Help with math.random!

Question

I'm trying to replace all even numbers in a string with odd numbers that are produced from a random generator. I have somewhat of an idea of how to do it as far as creating an array of 5 characters(1,3,5,7,9) and then implement the math.random to take random numbers from that array. i just dont know how to execute that. for example:
"adam123456789" -->should be "adam153157739"
whereas, the underlined(5,1,7,3) should be random numbers(i just picked these for an instance). is it possible to do any form of :
Methods...
char [ ] ary = {1,3,5,7,9};
String line = "adam123456789";
line = line.replaceAll("[0,2,4,6,8]", Math.round(Math.random()*[ary]));
return line;**i'm a beginner, so i dont really know what im talking about. just seeking help. thanks!

Answer 1

ok. this is the class with all of my methods in there. just excuse the rest of it..
import java.util.Random;
public class NoVowelNoEven {
  private String str = "";
  NoVowelNoEven() {
    str = "hello";
  NoVowelNoEven(String newString) {
    str = newString;
  String getOriginal() {
    return str;
  static String getValid(String newString) {
    char[] arr = newString.toCharArray();
    String str2 = "";
    for (int i = 0; i < arr.length; i++) {
      if (isValid(arr)) {
str2 += arr[i];
return str2;
static int countValidChar(String newString) {
String validString = getValid(newString);
return validString.length();
static String replaceWithYAndOdd(String newString) {
     char [] ary = {1,3,5,7,9};
     String str3 = newString;
str3 = str3.replaceAll("[a,e,i,o,u]","y");
str3 = str3.replaceAll("[A,E,I,O,U]","Y");
     //str3 = str3.replaceAll("[0,2,4,6,8]", );
return str3;
static boolean isValid(char char2) {
switch (Character.toLowerCase(char2)) {
case 'a':
return false;
case 'e':
return false;
case 'i':
return false;
case 'o':
return false;
case 'u':
return false;
case '0':
return false;
case '2':
return false;
case '4':
return false;
case '6':
return false;
case '8':
return false;
default:
return true;