code: public static int indexOfAnyBut(String str, String searchChars) {
        if (isEmpty(str) || isEmpty(searchChars)) {
            return -1;
        }
        for (int i = 0; i < str.length(); i++) {
            if (searchChars.indexOf(str.charAt(i)) < 0) {
                return i;
            }
        }
        return -1;
    }
docs: <p>Search a String to find the first index of any
  character not in the given set of characters.</p>
  
  <p>A <code>null</code> String will return <code>-1</code>.
  A <code>null</code> search string will return <code>-1</code>.</p>
  
  <pre>
  GosuStringUtil.indexOfAnyBut(null, *)            = -1
  GosuStringUtil.indexOfAnyBut("", *)              = -1
  GosuStringUtil.indexOfAnyBut(*, null)            = -1
  GosuStringUtil.indexOfAnyBut(*, "")              = -1
  GosuStringUtil.indexOfAnyBut("zzabyycdxx", "za") = 3
  GosuStringUtil.indexOfAnyBut("zzabyycdxx", "")   = 0
  GosuStringUtil.indexOfAnyBut("aba","ab")         = -1
  </pre>
  
  @param str  the String to check, may be null
  @param searchChars  the chars to search for, may be null
  @return the index of any of the chars, -1 if no match or null input
  @since 2.0