有一类小实体是形状(Shape),包含矩形(Rectangle)、圆形(Circle)等，请使用工厂方法模式(FactoryMethod)实现该要求。 1)画出类结构图。 2)采用面向对象编程语言实现该工厂方法模式，并写测试程序main(进行测试。

以下是该工厂方法模式的类结构图：

+----------------------+             +------------------+
|      ShapeFactory    |------------>|       Shape      |
+----------------------+             +------------------+
|+ createShape(type)   |             |+ draw()          |
+----------------------+             |+ getType()       |
                                      +------------------+
                                               /_\
                                                |
                                                |
             +------------------+       +------------------+
             |     Rectangle    |       |      Circle      |
             +------------------+       +------------------+
             |+ draw()          |       |+ draw()          |
             |+ getType()       |       |+ getType()       |
             +------------------+       +------------------+

以下是使用 Java 编程语言实现该工厂方法模式的示例代码：

// Shape 接口
public interface Shape {
    void draw();
    String getType();
}

// Rectangle 类
public class Rectangle implements Shape {
    @Override
    public void draw() {
        System.out.println("Drawing a rectangle.");
    }

    @Override
    public String getType() {
        return "Rectangle";
    }
}

// Circle 类
public class Circle implements Shape {
    @Override
    public void draw() {
        System.out.println("Drawing a circle.");
    }

    @Override
    public String getType() {
        return "Circle";
    }
}

// ShapeFactory 类
public class ShapeFactory {
    public Shape createShape(String type) {
        if (type.equalsIgnoreCase("Rectangle")) {
            return new Rectangle();
        } else if (type.equalsIgnoreCase("Circle")) {
            return new Circle();
        }
        return null;
    }
}

// 测试程序 main
public class Main {
    public static void main(String[] args) {
        ShapeFactory factory = new ShapeFactory();

        Shape shape1 = factory.createShape("Rectangle");
        System.out.println("Shape 1 type: " + shape1.getType());
        shape1.draw();

        Shape shape2 = factory.createShape("Circle");
        System.out.println("Shape 2 type: " + shape2.getType());
        shape2.draw();
    }
}

运行测试程序 main，输出结果如下：

Shape 1 type: Rectangle
Drawing a rectangle.
Shape 2 type: Circle
Drawing a circle.