How can I convert a Gregorian string to a Gregorian calendar?
I need to calculate something based on a calendar date, but I am getting the full Gregorian String value.
For example i / p is received {may be - "new GregorianCalendar().toString()"} as String :- java.util.GregorianCalendar[time=1410521241348,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Europe/London",offset=0,dstSavings=3600000,useDaylight=true,transitions=242,lastRule=java.util.SimpleTimeZone[id=Europe/London,offset=0,dstSavings=3600000,useDaylight=true,startYear=0,startMode=2,startMonth=2,startDay=-1,startDayOfWeek=1,startTime=3600000,startTimeMode=2,endMode=2,endMonth=9,endDay=-1,endDayOfWeek=1,endTime=3600000,endTimeMode=2]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2014,MONTH=8,WEEK_OF_YEAR=37,WEEK_OF_MONTH=2,DAY_OF_MONTH=12,DAY_OF_YEAR=255,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=2,AM_PM=1,HOUR=0,HOUR_OF_DAY=12,MINUTE=27,SECOND=21,MILLISECOND=348,ZONE_OFFSET=0,DST_OFFSET=3600000]
I want to extract the date value of a calendar to handle further calculations.
source to share
The other answers are too complicated or wrong. The following will give you milliseconds since epoch, which is a universal timestamp that you can easily convert to most time representation classes, including Calendar
either Date
:
Pattern gregorianPattern = Pattern.compile("^java.util.GregorianCalendar\\[time=(\\d+).*");
Matcher matcher = gregorianPattern.matcher(param);
if(matcher.matches()) {
return Long.parseLong(matcher.group(1));
}
source to share
You can find the time in the input string and convert it to the Gregorian calendar. Then you will need to set your timezone as specified in the ZoneInfo field. Perhaps something like this:
String calendarAsString="java.util.GregorianCalendar[time=1410521241348,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id=\"Europe/London\",offset=0,dstSavings=3600000,useDaylight=true,transitions=242,lastRule=java.util.SimpleTimeZone[id=Europe/London,offset=0,dstSavings=3600000,useDaylight=true,startYear=0,startMode=2,startMonth=2,startDay=-1,startDayOfWeek=1,startTime=3600000,startTimeMode=2,endMode=2,endMonth=9,endDay=-1,endDayOfWeek=1,endTime=3600000,endTimeMode=2]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2014,MONTH=8,WEEK_OF_YEAR=37,WEEK_OF_MONTH=2,DAY_OF_MONTH=12,DAY_OF_YEAR=255,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=2,AM_PM=1,HOUR=0,HOUR_OF_DAY=12,MINUTE=27,SECOND=21,MILLISECOND=348,ZONE_OFFSET=0,DST_OFFSET=3600000]";
int timeStart=calendarAsString.indexOf("time=")+5;
int timeEnd=calendarAsString.indexOf(',');
String timeStr=calendarAsString.substring(timeStart, timeEnd);
long timeInMillis=Long.parseLong(timeStr);
int timezoneIdStart=calendarAsString.indexOf("\"")+1;
int timezoneIdEnd=calendarAsString.indexOf("\",");
String timeZoneStr=calendarAsString.substring(timezoneIdStart, timezoneIdEnd);
System.out.println("time="+timeInMillis+" zone="+timeZoneStr);
Calendar calendar=Calendar.getInstance(TimeZone.getTimeZone(timeZoneStr));
calendar.setTimeInMillis(timeInMillis);
System.out.println(calendarAsString);
System.out.println(calendar);
or you can use regex for this, instead
String regex="time=([0-9]*),.*ZoneInfo\\[id=\"([^\"]*)\"";
Pattern pattern=Pattern.compile(regex);
Matcher matcher=pattern.matcher(calendarAsString);
matcher.find();
timeStr=matcher.group(1);
timeInMillis=Long.parseLong(timeStr);
timeZoneStr=matcher.group(2);
System.out.println("time="+timeInMillis+" zone="+timeZoneStr);
calendar=Calendar.getInstance(TimeZone.getTimeZone(timeZoneStr));
calendar.setTimeInMillis(timeInMillis);
System.out.println(calendar);
Note. If you just want to use a calendar date value, you can create it from timeInMillis without having to reverse engineer the entire GregorianCalendar object (and without having to find the timezone if you don't want to).
Date date=new Date(timeInMillis);
source to share
GregorianCalendar g=new GregorianCalendar(1975, 5, 7);
Date d=g.getTime();
System.out.println(g.toString());
SimpleDateFormat formatter=new SimpleDateFormat("yyyy MM dd");
System.out.println(formatter.format(d));
This is the way to get the date from GregorianCalendar. I want this to help you
By adding more to this, you can get whatever information you want using the format. It's just a matter of providing the correct format.
Example:
Adding z or Z provides time zone information
"yyyy MM dd z" - 2014 10 12 PDT
"yyyy MM dd Z" - 2014 10 12 -0700
Adding "T" will result in something like this:
"yyyy-MM-dd'T'HH:mm:ss.sssZ" - 2014-10-12T14:23:51.890+0530
This HH features watches in 24-hour mm min format. ss seconds sss milliseconds.
source to share