How can I generate a random Verhoeff number in Apache Jmeter? - testing

Question

Need to pass a new Verhoeff Number every time I execute my script. The already used Verhoeff number is rejected by my application, as a business validation. Can someone help with the script for this?

Answer 1

The Java algorithm implementation is available at the Wikipedia page
In JMeter it's recommended to use Groovy for scripting so you will need to amend it to look like:
/**
* #see <ahref="http://en.wikipedia.org/wiki/Verhoeff_algorithm" > More Info</a>
* #see <ahref="http://en.wikipedia.org/wiki/Dihedral_group" > Dihedral Group</a>
* #see <ahref="http://mathworld.wolfram.com/DihedralGroupD5.html" > Dihedral Group Order 10</a>
* #author Colm Rice
*/
public class Verhoeff {
// The multiplication table
static int[][] d = new int[][]
{
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[1, 2, 3, 4, 0, 6, 7, 8, 9, 5],
[2, 3, 4, 0, 1, 7, 8, 9, 5, 6],
[3, 4, 0, 1, 2, 8, 9, 5, 6, 7],
[4, 0, 1, 2, 3, 9, 5, 6, 7, 8],
[5, 9, 8, 7, 6, 0, 4, 3, 2, 1],
[6, 5, 9, 8, 7, 1, 0, 4, 3, 2],
[7, 6, 5, 9, 8, 2, 1, 0, 4, 3],
[8, 7, 6, 5, 9, 3, 2, 1, 0, 4],
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
};
// The permutation table
static int[][] p = new int[][]
{
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
[1, 5, 7, 6, 2, 8, 3, 0, 9, 4],
[5, 8, 0, 3, 7, 9, 6, 1, 4, 2],
[8, 9, 1, 6, 0, 4, 3, 5, 2, 7],
[9, 4, 5, 3, 1, 2, 6, 8, 7, 0],
[4, 2, 8, 6, 5, 7, 3, 9, 0, 1],
[2, 7, 9, 3, 8, 0, 6, 4, 1, 5],
[7, 0, 4, 6, 9, 1, 3, 2, 5, 8]
};
// The inverse table
static int[] inv = [0, 4, 3, 2, 1, 5, 6, 7, 8, 9];
/*
* For a given number generates a Verhoeff digit
*
*/
public static String generateVerhoeff(String num) {
int c = 0;
int[] myArray = stringToReversedIntArray(num);
for (int i = 0; i < myArray.length; i++) {
c = d[c][p[((i + 1) % 8)][myArray[i]]];
}
return Integer.toString(inv[c]);
}
/*
* Validates that an entered number is Verhoeff compliant.
* NB: Make sure the check digit is the last one.
*/
public static boolean validateVerhoeff(String num) {
int c = 0;
int[] myArray = stringToReversedIntArray(num);
for (int i = 0; i < myArray.length; i++) {
c = d[c][p[(i % 8)][myArray[i]]];
}
return (c == 0);
}
/*
* Converts a string to a reversed integer array.
*/
private static int[] stringToReversedIntArray(String num) {
int[] myArray = new int[num.length()];
for (int i = 0; i < num.length(); i++) {
myArray[i] = Integer.parseInt(num.substring(i, i + 1));
}
myArray = reverse(myArray);
return myArray;
}
/*
* Reverses an int array
*/
private static int[] reverse(int[] myArray) {
int[] reversed = new int[myArray.length];
for (int i = 0; i < myArray.length; i++) {
reversed[i] = myArray[myArray.length - (i + 1)];
}
return reversed;
}
}
and in order to call this and to store the result into a JMeter Variable you need to use vars shorthand to JMeterVariables class instance, something like:
vars.put('myVar', Verhoeff.generateVerhoeff("your-source-number-here"))
and then you will be able to refer the generated value as ${myVar} where required.