Java Utililty Methods Random String

final String AB = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
final Random rnd = new Random();
final StringBuilder sb = new StringBuilder(len);
for (int i = 0; i < len; i++) {
    sb.append(AB.charAt(rnd.nextInt(AB.length())));
return sb.toString();

final StringBuffer sb = new StringBuffer();
final Random rand = new Random();
for (int i = 0; i < length; i++)
    sb.append((char) ((Math.abs(rand.nextInt()) % 26) + 65));
return sb.toString();

final StringBuilder randomString = new StringBuilder(size);
for (int i = 0; i < size; i++) {
    randomString.append(getRandomCharacter());
return randomString.toString();

StringBuilder sb = new StringBuilder(size);
for (int i = 0; i < size; i++) {
    sb.append(AB.charAt(rnd.nextInt(AB.length())));
return sb.toString();

String vNumeros = "0123456789";
String vMayusculas = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
String vMinusculas = "abcdefghijklmnopqrstuvwxyz";
String vSimbolos = "!@#$%&*-_+,./|:;()[]{}<>?= ";
StringBuilder busqueda = new StringBuilder();
if (mayusculas) {
    busqueda.append(vMayusculas);
if (minusculas) {
    busqueda.append(vMinusculas);
if (numeros) {
    busqueda.append(vNumeros);
if (simbolos) {
    busqueda.append(vSimbolos);
return getRandomString(cantidad, busqueda.toString(), repetir);

StringBuilder sb = new StringBuilder();
for (int i = 0; i < count; i++)
    sb.append(getRandomChar());
return sb.toString();

Random rnd = getRandom();
char[] s = new char[len];
for (int i = 0; i < len; i++) {
    char c;
    if (rnd.nextInt(3) == 0) {
        c = vowels[rnd.nextInt(vowels.length)];
    } else {
        c = consonants[rnd.nextInt(consonants.length)];
...

Random rand = new Random();
StringBuffer sb = new StringBuffer();
for (int i = 0; i < len; i++) {
    sb = sb.append(RANDOM_CHARSET[rand.nextInt(RANDOM_CHARSET.length)]);
return sb.toString();

Random rnd = new Random();
StringBuilder sb = new StringBuilder(len);
for (int i = 0; i < len; i++) {
    sb.append(RANDOM_CHARACTERS.charAt(rnd.nextInt(RANDOM_CHARACTERS.length())));
return sb.toString();

return getRandomString(len, RANDOM_TYPE_NORMAL);