Re: Java Compare dates
On Oct 3, 10:43 am, Mangalaganesh Balasubramanian <man...@gmail.com>
wrote:
Hi,
I have a date (only hours:minutes:seconds) in a text file against
which i need to compare the current time.
The date in the text file is expressed in GMT.
How do i compare and compute the difference (i am only interested in
the hours,minutes and seconds)?
The only way looks like, creating a new Date/Calendar object from the
hh:mm:ss and setting the day, month and year from a new instance of
Date/Calendar and then computing the difference.
Yes, that's a convenient and easy way to do what you're asking.
This could run into issues when we are in the next day while GMT is
still "yesterday" during which this computation would fail.
That doesn't make sense. If you compare GMT (really, UTC) times, then you are
getting a valid comparison. You've eliminated time zone issues. What are you
referring to?
edgar wrote:
I assume you'll be comparing the time in your file to the current
time, which is the system time. So I don't think you'll have a need to
create a Date/Calendar object. You might want to look into
java.lang.System
Why the aversion to creating a Calendar or Date object?
How does System help? What's wrong with:
Calendar calNow = Calendar.getInstance();
Calendar calStored = Calendar.getInstance();
calStored.set( yearFromFile(), monthFromFile(), dayFromFile(),
hourFromFile(), minFromFile(), secFromFile() );
// DateFormat would help here
long diffInMs = calNow.getTimeInMillis() - calStored.getTimeInMillis();
etc.?
--
Lew