Question

遵循超类/子类关系：

public abstract class A {
  public Class<? extends A> getSubClass() {
      Class<? extends A> clazz = ???
    }
}

public class B extends A {
  /* some implementation*/
}

public class Foo {
  public static void main(String... args) {
    A a = new B();
    a.getSubClass();
  }
}

b.getSubClass()是否有办法返回acutall子类类型？

Answer 1

此

package test;

public class SubClass {
    public static void main(String[] args) {
        final A b = new B();

        System.out.println("Class: " + b.getSubClass().getName());
    }

    public static abstract class A {
        public Class<? extends A> getSubClass() {
            return this.getClass();
        }
    }

    public static class B extends A {
        // No further implementation
    }
}

产生

Class: test.SubClass$B

即使在超类方法中，实际的类也是子类。

超类方法中子类的类对象

1 个答案: