collection framework java

Student

public class Student {
    private String firstName;
    private String lastName;
    private String id;
    private double avgGrade;
    public Student(String firstName, String lastName, String id, double avgGrade) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.id = id;
        this.avgGrade = avgGrade;
    }
    public String getFirstName() {
        return firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public String getId() {
        return id;
    }
    public double getAvgGrade() {
        return avgGrade;
    }
    @Override
    public String toString() {
        return "Student{" +
                "firstName='" + firstName + '\'' +
                ", lastName='" + lastName + '\'' +
                ", id='" + id + '\'' +
                ", avgGrade=" + avgGrade +
                '}';
    }
}

Faculty

import java.util.List;
public class Faculty {
    private String name;
    private List<Student> studentList;
    public Faculty(String name, List<Student> studentList) {
        this.name = name;
        this.studentList = studentList;
    }
    public String getName() {
        return name;
    }
    public List<Student> getStudentList() {
        return studentList;
    }
}

Institute

import java.util.List;
public class Institute {
    private String name;
    private List<Faculty> facultyList;
    public Institute(String name, List<Faculty> facultyList) {
        this.name = name;
        this.facultyList = facultyList;
    }
    public String getName() {
        return name;
    }
    public List<Faculty> getFacultyList() {
        return facultyList;
    }
}

Main

import java.util.*;
import java.util.stream.Collectors;
public class Main {
    public static void main(String[] args) {
        Institute institute = new Institute("Oxford", new ArrayList<Faculty>() {
            {
                add(new Faculty("Math", new LinkedList<Student>() {
                    {
                        add(new Student("White", "John", "WJ0123", 66.89));
                        add(new Student("Black", "Mike", "BM4567", 36.93));
                        add(new Student("Jackson", "Stue", "JS8475", 98.54));
                    }
                }));
                add(new Faculty("ComputerScience", new LinkedList<Student>() {
                    {
                        add(new Student("Starr", "George", "GS8974", 97.25));
                        add(new Student("Arnold", "Rock", "AR2354", 85.65));
                    }
                }));
            }
        });
        long studentCount = institute.getFacultyList().stream()
                .mapToLong(faculty -> faculty.getStudentList().size())
                .sum();
        System.out.println("studentCount = " + studentCount);
        Optional<Faculty> facultyMaxStudents = institute.getFacultyList().stream()
                .max(Comparator.comparingInt(faculty -> faculty.getStudentList().size()));
        facultyMaxStudents.ifPresent(faculty -> System.out.println(faculty.getName()));
        List<Student> studentList = institute.getFacultyList().stream()
                .flatMap(faculty -> faculty.getStudentList().stream())
                .filter(student -> student.getAvgGrade() >= 95 && student.getAvgGrade() <= 100)
                .collect(Collectors.toList());
        System.out.println("studentList = " + studentList);
    }
}

Enjoy %)