Is there any way to use the following simpleDateFormat:
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
and when invoking:
simpleDateFormat.parse("12:32:21 JST");
to return current date on the Date object?
For these example, it will return:
Thu Jan 01 05:32:21 EET 1970
and not:
<<today>> 05:32:21 EET <<currentYear>>
as I need.
No, SimpleDateFormat needs explicity the date in the input string. If you're using Java 8, you can go with a LocalDateTime:
LocalDateTime localDateTime = LocalDate.now().atTime(5, 32, 21);
If you want to include a time-zone, you can use ZonedDateTime.
Construct another SimpleDateFormat to print today's date:
String today = new SimpleDateFormat("yyyy/MM/dd").print(new Date());
(Be careful here: you might want to set the time zone on the SimpleDateFormat, as "today" is different in different time zones).
Update the date format to include year, month and day:
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss z");
And then prepend the date string with the date you want:
simpleDateFormat.parse(today + " " + "12:32:21 JST");
A better solution using flexible default values (today instead of 1970-01-01) would be in Java-8 with the new built-in date-time-library located in package java.time:
String input = "12:32:21 JST";
String pattern = "HH:mm:ss z";
LocalDate today = LocalDate.now(ZoneId.of("Asia/Tokyo"));
DateTimeFormatter dtf =
new DateTimeFormatterBuilder().parseDefaulting(ChronoField.YEAR, today.getYear())
.parseDefaulting(ChronoField.MONTH_OF_YEAR, today.getMonthValue()).parseDefaulting(
ChronoField.DAY_OF_MONTH,
today.getDayOfMonth()
).appendPattern(pattern).toFormatter(Locale.ENGLISH);
ZonedDateTime zdt = ZonedDateTime.parse(input, dtf);
System.out.println(zdt); // 2016-12-23T12:32:21+09:00[Asia/Tokyo]
However, I still see a small bug related to the fact that this code makes a hardwired assumption about the used zone BEFORE parsing the real zone so please handle with care. Keep in mind that the current date depends on the zone. But maybe you only need to handle a scenario where just the Japan time is used by users.
Hint: You can also parse in two steps. First step with any kind of fixed default date in order to get the zone information of the text to be parsed. And then you can use this zone information for suggested solution above. An awkward but safe procedure.
You can use this code if you want to change only the year and the day
final SimpleDateFormat simpleDateFormatHour = new SimpleDateFormat("HH:mm:ss z");
Date date = simpleDateFormatHour.parse("12:32:21 JST");
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.set(Calendar.YEAR, Calendar.getInstance().get(Calendar.YEAR));
calendar.set(Calendar.DAY_OF_YEAR, Calendar.getInstance().get(Calendar.DAY_OF_YEAR));
date = calendar.getTime();
Related
I am trying to get time (HH:MM) from below code in IST format but it still display UTC date, time.
Please help.
public static void main (String args[]) throws ParseException {
String date = "2021-07-05T14:17:00.000Z";
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
String timezoneID = timeZone.getID();
// Convert to System format from UTC
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
Date actualDate = format1.parse(date);
format1.setTimeZone(TimeZone.getTimeZone(timezoneID));
String date1 = format1.format(actualDate);
String time = date1.substring(11, 16);
String timezoneValue = TimeZone.getTimeZone(timezoneID).getDisplayName(false, TimeZone.SHORT);
String finalTime = time + " " + timezoneValue;
System.out.print(finalTime);
}
java.time
I strongly recommend that you use java.time, the modern Java date and time API, for your date and time work. Then your task becomes pretty simple. Rather than a formatter for your input format I want to define a formatter for your desired time format:
private static final DateTimeFormatter TIME_FORMATTER
= DateTimeFormatter.ofPattern("HH:mm zzz", Locale.ENGLISH);
Now the operation goes in these few lines:
String date = "2021-07-05T14:17:00.000Z";
String finalTime = Instant.parse(date)
.atZone(ZoneId.systemDefault())
.format(TIME_FORMATTER);
System.out.println(finalTime);
Output when I ran in Europe/Dublin time zone:
15:17 IST
Here IST is for Irish Summer Time. IST has several meanings, and I wasn’t sure which one you intended. Also many of the other popular time zone abbreviations are ambiguous. IST may also mean Israel Standard Time, but not here, since Israel uses Israel Daylight Time or IDT at this time of year. One other interpretation is India Standard Time used in India and Sri Lanka, So let’s try running the code in Asia/Kolkata time zone.
