SourceMaking

abstract class Generalization {

   // 1. Standardize the skeleton of an algorithm in a "template" method

   public void findSolution() {

      stepOne();

      stepTwo();

      stepThr();

      stepFor();

   }

   // 2. Common implementations of individual steps are defined in base class

   protected void stepOne() { System.out.println( "Generalization.stepOne" ); }

   // 3. Steps requiring peculiar impls are ";placeholders" in the base class

   abstract protected void stepTwo();

   abstract protected void stepThr();

   protected void stepFor() { System.out.println( "Generalization.stepFor" ); }

}

 

abstract class Specialization extends Generalization {

   // 4. Derived classes can override placeholder methods

   // 1. Standardize the skeleton of an algorithm in a "template" method

   protected void stepThr() {

      step3_1();

      step3_2();

      step3_3();

   }

   // 2. Common implementations of individual steps are defined in base class

   protected void step3_1() { System.out.println( "Specialization.step3_1" ); }

   // 3. Steps requiring peculiar impls are "placeholders" in the base class

   abstract protected void step3_2();

   protected void step3_3() { System.out.println( "Specialization.step3_3" ); }

}

 

class Realization extends Specialization {

   // 4. Derived classes can override placeholder methods

   protected void stepTwo() { System.out.println( "Realization   .stepTwo" ); }

   protected void step3_2() { System.out.println( "Realization   .step3_2" ); }

   // 5. Derived classes can override implemented methods

   // 6. Derived classes can override and "call back to" base class methods

   protected void stepFor() {

      System.out.println( "Realization   .stepFor" );

      super.stepFor();

}  }

 

class TemplateMethodDemo {

   public static void main( String[] args ) {

      Generalization algorithm = new Realization();

      algorithm.findSolution();

}  }