Regular expression to match incremental or consecutive digits

Question

I need to process a string containing all digits to ensure that it does not contain either
(a) a group of 5 or more consecutive identical digits eg. 11111
(b) a group of 5 or more incremental/decremental digits eg 12345, 98765
Also, is there a processing difference between the reluctant and greedy qualifiers?
Case (a) seems to be easy:
Pattern pattern = Pattern.compile("[0-9]{5,}?");but what about (b) ? From the documentation it seems that using capturing groups might be helpful, but they are confusing me.
Finally how do I merge multiple pattern matching strings into one overall regular expression so I can make one pass on the input to see whether it is valid or not?
Thanks
Chris

Answer 1

give this code a try
public class Test {
     static boolean check(String str) {
          loop : for (int x = 0, y; x < str.length() - 4; x += y) {
               y = 1;
                 int dif = (str.charAt(x+y) - str.charAt(x)); //assuming you don't whant 90123
                 if (dif >= -1 && dif <= 1) {
                    for (; y < 4; y++) {
                         if ((str.charAt(x+y+1) - str.charAt(x+y)) != dif) {
                              continue loop;
                    return true;
          return false;
     public static void main(String[] args) {
          System.out.println(check(args[0]));
}