给孩子的诗

年轻的时候,我认为我肯定能成为伟大的艺术家,但我现在并不是。我有我的局限性。但是你知道,即便你自身有局限性,只要你尽了全力,只要你不出卖自己,不被不值得的东西收买,你仍然可以过上美好的生活。你不必一生都鞭挞自己,你又不是达芬奇,我也不是。——伍迪·艾伦

When you are old and grey and full of sleep,
And nodding by the fire, take down this book,
And slowly read, and dream of the soft look
Your eyes had once, and of their shadows deep;
How many loved your moments of glad grace,
And loved your beauty with love false or true,
But one man loved the pilgrim soul in you,
And loved the sorrows of your changing face;
And bending down beside the glowing bars,
Murmur, a little sadly, how Love fled
And paced upon the mountains overhead
And hid his face amid a crowd of stars.

当你老了,头发白了,睡意昏沉…

 

java学习笔记(1)

类加载

  • 当程序创建了第一个对类的静态成员的引用(如类的静态变量、静态方法、构造方法——构造方法也是静态的)时,才会加载该类。
  • RTTI
    • 向上转型或向下转型(upcasting and downcasting),在java中,向下转型(父类转成子类)需要强制类型转换
    • Class对象(用了Class对象,不代表就是反射,如果只是用Class对象cast成指定的类,那就还是传统的RTTI)
    • instanceof或isInstance()

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