Utilizing Comparator in Java 8 for Efficient Object Sorting

In Java programming, the Comparator interface plays a crucial role in sorting objects based on custom criteria. Java 8 introduced a streamlined approach to defining comparators using the Comparator.comparing method, enhancing code readability and maintainability.

Consider the following code example, which demonstrates the application of Comparator in Java 8 to sort a collection of Student objects based on their grades:

javaCopy codeimport java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

public class StudentExample {

    public static void main(String[] args) {
        List<Student> studentList = new ArrayList<>();

        // Adding sample student records to the list
        studentList.add(new Student("Sachin", "English", 80.45));
        studentList.add(new Student("Raj", "Science", 70.12));
        studentList.add(new Student("Vikram", "Mathematics", 66.54));

        // Sorting the studentList based on grades in descending order,
        // then by name, and finally by subject
        studentList.sort(Comparator.comparing(Student::getGrade)
                .reversed()
                .thenComparing(Student::getName)
                .thenComparing(Student::getSubject));

        // Printing the sorted studentList
        System.out.println(studentList);
    }
}

In this code snippet, the Student class represents a typical entity with attributes such as name, subject, and grade. The Comparator.comparing method is utilized to create a comparator that compares Student objects based on their grades. Additionally, the reversed() method is invoked to ensure descending order sorting.

Furthermore, the thenComparing method is employed to handle cases where multiple students have the same grade. It enables secondary sorting based on the student's name and then their subject, ensuring a comprehensive and deterministic sorting order.

By leveraging the Comparator functionality in Java 8, software engineers can efficiently manage object sorting requirements with concise and expressive code, thereby enhancing code quality and developer productivity.