I want to get Year, Month, Day, etc from Java Date to compare with Gregorian Calendar date in Java. Is this possible?
JavaDateCompatibilityJava Problem Overview
I have a Date object in Java stored as Java's Date type.
I also have a Gregorian Calendar created date. The gregorian calendar date has no parameters and therefore is an instance of today's date (and time?).
With the java date, I want to be able to get the year, month, day, hour, minute, and seconds from the java date type and compare the the gregoriancalendar date.
I saw that at the moment the Java date is stored as a long and the only methods available seem to just write the long as a formatted date string. Is there a way to access Year, month, day, etc?
I saw that the getYear()
, getMonth()
, etc. methods for Date
class have been deprecated. I was wondering what's the best practice to use the Java Date instance I have with the GregorianCalendar
date.
My end goal is to do a date calculation so that I can check that the Java date is within so many hours, minutes etc of today's date and time.
I'm still a newbie to Java and am getting a bit puzzled by this.
Java Solutions
Solution 1 - Java
Use something like:
Date date; // your date
// Choose time zone in which you want to interpret your Date
Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("Europe/Paris"));
cal.setTime(date);
int year = cal.get(Calendar.YEAR);
int month = cal.get(Calendar.MONTH);
int day = cal.get(Calendar.DAY_OF_MONTH);
// etc.
Beware, months start at 0, not 1.
Edit: Since Java 8 it's better to use java.time.LocalDate rather than java.util.Calendar. See this answer for how to do it.
Solution 2 - Java
With Java 8 and later, you can convert the Date object to a LocalDate object and then easily get the year, month and day.
Date date = new Date();
LocalDate localDate = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate();
int year = localDate.getYear();
int month = localDate.getMonthValue();
int day = localDate.getDayOfMonth();
Note that getMonthValue()
returns an int value from 1 to 12.
Solution 3 - Java
You could do something like this, it will explain how the Date
class works.
String currentDateString = "02/27/2012 17:00:00";
SimpleDateFormat sd = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date currentDate = sd.parse(currentDateString);
String yourDateString = "02/28/2012 15:00:00";
SimpleDateFormat yourDateFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
Date yourDate = yourDateFormat.parse(yourDateString);
if (yourDate.after(currentDate)) {
System.out.println("After");
} else if(yourDate.equals(currentDate)) {
System.out.println("Same");
} else {
System.out.println("Before");
}
Solution 4 - Java
Date date = new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("EEEE");
System.out.println("DAY "+simpleDateFormat.format(date).toUpperCase());
simpleDateFormat = new SimpleDateFormat("MMMM");
System.out.println("MONTH "+simpleDateFormat.format(date).toUpperCase());
simpleDateFormat = new SimpleDateFormat("YYYY");
System.out.println("YEAR "+simpleDateFormat.format(date).toUpperCase());
EDIT: The output for date
= Fri Jun 15 09:20:21 CEST 2018
is:
DAY FRIDAY
MONTH JUNE
YEAR 2018
Solution 5 - Java
private boolean isSameDay(Date date1, Date date2) {
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(date1);
Calendar calendar2 = Calendar.getInstance();
calendar2.setTime(date2);
boolean sameYear = calendar1.get(Calendar.YEAR) == calendar2.get(Calendar.YEAR);
boolean sameMonth = calendar1.get(Calendar.MONTH) == calendar2.get(Calendar.MONTH);
boolean sameDay = calendar1.get(Calendar.DAY_OF_MONTH) == calendar2.get(Calendar.DAY_OF_MONTH);
return (sameDay && sameMonth && sameYear);
}
Solution 6 - Java
It might be easier
Date date1 = new Date("31-May-2017");
OR
java.sql.Date date1 = new java.sql.Date((new Date()).getTime());
SimpleDateFormat formatNowDay = new SimpleDateFormat("dd");
SimpleDateFormat formatNowMonth = new SimpleDateFormat("MM");
SimpleDateFormat formatNowYear = new SimpleDateFormat("YYYY");
String currentDay = formatNowDay.format(date1);
String currentMonth = formatNowMonth.format(date1);
String currentYear = formatNowYear.format(date1);
Solution 7 - Java
Date queueDate = new SimpleDateFormat("yyyy-MM-dd").parse(inputDtStr);
Calendar queueDateCal = Calendar.getInstance();
queueDateCal.setTime(queueDate);
if(queueDateCal.get(Calendar.DAY_OF_YEAR)==Calendar.getInstance().get(Calendar.DAY_OF_YEAR))
{
"same day of the year!";
}
Solution 8 - Java
@Test
public void testDate() throws ParseException {
long start = System.currentTimeMillis();
long round = 100000l;
for (int i = 0; i < round; i++) {
StringUtil.getYearMonthDay(new Date());
}
long mid = System.currentTimeMillis();
for (int i = 0; i < round; i++) {
StringUtil.getYearMonthDay2(new Date());
}
long end = System.currentTimeMillis();
System.out.println(mid - start);
System.out.println(end - mid);
}
public static Date getYearMonthDay(Date date) throws ParseException {
SimpleDateFormat f = new SimpleDateFormat("yyyyyMMdd");
String dateStr = f.format(date);
return f.parse(dateStr);
}
public static Date getYearMonthDay2(Date date) throws ParseException {
Calendar c = Calendar.getInstance();
c.setTime(date);
c.set(Calendar.SECOND, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.HOUR_OF_DAY, 0);
return c.getTime();
}
public static int compare(Date today, Date future, Date past) {
Date today1 = StringUtil.getYearMonthDay2(today);
Date future1 = StringUtil.getYearMonthDay2(future);
Date past1 = StringUtil.getYearMonthDay2(past);
return today.compare // or today.after or today.before
}
getYearMonthDay2(the calendar solution) is ten times faster. Now you have yyyy MM dd 00 00 00, and then compare using date.compare