Display and save only hours in int

问题

How to display only hours and using int variable? I mean print time like 20:30:44 PM, I want to store only hours, mean 20 in int variable. how to do that?

Can anybody tell me the code if you know, thanks?

回答1:

Try using Calendar's get method like:

 Calendar c = ..
 c.setTime(...);//if you have time in long coming from somewhere else
 int hour = c.get(Calendar.HOUR_OF_DAY);

回答2:

If you try to parse time from String I recommend these solutions:

String time = "20:30:44 PM"; // this is your input string
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss aa");

try {
    Date date = sdf.parse(time);

    // this is the uglier solution
    System.out.println("The hour is: "+date.getHours());

    GregorianCalendar gc = new GregorianCalendar();
    gc.setTime(date);

    // this is nicer solution
    System.out.println("The hour is: "+gc.get(Calendar.HOUR_OF_DAY));

} catch (ParseException e) {
    System.err.println("Couldn't parse string! "+e.getMessage());
}

date.getHours() and gc.get(Calendar.HOUR_OF_DAY) return int, in this example I printed it out without creating variable.

You can, of course, use regular expression to find out hour in your string but above solutions should do the trick. You can learn more about SimpleDateFormat and available patterns here. I hope I helped you a bit.

EDIT: In his comment autor noted, that date isn't static (like in String) but dynamic:

Calendar calendar = new GregorianCalendar();
int hour = calendar.get(Calendar.HOUR_OF_DAY);
System.out.println("The hour is: "+hour);

I hope this helps.

来源：https://stackoverflow.com/questions/28796710/display-and-save-only-hours-in-int

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java

time