reaching outward from a multiply nested class

wangbingfeng0

于 2019-01-05 12:04:56 发布

阅读量161

点赞数

CC 4.0 BY-SA版权

分类专栏： Thinking in Java problems in programming

本文链接：https://blog.youkuaiyun.com/wangbingfengf98/article/details/85842521

Thinking in Java 同时被 2 个专栏收录

155 篇文章

订阅专栏

problems in programming

31 篇文章

订阅专栏

本文探讨了Java中内嵌类的访问特性，演示了如何从内嵌类中透明地访问其外部类的所有成员，包括私有方法。通过具体代码示例，展示了不同层级的内嵌类如何访问上层类的私有方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

It doesn't matter how deeply an inner class is nested ---it can transparently access all members of all classed it is nested within, as seen here:

// innerclasses/MultiNestingAccess.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.

// Nested classes can access all members of all
// levels of the classes they are nested within

class MNA {
  private void f() {}

  class A {
    private void g() {}

    public class B {
      void h() {
        g();
        f();
      }
    }
  }
}

public class MultiNestingAccess {
  public static void main(String[] args) {
    MNA mna = new MNA();
    // - mna.g(); // compile error: cannot find symbol mna.g();
    MNA.A mnaa = mna.new A();
    MNA.A.B mnaab = mnaa.new B();
    mnaab.h(); // can access private method f(), g()
  }
}

references:

1. On Java 8 - Bruce Eckel

2. https://github.com/wangbingfeng/OnJava8-Examples/tree/master/innerclasses