java - 与私有(private)构造函数混淆

Question

在java中研究，如果一个类有私有(private)构造函数，它不能被继承为super()，不能被调用，那么为什么在内部类的情况下这段代码可以编译:

public class TestMe2 { 
    class Singleton { 
        private Singleton() { 
        } 
    } 
    class BB extends Singleton {  
    } 

    public void callMe(){ 
        Singleton sing=new BB(); 
    } 
}

Answer 1

因为一个公共(public)外部类的2个内部类可以访问它们各自的私有(private)成员。

引自the JLS :

A private class member or constructor is accessible only within the body of the top level class (§7.6) that encloses the declaration of the member or constructor.