java - Regex to add digit between delimiter characters if missing -

i didn't use regex lot , need little bit of help. have situation have digits separated dot char, this:

0.0.1 1.1.12.1 20.3.4.00.1 

now ensure each number between . has 2 digits:

00.00.01 01.01.12.01 20.03.04.00.01 

how can accomplish that? thank help.

you can use string.split() accomplish this:

public static void main(string[] args) {     string[] splitstring = "20.3.4.00.1".split("\\.");     string output = "";     for(string : splitstring)     {         if(a.length() < 2)         {             = "0" + a;         }         output += + ".";     }     output = output.substring(0, output.length() - 1);     system.out.println(output); }