java中，除了类内部，什么情况下可以访问private变量？

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
package com.stone.javacore;

public class PrivateAccess {
    public static class Line{
        private double k;
        private double b;
        private boolean isVertical;

        public Line(double k, double b, boolean isVertical){
            this.k = k;
            this.b = b;
            this.isVertical = isVertical;
        }

    }

    public static  void main (String[] args){
        System.out.println(new Line(1, 2, false).k);  // 1.0
    }
}

原因JLS chapter on accessibility

Otherwise, if the member or constructor is declared private, then access is permitted if and only if it occurs within the body of the top level class (§7.6) that encloses the declaration of the member or constructor.