19:47 IST
I am exploiting the fact that your string is in ISO 8601 format, the format that the classes of java.time parse and also print as their default, that is, without any specified formatter.
What went wrong in your code?
Your bug is here:
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
You must never hardcode Z as a literal in your format pattern, which is what you are doing when enclosing it in single quotes. The Z is a UTC offset and needs to be parsed as such so that Java knows that your date and time are in UTC (which is what Z means). When you hardcode the Z, SimpleDateFormat understands the date and time to be in the default time zone of the JVM. So when afterward you try to convert into that time zone, the time of day is not changed. You’re converting into the time zone you already had. It’s a no-op.
Links
Oracle tutorial: Date Time explaining how to use java.time.
Wikipedia article: ISO 8601
Time Zone Abbreviations – Worldwide List
You are parsing the date using your default TimeZone, not UTC.
You never called format1.setTimeZone before parsing. A DateFormat uses the default timezone unless you set it to something else.
Let’s look at each line of your code:
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
That is getting the default TimeZone. You don’t need a Calendar object for that; just call TimeZone.getDefault().
String timezoneID = timeZone.getID();
There is no reason to call that. You already have a TimeZone object. Converting it to a string ID and back to a TimeZone is a pointless round-trip operation. So, you should remove all uses of timezoneID.
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
That is the problem. The DateFormat doesn’t treat the 'Z' as anything special; it’s just a literal character which the DateFormat knows not to parse.
You need to actually tell the DateFormat that it’s parsing a UTC time:
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
TimeZone utc = TimeZone.getTimeZone(ZoneOffset.UTC);
format1.setTimeZone(utc);
Date actualDate = format1.parse(date);
Instead of cutting out pieces of a formatted string, make a new DateFormat that does exactly what you want:
DateFormat timeFormat = new SimpleDateFormat("HH:mm z");
String finalTime = timeFormat.format(actualDate);
Since a SimpleDateFormat always uses the default TimeZone when it is created, there is no need to call this format object’s setTimeZone method.
I should mention that the java.time and java.time.format packages are much better for working with dates and times:
String date = "2021-07-05T14:17:00.000Z";
Instant instant = Instant.parse(date);
ZonedDateTime utcDateTime = instant.atZone(ZoneOffset.UTC);
ZonedDateTime istDateTime =
utcDateTime.withZoneSameInstant(ZoneId.systemDefault());
String finalTime = String.format("%tR %<tZ", istDateTime);
// Or:
// String finalTime = istDateTime.toLocalTime() + " "
// + itsDateTime.getZone().getDisplayName(
// TextStyle.SHORT, Locale.getDefault());
format1.setTimeZone(TimeZone.getTimeZone("Asia/Kolkata"));
is what you need since the 3-letter zone names are really deprecated. Plus:
String timezoneValue = format1.getTimeZone().getDisplayName(false, TimeZone.SHORT);
The method Calendar.getInstance() gets a calendar using the default time zone and locale - UTC±00:00.
Use "IST" instead of timeZone.getID().
Exemple:
String date="2021-07-05T14:17:00.000Z";
Calendar now = Calendar.getInstance();
TimeZone timeZone = now.getTimeZone();
String timezoneID = "IST"; // <<<<<
// Convert to System format from UTC
DateFormat format1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
Date actualDate = format1.parse(date);
format1.setTimeZone(TimeZone.getTimeZone(timezoneID));
String date1 = format1.format(actualDate);
String time = date1.substring(11, 16);
String timezoneValue = TimeZone.getTimeZone(timezoneID).getDisplayName(false, TimeZone.SHORT);
String finalTime = time + " " + timezoneValue;
System.out.print(finalTime);
Possible Solution:Convert Java Date into another Time as Date format
I went through it but does not get my answer.
