Factory method design pattern

Factory method design pattern

This is an extension of Factory design pattern. Let suppose even though different objects are created and returned based on the factory arguments. What if there is a generic pre/post processing that’s required before returning the object from the factory.

public interface I_Animal {

     

      public void makeSound();

}

public class Cat implements I_Animal {

      @Override

      public void makeSound() {

            System.out.println("Meaow !! I just had food");

      }

}

public class Dog implements I_Animal {

      @Override

      public void makeSound() {

            System.out.println("Bark !! I just had food");

      }

}

public class Factory {

     

      private static final Factory instance = new Factory();

     

      private Factory() {

            super();

      }

      public static Factory getInstance() {

            return instance;

      }

     

      private I_Animal getAnimal(String name) {

            if(name.equals("cat")) {

                  return new Cat();

            } else {

                  return new Dog();

            }

      }

     

      public I_Animal factoryMethod(String name) {

            I_Animal animal = getAnimal(name);

            System.out.println("Food served to "+name+" "+animal.getClass().getCanonicalName());

            return animal;

      }

}

public class MainClass {

     

      public static void main(String[] args) {

            I_Animal animal1 = Factory.getInstance().factoryMethod("cat");

            animal1.makeSound();

            I_Animal animal2 = Factory.getInstance().factoryMethod("dog");

            animal2.makeSound();

      }

}


Code link : https://github.com/sksumit1/DesignPatterns