How to save iso8601 Date in Java? - java

I need to save the current Date + 7 days in iso8601 format as following:
20161107T12:00:00+0000
Where the part after the "T" is fixed.
I tried the following:
Calendar exDate1 = Calendar.getInstance();
exDate1.add(Calendar.DATE , 7);
Date Date1 = exDate1.getTime();
SimpleDateFormat sdf = new SimpleDateFormat("YYYYMMDD");
String Date = sdf.format(Date1 + "T12:00:00+0000");
With no success.

Another way is using the new java.time-API in Java-8:
String result =
DateTimeFormatter.BASIC_ISO_DATE.format(
LocalDate.now(ZoneOffset.UTC).plusDays(7)
) + "T12:00:00+0000";
System.out.println(result); // 20161114T12:00:00+0000
Update due to your choice of timezone offset:
You tried to implicitly use the system timezone to determine the current local time but apply a fixed offset of UTC+0000. This is an inconsistent combination. If you apply such a zero offset then you should also determine the current date according to UTC+0000, not in your system timezone (ZoneId.systemDefault()).
The proposal of editor #Nim
Alternatively - the string above may not have the correct offset:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd'T'HH:mm:ssZ");
String date = LocalDate.now().plusDays(7).atTime(12, 0).atZone(ZoneId.systemDefault()).format(formatter);
would yield the result:
20161114T12:00:00+0100
which is probably not what you want. I also try to avoid the expression LocalDate.now() without any arguments because it hides the dependency on the system timezone.

use this 'yyyyMMdd'pattern
Calendar currentDate = Calendar.getInstance();
currentDate.add(Calendar.DATE, 7);
Date date = currentDate.getTime();
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
String formattedDate = sdf.format(date).concat("T12:00:00+0000");

Related

my Date Util formatter does not return my intended date format need help, [duplicate]

