

.collect(Collectors.groupingBy(Function.identity(), LinkedHashMap::new, Collectors.counting()))

.entrySet().stream()

.sorted(Map.Entry.<String, Long>comparingByValue().reversed()

.thenComparing(Map.Entry.comparingByKey()))

.forEach(System.out::println);

}