Get all full hours of every day of a year

问题:

I need to get / print on command line every full hour of every day of a given year, e.g. 2011 but I am struggling to code it in Java.

Has anybody ever coded this issue?

回答1:

This should work:

final DateFormat df = DateFormat.getDateTimeInstance();
final Calendar c = Calendar.getInstance();
c.clear();
for (c.set(2011, Calendar.JANUARY, 1, 0, 0, 0);
     c.get(Calendar.YEAR) == 2011;
     c.add(Calendar.HOUR_OF_DAY, 1))
  System.out.println(df.format(c.getTime()));

Notice, for example, this subtlety in the output:

Oct 30, 2011 12:00:00 AM
Oct 30, 2011 1:00:00 AM
Oct 30, 2011 2:00:00 AM
Oct 30, 2011 2:00:00 AM
Oct 30, 2011 3:00:00 AM

回答2:

you could easily solve this by using the joda-time library:

    org.joda.time.Hours.hoursBetween(
        new org.joda.time.DateMidnight(2012,1,1).toLocalDate(), 
        new org.joda.time.DateMidnight(2013,1,1).toLocalDate()
      ).getHours();

回答3:

Use Calendar, and loop day after day to manage a "String quoted" as you like by parameter needed,

You can put each line day (usually separated by a comma) in a file