I have a string "2013-07-17T03:58:00.000Z" and I want to convert it into date of the same form which we get while making a new Date().Date d=new Date();
The time should be in IST Zone - Asia/Kolkata
Thus the date for the string above should be
Wed Jul 17 12:05:16 IST 2013 //Whatever Time as per Indian Standard GMT+0530
String s="2013-07-17T03:58:00.000Z";
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
TimeZone tx=TimeZone.getTimeZone("Asia/Kolkata");
formatter.setTimeZone(tx);
d= (Date)formatter.parse(s);
Use calendar for timezones.
TimeZone tz = TimeZone.getTimeZone("Asia/Calcutta");
Calendar cal = Calendar.getInstance(tz);
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'")
sdf.setCalendar(cal);
cal.setTime(sdf.parse("2013-07-17T03:58:00.000Z"));
Date date = cal.getTime();
For this however I'd recommend Joda Time as it has better functions for this situation. For JodaTime you can do something like this:
DateTimeFormatter dtf = DateTimeFormat.forPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
DateTime dt = dtf.parseDateTime("2013-07-17T03:58:00.000Z");
Date date = dt.toDate();
A Date doesn't have any time zone. If you want to know what the string representation of the date is in the indian time zone, then use another SimpleDateFormat, with its timezone set to Indian Standard, and format the date with this new SimpleDateFormat.
EDIT: code sample:
String s = "2013-07-17T03:58:00.000Z";
DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX");
Date d = formatter.parse(s);
System.out.println("Formatted Date in current time zone = " + formatter.format(d));
TimeZone tx=TimeZone.getTimeZone("Asia/Calcutta");
formatter.setTimeZone(tx);
System.out.println("Formatted date in IST = " + formatter.format(d));
Output (current time zone is Paris - GMT+2):
Formatted Date in current time zone = 2013-07-17T05:58:00.000+02
Formatted date in IST = 2013-07-17T09:28:00.000+05
java.time
I should like to provide the modern answer. And give you a suggestion: rather than reproducing what Date.toString() would have given you, better to use the built-in format for users in the relevant locale:
String isoString = "2013-07-17T03:58:00.000Z";
String humanReadable = Instant.parse(isoString)
.atZone(userTimeZone)
.format(localizedFormatter);
System.out.println(humanReadable);
On my computer this prints
17 July 2013 at 09.28.00 IST
My snippet uses a couple of constants
private static final ZoneId userTimeZone = ZoneId.of("Asia/Kolkata");
private static final DateTimeFormatter localizedFormatter = DateTimeFormatter
.ofLocalizedDateTime(FormatStyle.LONG)
.withLocale(Locale.getDefault(Locale.Category.FORMAT));
The withLocale call is redundant when we just pass the default format locale. I put it in so you have a place to provide an explicit locale, should your users require a different one. It also has the nice advantage of making explicit that the result depends on locale, in case someone reading your code didn’t think of that.
I am using java.time, the modern Java date and time API. It is so much nicer to work with than the outdated Date, TimeZone and the notoriously troublesome DateFormat and SimpleDateFormat. Your string conforms to the ISO 8601 standard, a format that the modern classes parse as their default, that is, without any explicit formatter.
Same format as Date gave you
Of course you can have the same format as the old-fashioned Date would have given you if you so require. Just substitute the formatter above with this one:
private static final DateTimeFormatter asUtilDateFormatter
= DateTimeFormatter.ofPattern("EEE MMM dd HH:mm:ss zzz yyyy", Locale.ROOT);
Now we get:
Wed Jul 17 09:28:00 IST 2013
Link to tutorial
Read more about using java.time in the Oracle tutorial and/or find other resources out there.
