yanrui92的专栏

1.看了有关immutable class的资料， An object is considered immutable if its state cannot change after it is constructed. Maximum reliance on immutable objects is widely accepted as a sound strategy for creat

1 关于File关键点File doesn't really mean a file, it means "FilePath". It can represent either the name of a particular file or the names of a set of files in a directory. 用list 来返回一个当前path下面的所有的文件还有文件夹的名

今天看了java的initialization的一章， 感觉又学到了一点心得东西