How to convert calendar date to yyyy-MM-dd format.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
Date date = cal.getTime();
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
String date1 = format1.format(date);
Date inActiveDate = null;
try {
inActiveDate = format1.parse(date1);
} catch (ParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
This will produce inActiveDate = Wed Sep 26 00:00:00 IST 2012. But what I need is 2012-09-26. My purpose is to compare this date with another date in my database using Hibernate criteria. So I need the date object in yyyy-MM-dd format.
A Java Date is a container for the number of milliseconds since January 1, 1970, 00:00:00 GMT.
When you use something like System.out.println(date), Java uses Date.toString() to print the contents.
The only way to change it is to override Date and provide your own implementation of Date.toString(). Now before you fire up your IDE and try this, I wouldn't; it will only complicate matters. You are better off formatting the date to the format you want to use (or display).
Java 8+
LocalDateTime ldt = LocalDateTime.now().plusDays(1);
DateTimeFormatter formmat1 = DateTimeFormatter.ofPattern("yyyy-MM-dd", Locale.ENGLISH);
System.out.println(ldt);
// Output "2018-05-12T17:21:53.658"
String formatter = formmat1.format(ldt);
System.out.println(formatter);
// 2018-05-12
Prior to Java 8
You should be making use of the ThreeTen Backport
The following is maintained for historical purposes (as the original answer)
What you can do, is format the date.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(cal.getTime());
// Output "Wed Sep 26 14:23:28 EST 2012"
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
// Output "2012-09-26"
System.out.println(format1.parse(formatted));
// Output "Wed Sep 26 00:00:00 EST 2012"
These are actually the same date, represented differently.
Your code is wrong. No point of parsing date and keep that as Date object.
You can format the calender date object when you want to display and keep that as a string.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
Date date = cal.getTime();
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
String inActiveDate = null;
try {
inActiveDate = format1.format(date);
System.out.println(inActiveDate );
} catch (ParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
java.time
The answer by MadProgrammer is correct, especially the tip about Joda-Time. The successor to Joda-Time is now built into Java 8 as the new java.time package. Here's example code in Java 8.
When working with date-time (as opposed to local date), the time zone in critical. The day-of-month depends on the time zone. For example, the India time zone is +05:30 (five and a half hours ahead of UTC), while France is only one hour ahead. So a moment in a new day in India has one date while the same moment in France has “yesterday’s” date. Creating string output lacking any time zone or offset information is creating ambiguity. You asked for YYYY-MM-DD output so I provided, but I don't recommend it. Instead of ISO_LOCAL_DATE I would have used ISO_DATE to get this output: 2014-02-25+05:30
ZoneId zoneId = ZoneId.of( "Asia/Kolkata" );
ZonedDateTime zonedDateTime = ZonedDateTime.now( zoneId );
DateTimeFormatter formatterOutput = DateTimeFormatter.ISO_LOCAL_DATE; // Caution: The "LOCAL" part means we are losing time zone information, creating ambiguity.
String output = formatterOutput.format( zonedDateTime );
Dump to console…
System.out.println( "zonedDateTime: " + zonedDateTime );
System.out.println( "output: " + output );
When run…
zonedDateTime: 2014-02-25T14:22:20.919+05:30[Asia/Kolkata]
output: 2014-02-25
Joda-Time
Similar code using the Joda-Time library, the precursor to java.time.
DateTimeZone zone = new DateTimeZone( "Asia/Kolkata" );
DateTime dateTime = DateTime.now( zone );
DateTimeFormatter formatter = ISODateTimeFormat.date();
String output = formatter.print( dateTime );
ISO 8601
By the way, that format of your input string is a standard format, one of several handy date-time string formats defined by ISO 8601.
Both Joda-Time and java.time use ISO 8601 formats by default when parsing and generating string representations of various date-time values.
java.util.Date object can't represent date in custom format instead you've to use SimpleDateFormat.format method that returns string.
String myString=format1.format(date);
public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
cal.set(year, month, date);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy MM dd");
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
}
In order to parse a java.util.Date object you have to convert it to String first using your own format.
inActiveDate = format1.parse( format1.format(date) );
But I believe you are being redundant here.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 7);
Date date = c.getTime();
SimpleDateFormat ft = new SimpleDateFormat("MM-dd-YYYY");
JOptionPane.showMessageDialog(null, ft.format(date));
This will display your date + 7 days in month, day and year format in a JOption window pane.
public static String ThisWeekStartDate(WebDriver driver) {
Calendar c = Calendar.getInstance();
//ensure the method works within current month
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
System.out.println("Before Start Date " + c.getTime());
Date date = c.getTime();
SimpleDateFormat dfDate = new SimpleDateFormat("dd MMM yyyy hh.mm a");
String CurrentDate = dfDate.format(date);
System.out.println("Start Date " + CurrentDate);
return CurrentDate;
}
public static String ThisWeekEndDate(WebDriver driver) {
Calendar c = Calendar.getInstance();
//ensure the method works within current month
c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
System.out.println("Before End Date " + c.getTime());
Date date = c.getTime();
SimpleDateFormat dfDate = new SimpleDateFormat("dd MMM yyyy hh.mm a");
String CurrentDate = dfDate.format(date);
System.out.println("End Date " + CurrentDate);
return CurrentDate;
}
I found this code where date is compared in a format to compare with date field in database...may be this might be helpful to you...
When you convert the string to date using simpledateformat, it is hard to compare with the Date field in mysql databases.
So convert the java string date in the format using select STR_to_DATE('yourdate','%m/%d/%Y') --> in this format, then you will get the exact date format of mysql date field.
http://javainfinite.com/java/java-convert-string-to-date-and-compare/
My answer is for kotlin language.
You can use SimpleDateFormat to achieve the result:
val date = Date(timeInSec)
val formattedDate = SimpleDateFormat("yyyy-MM-dd", Locale("IN")).format(date)
for details click here.
OR
Use Calendar to do it for you:
val dateObject = Date(timeInMillis)
val calendarInstance = Calendar.getInstance()
calendarInstance.time = dateObject
val date = "${calendarInstance.get(Calendar.YEAR)}-${calendarInstance.get(Calendar.MONTH)}-${calendarInstance.get(Calendar.DATE)}"
For more details check this answer.
I don't know about y'all, but I always want this stuff as a one-liner. The other answers are fine and dandy and work great, but here is it condensed to a single line. Now you can hold less lines of code in your mind :-).
Here is the one Liner:
String currentDate = new SimpleDateFormat("yyyy-MM-dd").format(new Date());