I have seen this question asked multiple times and none of the answers seem to be what i need.
I have a long type variable which has an epoch time stored in it.
What i want to do is convert it to a String
for example if the epoch time stored was for today the final string would read:
17/03/2012
How would i to this?
Look into SimpleDateFormat
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
sdf.format(new Date(myTimeAsLong));
You'd create a Date from the long - that's easy:
Date date = new Date(epochTime);
Note that epochTime here ought to be in milliseconds since the epoch - if you've got seconds since the epoch, multiply by 1000.
Then you'd create a SimpleDateFormat specifying the relevant pattern, culture and time zone. For example:
SimpleDateFormat format = new SimpleDateFormat("dd/MM/yyyy", Locale.US);
format.setTimeZone(...);
Then use that to format the date to a string:
String text = format.format(date);
Date date = new Date(String);
this is deprecated.
solution
Date date = new Date(1406178443 * 1000L);
DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
format.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));
String formatted = format.format(date);
make sure multiply by 1000L
If the method should be portable, better use the default (local time) TimeZone.getDefault():
String epochToIso8601(long time) {
String format = "yyyy-MM-dd HH:mm:ss";
SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.getDefault());
sdf.setTimeZone(TimeZone.getDefault());
return sdf.format(new Date(time * 1000));
}
try this
Date date = new Date(1476126532838L);
DateFormat format = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
format.setTimeZone(TimeZone.getTimeZone("Etc/UTC"));
String formatted = format.format(date);
format.setTimeZone(TimeZone.getTimeZone("Asia/Colombo"));//your zone
formatted = format.format(date);
System.out.println(formatted);
Joda-Time
If by epoch time you meant a count of milliseconds since first moment of 1970 in UTC, then here is some example code using the Joda-Time library…
DateTimeZone timeZone = DateTimeZone.forID( "Europe/Paris" );
DateTime dateTime = new DateTime( yourMilliseconds, timeZone );
String output = DateTimeFormat.forStyle( "S-" ).withLocale( Locale.CANADA_FRENCH ).print( dateTime );
Other Epochs
That definition of epoch is common because of its use within Unix. But be aware that at least a couple dozen epoch definitions are used by various computer systems.
Time for someone to provide the modern answer (valid and recommended since 2014).
java.time
DateTimeFormatter formatter = DateTimeFormatter
.ofLocalizedDateTime(FormatStyle.LONG).withLocale(Locale.US);
String facebookTime = "1548410106047";
long fbt = Long.parseLong(facebookTime);
ZonedDateTime dateTime = Instant.ofEpochMilli(fbt).atZone(ZoneId.of("America/Indiana/Knox"));
System.out.println(dateTime.format(formatter));
The output is:
January 25, 2019 at 3:55:06 AM CST
If you wanted only the date and in a shorter format, use for example
DateTimeFormatter formatter = DateTimeFormatter
.ofLocalizedDate(FormatStyle.SHORT).withLocale(Locale.US);
1/25/19
Note how the snippet allows you to specify time zone, language (locale) and how long or short of a format you want.
Links
Oracle tutorial: Date Time explaining how to use java.time.
My example string was taken from this duplicate question
Try this...
sample Epoch timestamp is 1414492391238
Method:
public static String GetHumanReadableDate(long epochSec, String dateFormatStr) {
Date date = new Date(epochSec * 1000);
SimpleDateFormat format = new SimpleDateFormat(dateFormatStr,
Locale.getDefault());
return format.format(date);
}
Usability:
long timestamp = Long.parseLong(engTime) / 1000;
String engTime_ = GetHumanReadableDate(timestamp, "dd-MM-yyyy HH:mm:ss aa");
Result:
28-10-2014 16:03:11 pm
You need to be aware that epoch time in java is in milliseconds, while what you are converting may be in seconds. Ensure that both sides of the conversions are in milliseconds, and then you can fetch the date parameters from the Date object.
