public static String getRandomString() {

String chose = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";// "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

char display[] = { '0', 'a', '0', 'c', '0', 'd', '0' };

char ran[] = { '0', '0', '0', '0' };

Random rand = new Random();

for (int i = 0; i < 4; i++) {

char temp = chose.charAt(rand.nextInt(chose.length()));

display[i * 2] = temp;

ran[i] = temp;

}

 

String random = String.valueOf(display);

return random;

}