Making a Class Cloneable - Java Object Oriented Design

Introduction

Implement the Cloneable interface; then call that object's clone method to make a copy of it.
Demo Code

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;

public class Main {

  public static void main(String[] args) {
    Team team1 = new Team();
    Team team2 = new Team();

    team1.setCity("Boston");
    team1.setName("Flag");

    team2.setCity("Chicago");
    team2.setName("Fire");

    Team team3 = team1;/*from w  w  w.  j a va  2s  .  c om*/
    Team team4 = team2.clone();

    Team team5 = team1.shallowCopyClone();

    System.out.println("Team 3:");
    System.out.println(team3.getCity());
    System.out.println(team3.getName());

    System.out.println("Team 4:");
    System.out.println(team4.getCity());
    System.out.println(team4.getName());

    // Teams move to different cities
    team1.setCity("St. Louis");
    team2.setCity("Orlando");

    System.out.println("Team 3:");
    System.out.println(team3.getCity());
    System.out.println(team3.getName());

    System.out.println("Team 4:");
    System.out.println(team4.getCity());
    System.out.println(team4.getName());

    System.out.println("Team 5:");
    System.out.println(team5.getCity());
    System.out.println(team5.getName());

    if (team1 == team3) {
      System.out.println("team1 and team3 are equal");
    } else {
      System.out.println("team1 and team3 are NOT equal");
    }

    if (team1 == team5) {
      System.out.println("team1 and team5 are equal");
    } else {
      System.out.println("team1 and team5 are NOT equal");
    }

  }

}

class Team implements Cloneable, Serializable {

  private String name;
  private String city;

  /**
   * @return the name
   */
  public String getName() {
    return name;
  }

  /**
   * @param name
   *          the name to set
   */
  public void setName(String name) {
    this.name = name;
  }

  /**
   * @return the city
   */
  public String getCity() {
    return city;
  }

  /**
   * @param city
   *          the city to set
   */
  public void setCity(String city) {
    this.city = city;
  }

  public String getFullName() {
    return this.name + " - " + this.city;
  }

  /**
   * Overrides Object's clone method to create a deep copy
   * 
   * @return
   */
  @Override
  public Team clone() {

    Team obj = null;
    try {
      ByteArrayOutputStream baos = new ByteArrayOutputStream();
      ObjectOutputStream oos = new ObjectOutputStream(baos);
      oos.writeObject(this);
      oos.close();

      ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
      ObjectInputStream ois = new ObjectInputStream(bais);
      obj = (Team) ois.readObject();
      ois.close();
    } catch (IOException e) {
      e.printStackTrace();
    } catch (ClassNotFoundException cnfe) {
      cnfe.printStackTrace();
    }
    return obj;
  }

  /**
   * Overrides Object's clone method to create a shallow copy
   * 
   * @return
   */
  public Team shallowCopyClone() {

    try {
      return (Team) super.clone();
    } catch (CloneNotSupportedException ex) {
      return null;
    }
  }

  @Override
  public boolean equals(Object obj) {

    if (this == obj) {
      return true;
    }
    if (obj instanceof Team) {
      Team other = (Team) obj;
      return other.getName().equals(this.getName())
          && other.getCity().equals(this.getCity());
    } else {
      return false;
    }

  }
}
Making a Class Cloneable - Java Object Oriented Design

Introduction

Demo Code

Result

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