OnJava8-Examples/reflection/Shapes.java

// reflection/Shapes.java
// (c)2021 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.stream.*;

abstract class Shape {
  void draw() {
    System.out.println(this + ".draw()");
  }
  @Override public abstract String toString();
}

class Circle extends Shape {
  @Override public String toString() {
    return "Circle";
  }
}

class Square extends Shape {
  @Override public String toString() {
    return "Square";
  }
}

class Triangle extends Shape {
  @Override public String toString() {
    return "Triangle";
  }
}

public class Shapes {
  public static void main(String[] args) {
    Stream.of(
      new Circle(), new Square(), new Triangle())
      .forEach(Shape::draw);
  }
}
/* Output:
Circle.draw()
Square.draw()
Triangle.draw()
*/