ArLiteDTMConv Utility help converting EPOUCH-UNIX Date-Time values, Form EPOUCH-UNIX-To-Date-format and Vise-Versa. You can set the result to a variable and then use the variable in your script or when passing as parameter or introduce in any DB criteria for both Window and Linux. (Download a zip file on this link)
Calendar cal = Calendar.getInstance();
cal.setTimeZone(TimeZone.getTimeZone("PST"));
cal.setTime(new Date());
System.out.println("cal:"+cal);
System.out.println("cal.getime:"+cal.getTime());
output are:
cal:java.util.GregorianCalendar[time=1325177592164,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="PST",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=PST,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2011,MONTH=11,WEEK_OF_YEAR=53,WEEK_OF_MONTH=5,DAY_OF_MONTH=29,DAY_OF_YEAR=363,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=5,AM_PM=0,HOUR=8,HOUR_OF_DAY=8,MINUTE=53,SECOND=12,MILLISECOND=164,ZONE_OFFSET=-28800000,DST_OFFSET=0]
cal.getime:Thu Dec 29 22:23:12 IST 2011
Problems facing:
While print 'cal' object getting date and time as per time zone.
cal.getTime() not displaying date and time to as per timezone.
You should represent time in UTC (java.util.Date) and then display the time in the local timezone of the user. Use DateFormat and TimeZone to do that. Read this article for more details
Unfortunately Date object always display time in GMT. You need to use something like SimpleDateFormat to display time in formatted timezone.
assign user given time into string variable then create date formatter. then parse the given string using date formatter.
String dateAndTime = "30-12-2011 12:00:00 GMT+5.30"; dateFormate
formate = new SimpleDateFormate("dd-mm-yyyy hh:mm:ss z"); Date date =
formate.parse(dateAndTime );
Date object is Java doesn't store the TimeZone info.
If you do
new Date()
this is the current local time of the machine/jvm.
To print it with the default/local timezone info:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss z");
System.out.println(sdf.format(new Date()));
I need a Java program to get the current date without a timestamp:
Date d = new Date();
gives me date and timestamp.
But I need only the date, without a timestamp. I use this date to compare with another date object that does not have a timestamp.
On printing
System.out.println("Current Date : " + d)
of d it should print May 11 2010 - 00:00:00.
A java.util.Date object is a kind of timestamp - it contains a number of milliseconds since January 1, 1970, 00:00:00 UTC. So you can't use a standard Date object to contain just a day / month / year, without a time.
As far as I know, there's no really easy way to compare dates by only taking the date (and not the time) into account in the standard Java API. You can use class Calendar and clear the hour, minutes, seconds and milliseconds:
Calendar cal = Calendar.getInstance();
cal.clear(Calendar.HOUR_OF_DAY);
cal.clear(Calendar.AM_PM);
cal.clear(Calendar.MINUTE);
cal.clear(Calendar.SECOND);
cal.clear(Calendar.MILLISECOND);
Do the same with another Calendar object that contains the date that you want to compare it to, and use the after() or before() methods to do the comparison.
As explained into the Javadoc of java.util.Calendar.clear(int field):
The HOUR_OF_DAY, HOUR and AM_PM fields are handled independently and the the resolution rule for the time of day is applied. Clearing one of the fields doesn't reset the hour of day value of this Calendar. Use set(Calendar.HOUR_OF_DAY, 0) to reset the hour value.
edit - The answer above is from 2010; in Java 8, there is a new date and time API in the package java.time which is much more powerful and useful than the old java.util.Date and java.util.Calendar classes. Use the new date and time classes instead of the old ones.
