import java.util.*;
import java.lang.*;

public class StudentMap {

  private Map<Integer,Student> students;
  
  public StudentMap() {
    students = new LinkedHashMap<Integer,Student>();
    populateMap();
  }
  
  public final void populateMap() {
    students.put(1, new Student("John", "Smith"));
    students.put(2, new Student("Stanley", "Peters"));
    students.put(3, new Student("Edgar", "Bloch"));
    students.put(4, new Student("Suzan", "Miles"));
    students.put(5, new Student("Mary", "Poppins"));
  }
  
  public void iterateMapEntries() { 
    Set set = students.entrySet();
    Iterator it = set.iterator();
    while(it.hasNext()) {
      System.out.println(it.next().toString());
    }
  }
  
  public void iterateMapValues() { 
    Collection col = students.values();
    Iterator it = col.iterator();
    while(it.hasNext()) {
      System.out.println(it.next().toString());
    }
  }
  
  public void iterateMapKeys() { 
    Set set = students.keySet();
    Iterator it = set.iterator();
    while(it.hasNext()) {
      System.out.println(it.next().toString());
    }
  }
  
  public static void main(String args[]) {
    StudentMap stl = new StudentMap();
    System.out.println("Map keys are:");
    stl.iterateMapKeys();
    System.out.println("Map values are:");
    stl.iterateMapValues();
    System.out.println("Map key-value pairs are:");
    stl.iterateMapEntries();
  }
}