public class Person implements Comparable<Person> {

   // Constructor

   public Person(String firstName, String surname) {

     this.firstName = firstName;

     this.surname = surname;

   }

   @Override

   public String toString() {

     return firstName + " " + surname;

   }

   // Compare Person objects

   public int compareTo(Person person) {

     int result = surname.compareTo(person.surname);

     return result == 0 ? firstName.compareTo(person.firstName) : result;

   }

   private String firstName;            // First name of person

   private String surname;              // Second name of person

 }

 import java.util.Vector;

 import java.util.ListIterator;

 import java.util.Collections;

 import java.io.*;

 public class TryVector {

   public static void main(String[] args) {

     Person aPerson = null;                                             // A person object

     Vector<Person> filmCast = new Vector<>();

     // Populate the film cast

     while(true) {                                                      // Indefinite loop

       aPerson = readPerson();                                          // Read in a film star

       if(aPerson == null) {                                            // If null obtained...

         break;                                                         // We are done...

       }

       filmCast.add(aPerson);                                           // Otherwise, add to the cast

     }

     int count = filmCast.size();

     System.out.println("You added " + count + (count == 1 ? " person":  " people") + " to the cast:");

     // Show who is in the cast using an iterator

     ListIterator<Person> thisLot = filmCast.listIterator();

     while(thisLot.hasNext()) {       // Output all elements

       System.out.println( thisLot.next());

     }

     System.out.println("\nThe vector currently has room for " + (filmCast.capacity() - count) + " more people.");

     // Now sort the vector contents and list it

     Collections.sort(filmCast);

     System.out.println("\nThe cast in ascending sequence is:");

     for(Person person : filmCast) {

       System.out.println(person);

     }

   }

   // Read a person from the keyboard

   static Person readPerson() {

     // Read in the first name and remove blanks front and back

     String firstName = null;

     String surname = null;

     System.out.println("\nEnter first name or ! to end:");

     try {

       firstName = keyboard.readLine().trim();                          // Read and trim a string

       if(firstName.charAt(0) == '!') {                                 // Check for ! entered

         return null;                                                   // If so, we are done...

       }

       // Read in the surname, also trimming blanks

       System.out.println("Enter surname:");

       surname = keyboard.readLine().trim();                            // Read and trim a string

     } catch(IOException e) {

       System.err.println("Error reading a name.");

       e.printStackTrace();

       System.exit(1);

     }

     return new Person(firstName,surname);

   }

   static BufferedReader keyboard = new BufferedReader(new InputStreamReader(System.in));

 }