Question

When setting issue estimates in JIRA, you can enter a string like "1d 2h 30m" and JIRA will translate this (I’m assuming) into a corresponding number of milliseconds.

Is there an available Java library that does this?

I’m using a Spring managed bean that takes a property indicating how often a directory ought to be purged, and I’d like to allow the configuration to take a human-readable string rather than an explicit number of milliseconds.

Alternatively, if there’s a better approach I’m not thinking of, I’d love to hear it.

Answer 1

The parser is not too complex:

public static long parse(String input) {
   long result = 0;
   String number = "";
   for (int i = 0; i < input.length(); i++) {
     char c = input.charAt(i);
     if (Character.isDigit(c)) { 
       number += c; 
     } else if (Character.isLetter(c) && !number.isEmpty()) {
       result += convert(Integer.parseInt(number), c);
       number = "";
     }
   }
   return result;
}

private static long convert(int value, char unit) {
  switch(unit) {
    case 'd' : return value * 1000*60*60*24;
    case 'h' : return value * 1000*60*60;         
    case 'm' : return value * 1000*60;
    case 's' : return value * 1000;
  }
  return 0;
}

The code is pretty fault tolerant, it just ignores almost anything it can’t decode (and it ignores any whitspace, so it accepts “1d 1s”, “1s 1d”, “1d20m300s” and so on).