代码如下：

public class Test {
    public static void main(String[] args) {
        Cool cool=new Cool();
        Cool.Inner in=cool.new Inner();
    }
}

class Cool {
    private static int info=5;
   
    static class Inner {            //貌似这里编译出错
        public void print() {
            System.out.println(info);
        }
    }
}

public class Test {
    public static void main(String[] args) {
//        Cool cool=new Cool();
        Cool.Inner in=new Cool.Inner();//貌似这里编译出错
    }
}

class Cool {
    private static int info=5;
    
    static class Inner {            
        public void print() {
            System.out.println(info);
        }
    }
}

好像略懂了一点儿，谢啦！