Java类示例

接口类

/**
 * 接口：形状
 */
public interface Shape {
    /**
     * 获取体积
     *
     * @return 形状的体积
     */
    int getArea();
    /**
     * 获取名称
     */
    String getName();
}

实现类 Rectangle

/**
 * 矩形
 */
public class Rectangle implements Shape {
    /** TAG */
    private static final String TAG = "矩形";
    /** 宽 */
    private int width;
    /** 长 */
    private int length;
    public Rectangle(int width, int length) {
        this.width = width;
        this.length = length;
    }
    @Override
    public int getArea() {
        return width * length;
    }
    @Override
    public String getName() {
        return TAG;
    }
}

实现类 Square

/**
 * 正方形
 */
public class Square extends Rectangle {
    /** TAG */
    private static final String TAG = "正方形";
    public Square(int length) {
        super(length, length);
    }
    @Override
    public String getName() {
        return TAG;
    }
}