hhhhhhh/BasicShapeConverter.java

package tiaozhanti;

import jichuti.Circle;
import jichuti.Square;

public class BasicShapeConverter implements ShapeConverter {
    @Override
    public Shape convert(Shape source, Class<? extends Shape> targetType) {
        // 圆形 → 椭圆形（保持面积相等）
        if (source instanceof Circle && targetType == Oval.class) {
            Circle circle = (Circle) source;
            double radius = circle.getRadius();
            return new Oval(circle.getColor(), radius, radius);  // 椭圆退化为圆形
        }

        // 椭圆形 → 圆形（保持面积相等）
        if (source instanceof Oval && targetType == Circle.class) {
            Oval oval = (Oval) source;
            double area = oval.getArea();
            double radius = Math.sqrt(area / Math.PI);  // 从面积反推半径
            return (Shape) new Circle(oval.getColor(), radius);
        }

        // 正方形 → 圆形（保持面积相等）
        if (source instanceof Square && targetType == Circle.class) {
            Square square = (Square) source;
            double area = square.getArea();
            double radius = Math.sqrt(area / Math.PI);
            return (Shape) new Circle(square.getColor(), radius);
        }

        throw new UnsupportedOperationException(
            "不支持转换：" + source.getClass().getSimpleName() + " → " + targetType.getSimpleName()
        );
    }
}