Sorting Program Using Stream API and sorted() method in java Stream Interface

Sorting Using Stream API sorted() method in java : copy below code and study , to understand different sorting techniques using java Stream API : 

I know , this program is very big , but its enough to practice whole sorting using Stream API in java  ,due to time limitation , i am skipping theory part we will see theory in depth in upcoming articles , till that time use this program and try to understand sorting using stream in java : 

Step 1: write Student class as below :

package com.crtr4u.www;
public class Student {
	int id;
	String name;
	String department;
	public Student() {
		super();
	}
	public Student(int id, String name, String department) {
		super();
		this.id = id;
		this.name = name;
		this.department = department;
	}
	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 String getDepartment() {
		return department;
	}
	public void setDepartment(String department) {
		this.department = department;
	}
	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", department=" + department + "]";
	}
}

Step 2: Write main class as below :

package com.crtr4u.www;

import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collectors;

public class SortingDemo {
	public static void main(String[] args) {
		List<Integer> numList=Arrays.asList(1,4,2,6,5,3);
		
		System.out.println("original numerical list : "+numList);
		System.out.println("Sorted numbers : ");
		numList.stream().sorted().forEach(System.out::print);
		
		System.out.println("\nReversed numbers :");
		numList.stream().sorted(Comparator.reverseOrder()).forEach(System.out::print);
		
		
		List<String> stringList=Arrays.asList("A","D","C","B","Z","W");
		
		System.out.println("\noriginal String list : "+stringList);
		System.out.println("Sorted String  : ");
		stringList.stream().sorted().forEach(System.out::print);
		
		System.out.println("\nReversed String  :");
		stringList.stream().sorted(Comparator.reverseOrder()).forEach(System.out::print);

		List<Student> studentList = Arrays.asList(new Student(1, "A", "MCA"), new Student(4, "B", "Accounting"),
				new Student(3, "C", "Mechanical"), new Student(2, "D", "MCA"), new Student(6, "a", "Pharmacy"),
				new Student(5, "d", "Chemical"), new Student(7, "E", "accounting"));
		System.out.println("\nStudent list ");
		
		for (Student s : studentList) {
			System.out.println(s);
		}

		List<Student> sortedListByName1 = studentList.stream().sorted((s1, s2) -> s1.getName().compareTo(s2.getName()))
				.collect(Collectors.toList());
		System.out.println("Sorted by name  : ");
		for (Student s : sortedListByName1) {
			System.out.println(s);
		}

		List<Student> sortedListById1 = studentList.stream().sorted((s1, s2) -> {
			if (s1.getId() == s2.getId()) {
				return 0;
			} else if (s1.getId() > s2.getId()) {
				return 1;
			} else {
				return -1;
			}
		}).collect(Collectors.toList());
		System.out.println("Sorted by id : ");

		for (Student s : sortedListById1) {
			System.out.println(s);
		}

		List<Student> sortedListByName2 = studentList.stream().sorted(Comparator.comparing(Student::getName))
				.collect(Collectors.toList());
		System.out.println("Sorted by name :");
		for (Student s : sortedListByName2) {
			System.out.println(s);
		}
		List<Student> sortedListByName3 = studentList.stream().sorted(Comparator.comparing(Student::getName).reversed())
				.collect(Collectors.toList());
		System.out.println("Sorted by name reversed :");
		for (Student s : sortedListByName3) {
			System.out.println(s);
		}

		List<Student> sortedById2 = studentList.stream().sorted(Comparator.comparingInt(Student::getId))
				.collect(Collectors.toList());

		System.out.println("Sorted by id : ");

		for (Student s : sortedById2) {
			System.out.println(s);
		}

		List<Student> sortedById3 = studentList.stream().sorted(Comparator.comparingInt(Student::getId).reversed())
				.collect(Collectors.toList());

		System.out.println("Sorted by id reversed: ");

		for (Student s : sortedById3) {
			System.out.println(s);
		}
	}
}

Output :

original numerical list : [1, 4, 2, 6, 5, 3]
Sorted numbers : 
123456
Reversed numbers :
654321
original String list : [A, D, C, B, Z, W]
Sorted String  : 
ABCDWZ
Reversed String  :
ZWDCBA
Student list 
Student [id=1, name=A, department=MCA]
Student [id=4, name=B, department=Accounting]
Student [id=3, name=C, department=Mechanical]
Student [id=2, name=D, department=MCA]
Student [id=6, name=a, department=Pharmacy]
Student [id=5, name=d, department=Chemical]
Student [id=7, name=E, department=accounting]
Sorted by name  : 
Student [id=1, name=A, department=MCA]
Student [id=4, name=B, department=Accounting]
Student [id=3, name=C, department=Mechanical]
Student [id=2, name=D, department=MCA]
Student [id=7, name=E, department=accounting]
Student [id=6, name=a, department=Pharmacy]
Student [id=5, name=d, department=Chemical]
Sorted by id : 
Student [id=1, name=A, department=MCA]
Student [id=2, name=D, department=MCA]
Student [id=3, name=C, department=Mechanical]
Student [id=4, name=B, department=Accounting]
Student [id=5, name=d, department=Chemical]
Student [id=6, name=a, department=Pharmacy]
Student [id=7, name=E, department=accounting]
Sorted by name :
Student [id=1, name=A, department=MCA]
Student [id=4, name=B, department=Accounting]
Student [id=3, name=C, department=Mechanical]
Student [id=2, name=D, department=MCA]
Student [id=7, name=E, department=accounting]
Student [id=6, name=a, department=Pharmacy]
Student [id=5, name=d, department=Chemical]
Sorted by name reversed :
Student [id=5, name=d, department=Chemical]
Student [id=6, name=a, department=Pharmacy]
Student [id=7, name=E, department=accounting]
Student [id=2, name=D, department=MCA]
Student [id=3, name=C, department=Mechanical]
Student [id=4, name=B, department=Accounting]
Student [id=1, name=A, department=MCA]
Sorted by id : 
Student [id=1, name=A, department=MCA]
Student [id=2, name=D, department=MCA]
Student [id=3, name=C, department=Mechanical]
Student [id=4, name=B, department=Accounting]
Student [id=5, name=d, department=Chemical]
Student [id=6, name=a, department=Pharmacy]
Student [id=7, name=E, department=accounting]
Sorted by id reversed: 
Student [id=7, name=E, department=accounting]
Student [id=6, name=a, department=Pharmacy]
Student [id=5, name=d, department=Chemical]
Student [id=4, name=B, department=Accounting]
Student [id=3, name=C, department=Mechanical]
Student [id=2, name=D, department=MCA]
Student [id=1, name=A, department=MCA]

Happy Learning , Practice above program and feel free to ask any questions. Great Day Ahead..