datetime - See if the current time falls within a specific range of time in the current day in Java

Question

I am sure this was done 1000 times in 1000 different places. The question is I want to know if there is a better/standard/faster way to check if current "time" is between two time values given in hh:mm:ss format. For example, my big business logic should not run between 18:00:00 and 18:30:00. So here is what I had in mind:

 public static  boolean isCurrentTimeBetween(String starthhmmss, String endhhmmss) throws ParseException{
  DateFormat hhmmssFormat = new SimpleDateFormat("yyyyMMddhh:mm:ss");
  Date now = new Date();
  String yyyMMdd = hhmmssFormat.format(now).substring(0, 8);

  return(hhmmssFormat.parse(yyyMMdd+starthhmmss).before(now) &&
    hhmmssFormat.parse(yyyMMdd+endhhmmss).after(now));
 }

Example test case:

  String doNotRunBetween="18:00:00,18:30:00";//read from props file
  String[] hhmmss = downTime.split(",");
  if(isCurrentTimeBetween(hhmmss[0], hhmmss[1])){
   System.out.println("NOT OK TO RUN");
  }else{
   System.out.println("OK TO RUN");
  }

What I am looking for is code that is better

• in performance
• in looks
• in correctness

What I am not looking for

• third-party libraries
• Exception handling debate
• variable naming conventions
• method modifier issues

Answer 1

this is all you should need to do, this method is loosely coupled from the input and highly coherent.

boolean isNowBetweenDateTime(final Date s, final Date e)
{
    final Date now = new Date();
    return now.after(s) && now.before(e);
}

how you get the Date objects for start and end is irrelevant to comparing them. You are making things way more complicated than you need to with passing String representations around.

Here is a better way to get the start and end dates, again loosely coupled and highly coherent.

private Date dateFromHourMinSec(final String hhmmss)
{
    if (hhmmss.matches("^[0-2][0-9]:[0-5][0-9]:[0-5][0-9]$"))
    {
        final String[] hms = hhmmss.split(":");
        final GregorianCalendar gc = new GregorianCalendar();
        gc.set(Calendar.HOUR_OF_DAY, Integer.parseInt(hms[0]));
        gc.set(Calendar.MINUTE, Integer.parseInt(hms[1]));
        gc.set(Calendar.SECOND, Integer.parseInt(hms[2]));
        gc.set(Calendar.MILLISECOND, 0);
        return gc.getTime();
    }
    else
    {
        throw new IllegalArgumentException(hhmmss + " is not a valid time, expecting HH:MM:SS format");
    }
}

Now you can make two well named method calls that will be pretty self documenting.