Prototype Pattern Demo : Prototype Pattern « Design Pattern « Java Tutorial

1. Java Tutorial
2. Design Pattern
3. Prototype Pattern

public class PrototypeDemo {

  private Message message;

  PrototypeDemo(Message message) {
    this.message = message;
  }

  Message makeMessage() {
    return this.message.makeCopy();
  }

  public static void main(String[] args) {
    Message prototype = new EmailMessage();
    PrototypeDemo demo = new PrototypeDemo(prototype);
    System.out.println("Message " + demo.makeMessage());
  }
}

abstract class Message {

  public Message makeCopy() {
    try {
      return this.getClass().newInstance();
    } catch (InstantiationException e) {
      return null;
    } catch (IllegalAccessException e) {
      return null;
    }
  }
}

class EmailMessage extends Message {

  @Override
  public String toString() {
    return "EmailMessage";
  }

}