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

public static String generateSessionKey(int length){
    String alphabet =
        new String("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"); // 9

    int n = alphabet.length(); // 10

    String result = new String();
    Random r = new Random(); // 11

    for (int i=0; i