Factory Pattern

                                                            Factory Patterns

It is one of the most commonly used design pattern, it comes under creational patterns where we will create objects while hiding the internal logic.

In such type of designs we will create a separate class /factory to generate objects of concrete class based on supplied details

Let us suppose we need to create a design for Robot industries.

We have a contract to design a software for XYZRobot ltd , As per the initial requirements these people want us to design robots which must be different in design and appearance.

Based on such initial requirement we came up with a design prototype taking three types of designs into consideration

1)      RobotsLikeHuman

2)      RobotsLikeAnimal

3)      RobotsLikeMachine

Here in this design

1. We are going to create a Robot interface and concrete classes(RobotsLikeHuman,RobotsLikeAnimal,RobotsLikeMachine) will implement this interface.
2.  We will create a factory class which will generate objects known to be as RobotFactory.
3.  We will create RobotPrototype class which will use RobotFactory class to get a Robot object based on its type as needed.

                                                  XYZRobot.ltd Design

Example:

/*

 @author -- shashank

 */

package robotprototype;

 interface Robot

{

    public void design();

}

class RobotLikeHuman implements Robot

{

    public void design()

    {

        System.out.println("I am a Human");

    }

}

class RobotLikeAnimal implements Robot

{

    public void design()

    {

        System.out.println("I am an Animal");

    }

}

class RobotLikeMachine implements Robot

{

    public void design()

    {

        System.out.println("I am a Machine");

    }

}

class Robotfactory

{

    public Robot getdesign(String designtype)

    {

        if(designtype=="HUMAN")

        {

            return new RobotLikeHuman();

        }

        else if(designtype=="MACHINE")

        {

            return new RobotLikeMachine();

        }

        else if(designtype=="ANIMAL")

        {

            return new RobotLikeAnimal();

        }

        return null;

       

    }

}

public class RobotPrototype {

    /**

     * @param args the command line arguments

     */

    public static void main(String[] args) {

       

        Robotfactory rf = new Robotfactory();

       

        Robot r = rf.getdesign("HUMAN");

        r.design();

       

        Robot ra = rf.getdesign("ANIMAL");

        ra.design();

       

       

        Robot rm = rf.getdesign("MACHINE");

        rm.design();

        // TODO code application logic here

    }

   

}