Creation Pattern - Abstract Factory Pattern

1. What is the abstract factory pattern?

    The abstract factory pattern provides the best way to create objects. In the abstract factory pattern, abstract methods are responsible for creating a factory of related objects, without the need to explicitly specify their classes.

2. Usage scenarios

    Similar to factory pattern

3. How to implement

    Provide an abstract class responsible for creating related objects, which are implemented in subclasses.

4. Advantages When adding a product, you only need to create a product object and the factory class of the product.

     

5. Disadvantages

    。。 。

6. Application examples and UML
    

        Code example:

            Create a variety of geometric shapes, circles, rectangles, squares

        UML:

        

7. Code implementation

 7.1 Abstract class AbstractShapeFactory

public abstract class AbstractShapeFactory {

	public abstract Shape getShape();
	
}

7.2 Circle Factory Class CircleFactory

public class CircleFactory extends AbstractShapeFactory{

	@Override
	public Shape getShape() {
		return new Circle();
	}

}

7.3 Rectangle Factory Class RectangleFactory

public class RectangleFactory extends AbstractShapeFactory{

	@Override
	public Shape getShape() {
		return new Rectangle();
	}

}

7.4 Square Factory Class SquareFactory    

public class SquareFactory extends AbstractShapeFactory{

	@Override
	public Shape getShape() {
		return new Square();
	}

}

8. Test class

8.1 Test class

public class AbstractFactoryTest {
	
	@Test
	public void test(){
		
		CircleFactory circleFactory = new CircleFactory();
		Shape circle = circleFactory.getShape();
		circle.draw();
		
		RectangleFactory rectangleFactory = new RectangleFactory();
		Shape rectangle = rectangleFactory.getShape();
		rectangle.draw();
		
		SquareFactory squareFactory = new SquareFactory();
		Shape square = squareFactory.getShape();
		square.draw();
	}

}

8.2 Test Results

this is Circle drawing
this is Rectangle drawing
this is Square drawing