title: is the int value of String.hashCode() unique?
body: <p>I encountered a problem days ago.Now i have tens of millions of words,type of string. now i decide to keep them in database and use index to keep them unique.And i do not want to compare the original words to keep them unique. I would like to make sure whether the hashCode() method of a string can be unique , will it not be changed if a use another laptop or different time or something like that?</p>