You could always use apache commons' DateUtils class. It has the static method isSameDay() which "Checks if two date objects are on the same day ignoring time."
static boolean isSameDay(Date date1, Date date2)
Use DateFormat to solve this problem:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
DateFormat dateFormat2 = new SimpleDateFormat("MM-dd-yyyy");
print(dateFormat.format(new Date()); // will print like 2014-02-20
print(dateFormat2.format(new Date()); // will print like 02-20-2014
I did as follows and it worked: (Current date without timestamp)
SimpleDateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy");
Date today = dateFormat.parse(dateFormat.format(new Date()));
DateFormat dateFormat = new SimpleDateFormat("MMMM dd yyyy");
java.util.Date date = new java.util.Date();
System.out.println("Current Date : " + dateFormat.format(date));
You can get by this date:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
print(dateFormat.format(new Date());
You could use
// Format a string containing a date.
import java.util.Calendar;
import java.util.GregorianCalendar;
import static java.util.Calendar.*;
Calendar c = GregorianCalendar.getInstance();
String s = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c);
// -> s == "Duke's Birthday: May 23, 1995"
Have a look at the Formatter API documentation.
The accepted answer by Jesper is correct but now outdated. The java.util.Date and .Calendar classes are notoriously troublesome. Avoid them.
java.time
Instead use the java.time framework, built into Java 8 and later, back-ported to Java 6 & 7 and further adapted to Android.
If you truly do not care about time-of-day and time zones, use LocalDate in the java.time framework ().
LocalDate localDate = LocalDate.of( 2014 , 5 , 6 );
Today
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
If no time zone is specified, the JVM implicitly applies its current default time zone. That default may change at any moment during runtime(!), so your results may vary. Better to specify your desired/expected time zone explicitly as an argument. If you want to use the JVM’s current default time zone, make your intention clear by calling ZoneId.systemDefault(). If critical, confirm the zone with your user.
Specify a proper time zone name in the format of Continent/Region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 2-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" ) ;
LocalDate today = LocalDate.now( z ) ;
If you want to use the JVM’s current default time zone, ask for it and pass as an argument. If omitted, the code becomes ambiguous to read in that we do not know for certain if you intended to use the default or if you, like so many programmers, were unaware of the issue.
ZoneId z = ZoneId.systemDefault() ; // Get JVM’s current default time zone.
LocalDate today = LocalDate.now( z ) ;
Moment
If you care about specific moments, specific points on the timeline, do not use LocalDate. If you care about the date as seen through the wall-clock time used by the people of a certain region, do not use LocalDate.
Be aware that if you have any chance of needing to deal with other time zones or UTC, this is the wrong way to go. Naïve programmers tend to think they do not need time zones when in fact they do.
Strings
Call toString to generate a string in standard ISO 8601 format.
String output = localDate.toString();
2014-05-06
For other formats, search Stack Overflow for DateTimeFormatter class.
Joda-Time
Though now supplanted by java.time, you can use the similar LocalDate class in the Joda-Time library (the inspiration for java.time).
LocalDate localDate = new LocalDate( 2014, 5, 6 );
Also you can use apache commons lib DateUtils.truncate():
Date now = new Date();
Date truncated = DateUtils.truncate(now, Calendar.DAY_OF_MONTH);
Time will be set to 00:00:00 so you can work with this date or print it formatted:
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(dateFormat.format(now); // 2010-05-11 11:32:47
System.out.println(dateFormat.format(truncated); // 2010-05-11 00:00:00
private static final DateFormat df1 = new SimpleDateFormat("yyyyMMdd");
private static Date NOW = new Date();
static {
try {
NOW = df1.parse(df1.format(new Date()));
} catch (ParseException e) {
e.printStackTrace();
}
}
I think this will work. Use Calendar to manipulate time fields (reset them to zero), then get the Date from the Calendar.
Calendar c = GregorianCalendar.getInstance();
c.clear( Calendar.HOUR_OF_DAY );
c.clear( Calendar.MINUTE );
c.clear( Calendar.SECOND );
c.clear( Calendar.MILLISECOND );
Date today = c.getTime();
Or do the opposite. Put the date you want to compare to in a calendar and compare calendar dates
Date compareToDate; // assume this is set before going in.
