import java.io.*;

public class SerialTest{
  PrintWriter pw = new PrintWriter(System.out, true);  

  public static void main(String[] args) {
    Phone phone01 = Phone.getNewPhone("John Doe", "555-1212");
    Phone phone02 = Phone.getBlankPhone();
    
    phone01.printNumber(); // Print start value
    
    try {
      ObjectOutputStream out = new ObjectOutputStream( new FileOutputStream("object.dat"));
      out.writeObject(phone01); // Serialize Object
      out.close();
    } catch(Exception e){
      e.printStackTrace();
    }

    phone01.setNumber("111-1111"); // Change Object 
    
    try {
      ObjectInputStream in = new ObjectInputStream( new FileInputStream("object.dat"));
      phone02 = (Phone) in.readObject();
      in.close();
    } catch(Exception e){
      e.printStackTrace();
    }
    
    phone01.printNumber(); // Print Changed Object
    phone02.printNumber(); // Print Original Object
    
  }
}

class Phone implements Serializable {
  private String name;
  private String number;

  private Phone(){
    this.name = "";
    this.number = "";
  }
 
  private Phone(String name, String number){
    this.name = name;
    this.number = number;
  }

  public static Phone getNewPhone(String name, String number){
    Phone newPhone = new Phone(name, number);
    return newPhone;
  }

  public static Phone getBlankPhone(){
    Phone newPhone = new Phone();
    return newPhone;
  }

  public void setNumber(String number){
    this.number = number;  
  }

  public void printNumber(){
    System.out.println("Phone Entry: " + this.name + " - " + this.number);    
  }

}