Java Utililty Methods Random Number

List of utility methods to do Random Number

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Description

The list of methods to do Random Number are organized into topic(s).

Method

Map createParameters(int numberOfParameters)
create Parameters

int defaultKeyLength = 8;
while (numberOfParameters > Math.pow(ALPHABET.length, defaultKeyLength)) {
 defaultKeyLength *= 2;
Map<String, String> parameters = new HashMap<>();
for (int i = 0; i < numberOfParameters; i++) {
 parameters.put(generateAlphabetString(defaultKeyLength), generateAlphabetString(defaultKeyLength));
return parameters;

String createRandomFilename()
create Random Filename

return String.valueOf(System.currentTimeMillis());

String createRandomHexNumber(int length)
create Random Hex Number

Random random = new Random(System.currentTimeMillis());
char[] result = new char[length];
for (int i = 0; i < length; i++) {
 int r = random.nextInt(16);
 result[i] = Integer.toHexString(r).charAt(0);
return new String(result);

int createRandomNumber()
create Random Number

Random randomGenerator = new Random();
return randomGenerator.nextInt(RANDOM_RANGE);

int createRandomNumber(int index)
create Random Number

int value = (int) (Math.random() * index + 1);
return value;

int[] distinctInts(int from, int to, int number)
Returns from the range of [from, to] (inclusive).

if (from >= to)
 throw new IllegalArgumentException("From cannot be larget than to!");
List<Integer> lst = new ArrayList<Integer>();
for (int i = from; i <= to; i++)
 lst.add(i);
Collections.shuffle(lst, rand);
int[] ret = new int[number];
for (int i = 0; i < number; i++)
...

StringBuffer generateRandomNum(int i)
generate Random Num

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

int generateRandomNum(int passNumber)
generate Random Num

int range = passNumber + 1;
randomNum = rn.nextInt(range);
return randomNum;

int[] generateRandomNumb(int randomSize, int range)
generate Random Numb

int[] randomNumb = new int[randomSize];
for (int i = 0; i < randomSize; i++) {
 randomNumb[i] = (int) (Math.random() * range) + 1;
return randomNumb;

int generateRandomNumber()
Generate a random number between 5 to 16

Random randomGenerator = new Random();
return randomGenerator.nextInt(11) + 5;