Calendar today = GregorianCalendar.getInstance();
Calendar compareTo = GregorianCalendar.getInstance();
compareTo.setTime( compareToDate );
if( today.get( Calendar.YEAR ) == compareTo.get( Calendar.YEAR ) &&
today.get( Calendar.DAY_OF_YEAR ) == compareTo.get( Calendar.DAY_OF_YEAR ) ) {
// They are the same day!
}
Here's an inelegant way of doing it quick without additional dependencies.
You could just use java.sql.Date, which extends java.util.Date although for comparisons you will have to compare the Strings.
java.sql.Date dt1 = new java.sql.Date(System.currentTimeMillis());
String dt1Text = dt1.toString();
System.out.println("Current Date1 : " + dt1Text);
Thread.sleep(2000);
java.sql.Date dt2 = new java.sql.Date(System.currentTimeMillis());
String dt2Text = dt2.toString();
System.out.println("Current Date2 : " + dt2Text);
boolean dateResult = dt1.equals(dt2);
System.out.println("Date comparison is " + dateResult);
boolean stringResult = dt1Text.equals(dt2Text);
System.out.println("String comparison is " + stringResult);
Output:
Current Date1 : 2010-05-10
Current Date2 : 2010-05-10
Date comparison is false
String comparison is true
If you really want to use a Date instead for a Calendar for comparison, this is the shortest piece of code you could use:
Calendar c = Calendar.getInstance();
Date d = new GregorianCalendar(c.get(Calendar.YEAR),
c.get(Calendar.MONTH),
c.get(Calendar.DAY_OF_MONTH)).getTime();
This way you make sure the hours/minute/second/millisecond values are blank.
I did as follows and it worked:
calendar1.set(Calendar.HOUR_OF_DAY, 0);
calendar1.set(Calendar.AM_PM, 0);
calendar1.set(Calendar.HOUR, 0);
calendar1.set(Calendar.MINUTE, 0);
calendar1.set(Calendar.SECOND, 0);
calendar1.set(Calendar.MILLISECOND, 0);
Date date1 = calendar1.getTime(); // Convert it to date
Do this for other instances to which you want to compare. This logic worked for me; I had to compare the dates whether they are equal or not, but you can do different comparisons (before, after, equals, etc.)
I was looking for the same solution and the following worked for me.
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 0);
calendar.clear(Calendar.HOUR);
calendar.clear(Calendar.MINUTE);
calendar.clear(Calendar.SECOND);
calendar.clear(Calendar.MILLISECOND);
Date today = calendar.getTime();
Please note that I am using calendar.set(Calendar.HOUR_OF_DAY, 0) for HOUR_OF_DAY instead of using the clear method, because it is suggested in Calendar.clear method's javadocs as the following
The HOUR_OF_DAY, HOUR and AM_PM fields are handled independently and
the the resolution rule for the time of day is applied. Clearing one
of the fields doesn't reset the hour of day value of this Calendar.
Use set(Calendar.HOUR_OF_DAY, 0) to reset the hour value.
With the above posted solution I get output as
Wed Sep 11 00:00:00 EDT 2013
Using clear method for HOUR_OF_DAY resets hour at 12 when executing after 12PM or 00 when executing before 12PM.
Here is my code for get only date:
Calendar c=Calendar.getInstance();
DateFormat dm = new SimpleDateFormat("dd/MM/yyyy");
java.util.Date date = new java.util.Date();
System.out.println("current date is : " + dm.format(date));
Here is full Example of it.But you have to cast Sting back to Date.
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
//TODO OutPut should LIKE in this format MM dd yyyy HH:mm:ss.SSSSSS
public class TestDateExample {
public static void main(String args[]) throws ParseException {
SimpleDateFormat changeFormat = new SimpleDateFormat("MM dd yyyy HH:mm:ss.SSSSSS");
Date thisDate = new Date();//changeFormat.parse("10 07 2012");
System.out.println("Current Date : " + thisDate);
changeFormat.format(thisDate);
System.out.println("----------------------------");
System.out.println("After applying formating :");
String strDateOutput = changeFormat.format(thisDate);
System.out.println(strDateOutput);
}
}