java - 抽象构造函数java

Question

如何从第二个和第三个获取子构造函数？ 自从 public abstract first 不起作用？

public abstract class First {

    public Point position;

    public First() {}  //how do i make this constructor like an abstract?
                      // so that it will go get Second constructor or Third
}

public class Second extends First {

    public Second (Point x) {
        position = x;
    }
}

public class Third extends First {

    public Third(Point x) {
        position = x;
    }
}

Answer 1

Java 不允许您从抽象类内部访问从抽象类派生的具体类的构造函数。但是，您可以从具体类调用父类(super class)(抽象类)构造函数。

public abstract class First{

    public Point position;

    public Plant(Point x) {
      this.position = x;
    }
}

public class Second extends First {

    public Second(Point x) {
        super(x);
    }
}