Intermediate Methods of Stream in Java

// Java Program to illustrate Intermediate Methods of Streams 
// Case 1: filter(predicate) Method 
 
// Importing input output classes
import java.io.*;
// Importing List Class from java.util package  
import java.util.List;

// Main Class 
public class GFG {
  
    // Main driver method 
    public static void main (String[] args) {
      
      // Creating an object of List Class by 
      // declaring a list of Integers
      
      // Custom entries in the list elements 
      List<Integer> intList = List.of(15,20,48,63,49,27,56,32,9);
      
      // Calling the function to 
      // print the list of Even numbers
      printEvenNumber(intList);
    }
  
  // Method 2
  // Helper method 
  // To print the even numbers using filter method. 
  private static void printEvenNumber(List<Integer> intList){
    
        // Display message 
        System.out.print("\nEven numbers are : ");
        
        // Illustrating filter method usage  
        intList.stream().filter(
          element -> (element%2==0)
        )
        .forEach(
          element -> System.out.print(element+ " ")
        );
        
    }
}

// Java Program to illustrate Intermediate Method of Stream
// Case 2: sorted() Method 

// Importing input output class
import java.io.*;
// Importing List class from java.util package
import java.util.List;

// Main class
class GFG {

    // Method 1
    // To print the elements of the Sorted List
    public static void
    printSortedList(List<Integer> intList)
    {

        // Sorts and returns the stream to the forEach
        // illustrating stream method
        intList.stream().sorted().forEach(
            element -> System.out.println(element));
    }

    // Method 2
    // Main driver method
    public static void main(String[] args)
    {

        // Creating an object of List class
        // Declaring object of Integer type

        // Custom entries
        List<Integer> intList
            = List.of(68, 45, 99, 21, 8, 76, 34, 19);

        // Display message only
        System.out.println(
            "Elements of Sorted List are as follows : ");

        // Calling the method to print the Sorted List
        printSortedList(intList);
    }
}

// Java Program to illustrate Intermediate Method of Stream
// Case 3: distinct() Method 

// Importing input output classes
import java.io.*;
// Importing List class from java.util package
import java.util.List;

// Main Class
class GFG {

    // Method 1
    // To find distinct elements from the List
    public static void
    findDistinctElements(List<Integer> intList)
    {
        intList.stream().distinct().forEach(
            element -> System.out.print(element + " "));

        // Display message only
        System.out.println("\n\nSorted List is ");

        // Also we are sorting elements at the same time
        intList.stream().distinct().sorted().forEach(
            element -> System.out.print(element + " "));
    }

    // Method 2
    // Main driver method
    public static void main(String[] args)
    {

        // Creating an object of List class
        // Declaring object of Integer type

        // Custom integer inputs
        List<Integer> intList
            = List.of(12, 54, 63, 12, 7, 98, 63, 54, 72);

        // Calling the Method 1 as above created to
        // find the distinct elements from the list
        findDistinctElements(intList);
    }
}

// Java Program to illustrate Intermediate Stream Methods
// Case 4: map() Method 

// Importing input output class
import java.io.*;
// Importing List class from the java.util package
import java.util.List;

// Main Class
class GFG {

    // Method 1
    // To find the cube of elements in the List
    public static void findTheCube(List<Integer> intList)
    {

        intList.stream()
            .map(element -> element * element * element)
            .forEach(
                element -> System.out.print(element + " "));

        // Display message only
        System.out.println(
            "\n\nOutput after distinct() implementation : ");

        // Applying distinct() on this
        intList.stream()
            .distinct()
            .map(element -> element * element * element)
            .forEach(
                element -> System.out.print(element + " "));

        // Display message only
        System.out.println(
            "\n\nOutput after sorted() implementation : ");

        // Now applying sorted() on this
        intList.stream()
            .distinct()
            .sorted()
            .map(element -> element * element * element)
            .forEach(
                element -> System.out.print(element + " "));

        // Display message only
        System.out.println(
            "\n\nOutput after filter() implementation : ");

        // Applying Filter() that values
        // only below 10000 will be printed
        intList.stream()
            .distinct()
            .sorted()
            .map(element -> element * element * element)
            .filter(element -> element < 10000)
            .forEach(
                element -> System.out.print(element + " "));
    }

    // Method 2
    // Main driver method
    public static void main(String[] args)
    {

        // Creating an object of List class and
        // declaring object of Integer type

        // Custom entries
        List<Integer> intList
            = List.of(5, 19, 8, 23, 6, 54, 32, 5, 23);

        // Calling the Method1 in the main() body
        // to get the cube of the elements in the List
        findTheCube(intList);
    }
}