How to generate a random alpha-numeric string

Question

I\'ve been looking for a simple Java algorithm to generate a pseudo-random alpha-numeric string. In my situation it would be used as a unique session/key identifie

Answer 1

A short and easy solution, but it uses only lowercase and numerics:

Random r = new java.util.Random ();
String s = Long.toString (r.nextLong () & Long.MAX_VALUE, 36);

The size is about 12 digits to base 36 and can't be improved further, that way. Of course you can append multiple instances.