Dependency Inversion Design Principle

If high level classes are not working directly with low level classes and they are using interfaces as an abstract layer then we will implement this principle with creational design pattern.

Bad Scenario :

Robot

public class Robot {

      public void work (){

            System.out.println("Robot's work.");

      }

}

Worker

public class Worker {

      public void work(){

            System.out.println("Worker's Work.");

      }

}

WorkManager

public class WorkManager {

      public void manage(Worker worker){

            worker.work();

      }

     

      public void manager(Robot robot){

            robot.work();

      }

}

Good Scenario :

IWork

public interface IWork {

      public void work();

}

Robot

public class Robot implements IWork {

      public void work(){

            System.out.println("Robot's work.");

      }

}

Worker

public class Worker implements IWork {

      public void work(){

            System.out.println("Worker's Work.");

      }

}

WorkManager

public class WorkManager {

      public void manage(IWork work){

            work.work();

      }

}