3.2

package opgave3_2;

import java.util.Set;
import java.util.TreeSet;

public class Skole {
	private String navn;
	private static Set<Student> students = new TreeSet<>();

	public Skole(String navn) {
		this.navn = navn;
	}

	public String getNavn() {
		return navn;
	}

	public void setNavn(String navn) {
		this.navn = navn;
	}

	public Set<Student> getStudent() {
		return new TreeSet<>(students);
	}

	public static void addStudent(Student student) {
		if (!students.contains(student)) {
			students.add(student);
		}
	}

	public static void removeStudent(Student student) {
		if (students.contains(student)) {
			students.remove(student);
		}
	}

	public double gennemsnit() {
		int sum = 0;
		int counter = 0;
		double average = 0;
		for (Student s : students) {
			for (Integer k : Student.getKarakter()) {
				sum += k;
				counter++;
			}
		}
		average = sum / counter;
		return average;
	}

	public Student findStuderende(int studieNr) {
		Student student = null;
		for (Student s : students) {
			if (s.getStudieNr() == studieNr) {
				student = s;
			}
		}
		return student;
	}

	public String toString() {
		return "" + navn;
	}
}


-----

package opgave3_2;

import java.util.Set;
import java.util.TreeSet;

public class Student implements Comparable<Student> {
	private String navn;
	private int studieNr;
	private static Set<Integer> karakterer = new TreeSet<>();

	public Student(String navn, int studieNr) {
		this.navn = navn;
		this.studieNr = studieNr;
	}

	public String getNavn() {
		return navn;
	}

	public int getStudieNr() {
		return studieNr;
	}

	public static Set<Integer> getKarakter() {
		return new TreeSet<>(karakterer);
	}

	public void setNavn(String navn) {
		this.navn = navn;
	}

	public void addKarakter(int karakter) {
		Student.karakterer.add(karakter);
	}

	public String toString() {
		return "" + navn + ", " + studieNr;
	}

	@Override
	public int compareTo(Student o) {
		if (studieNr == o.studieNr) {
			return 0;
		} else if (studieNr > o.studieNr) {
			return 1;
		} else {
			return -1;
		}
	}
}


-----

package opgave3_2;

import java.util.Comparator;

public class StudentComparator implements Comparator<Student> {

	@Override
	public int compare(Student o1, Student o2) {
		if (o1.getNavn() == o2.getNavn()) {
			return 0;
		} else {
			return -1;
		}
	}
}