Java Utililty Methods Random Number

String randnum = "";
for (int i = 0; i < num; i++) {
    Random rand = new Random();
    randnum += rand.nextInt(10);
return randnum;

return rand.nextInt(maxNumber);

DecimalFormat formatter = new DecimalFormat(decimalFormat);
return Double.parseDouble(formatter.format(Math.random() * max));

final Random generator = new Random();
return generator.nextLong();

return rnd.nextInt();

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssS");
Date now = new Date();
String s = sdf.format(now);
Random rd = new Random();
int rdNum = rd.nextInt(1000);
String subDir = s + String.valueOf(rdNum);
return subDir;

StringBuffer sb = new StringBuffer();
sb.append(dataToString(new java.util.Date(), DATE_FORMAT_YYYYMMDDHHMM));
sb.append(String.valueOf(Math.round(Math.random() * 8999 + 1000)));
return sb.toString();

if (pSngEnd < pSngBegin) {
    throw new IllegalArgumentException("pSngEnd must not smaller than pSngBegin");
return (pSngEnd - pSngBegin) * Math.random() + pSngBegin;

Random random = new Random();
StringBuffer strNum = new StringBuffer();
for (int i = 0; i < len; i++) {
    int num = random.nextInt(10);
    strNum.append(num);
return strNum.toString();

String randomStr = "abcdefghijklmnopqrstuvwxyz0123456789";
final int maxNum = 36;
int i;
int count = 0;
char[] str = randomStr.toCharArray();
StringBuffer pwd = new StringBuffer("");
Random r = new Random();
while (count < pwd_len) {
...