Java vs Clojure: Factory pattern

Java 

Shape interface: 

public interface Shape { 

public void draw(); 

} 

Concrete Shape implementations: 

 public class Circle implements Shape { 

@Override 

public void draw() { 

System.out.println("circle"); 

} 

} 

 public class Square implements Shape { 

@Override 

public void draw() { 

System.out.println("square"); 

} 

} 

 Shape Factory: 

 public class ShapeFactory { 

public Shape getShape(String shapeType){ 

if(shapeType.equals("circle")){ 

return new Circle(); 

} else if(shapeType.equals("square")){ 

return new Square(); 

} 

return null; 

} 

} 

 Usage: 

new ShapeFactory().getShape("circle").draw(); 

new ShapeFactory().getShape("square").draw(); 

  

Clojure 

  

Shape interface: 

(defprotocol Shape 

"Shape inteface" 

(draw [this])) 

 Concrete Shape implementations: 

(deftype Circle [] 

Shape 

(draw [this] "circle")) 

  

(deftype Square [] 

Shape 

(draw [this] "square")) 

  

Shape Factory: 

(defprotocol ShapesFactory 

"Shapes Factory" 

(getShape [this t])) 

  

(deftype ShapeFactory [] 

ShapesFactory 

(getShape [this t] (cond   (= t "circle") (Circle.) 

   (= t "square") (Square.)))) 

 Usage: 

(draw (getShape (ShapeFactory.) "circle")) 

(draw (getShape (ShapeFactory.) "square"))