Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        Map<String, Student> map = new HashMap<>();
        map.put("s1", new Student(5, "A"));
        map.put("s2", new Student(4, "B"));
        map.put("s3", new Student(10, "C"));
        map.put("s4", new Student(2, "D"));
        Collection<Student> students = map.values();
        List<Student> list = new ArrayList<>(students);
        Collections.sort(list, new MyComparator());

        for (Iterator<Student> it = list.iterator(); it.hasNext();) {
            Student stdn = (Student) it.next();
            System.out.println("Student id : " + stdn.id);
            System.out.println("Student Name : " + stdn.name);
        }
    }
}

class MyComparator implements Comparator<Student> {

    @Override
    public int compare(Student s1, Student s2) {
        return s1.name.compareTo(s2.name);
    }
}

class Student {
    int id;
    String name;

    Student(int id, String name) {
        this.id = id;
        this.name = name;
    }
}