How to do subtraction from a particular date using Java [duplicate]

This question already has answers here:
Calendar date to yyyy-MM-dd format in java
(11 answers)
Closed 4 years ago.
I am encountering an issue which is related to Java Date Function.
I'm getting the date from Application (example: 6/5/18) which is in MM/DD/YY format. Now I need to do -2 from the date. I know how to do -2 from current system date using calendar object (see the below code).
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE,-2);
DateFormat dateFormat = new SimpleDateFormat("MM/dd/yy");
String PastDate = dateFormat.format(cal.getTime());
info("Date is displayed as : "+ PastDate );
I'm not able to put the date which I'm getting from Application in this format. Can someone please help me? (Any other way to do it would also be fine)
I suggest you to use Java 8 compatible Date and Time types.
If you use java.time.LocalDate then this is the solution:
LocalDate.now().minusDays(2)
From your question, it seems that you have the challenge in dealing with formatting, and then doing the subtraction.
I would recommend Java Date and Time Apis for this purpose, using a formatter.
A junit method to achieve your requirement is given below
#Test
public void testDateFormatUsingJava8() {
CharSequence inputdateTxt = "6/5/18";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("M/d/yy");
LocalDate inputDate = LocalDate.parse(inputdateTxt, formatter);
System.out.println(inputDate.minusDays(2L).format(formatter));
}
#Test
public void testDateCalenderUsingStringSplit() {
String inputdateTxt = "6/5/18";
String[] dateComponenets = inputdateTxt.split("//");
Calendar cal = Calendar.getInstance();
//Know where are the year month and date are stored.
cal.set(Integer.parseInt(dateComponenets[2]), Integer.parseInt(dateComponenets[0]), Integer.parseInt(dateComponenets[2]) );
cal.add(Calendar.DATE,-2);
DateFormat dateFormat = new SimpleDateFormat("M/d/yy");
String pastDate = dateFormat.format(cal.getTime());
System.out.println("Date is displayed as : "+ pastDate );
}
#Test
public void testDateCalenderUsingJavaUtilDateApi() throws ParseException {
String inputdateTxt = "6/5/18";
DateFormat dateFormat = new SimpleDateFormat("M/d/yy");
Date date = dateFormat.parse(inputdateTxt);
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.DATE,-2);
String pastDate = dateFormat.format(cal.getTime());
System.out.println("Date is displayed as : "+ pastDate );
The reason why I use "M/d/yy" is because your question does not pad the date and month fields in the input date with a zero. If there is a guarantee that you receive a padded value in the date and month field, using "MM/dd/yy" is suggested.
See the following answer for your reference :
DateTimeFormatterSupport for Single Digit Values
EDIT: considering the limitation to not use Java 8 Date Time APIs, I have added two other alternatives to solve the problem. The OP is free to choose any one of the solutions. Kept the Java 8 solution intact for information purposes.
Calendar cal = Calendar.getInstance();
cal.set(2018, 5, 6); // add this, setting data from the value you parsed
cal.add(Calendar.DATE,-2);
DateFormat dateFormat = new SimpleDateFormat("MM/dd/yy");
String PastDate = dateFormat.format(cal.getTime());
System.out.println("Date is displayed as : "+ PastDate);

Change format date in Java does not work correctly [duplicate]

How to convert calendar date to yyyy-MM-dd format.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
Date date = cal.getTime();
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
String date1 = format1.format(date);
Date inActiveDate = null;
try {
inActiveDate = format1.parse(date1);
} catch (ParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
This will produce inActiveDate = Wed Sep 26 00:00:00 IST 2012. But what I need is 2012-09-26. My purpose is to compare this date with another date in my database using Hibernate criteria. So I need the date object in yyyy-MM-dd format.
A Java Date is a container for the number of milliseconds since January 1, 1970, 00:00:00 GMT.
When you use something like System.out.println(date), Java uses Date.toString() to print the contents.
The only way to change it is to override Date and provide your own implementation of Date.toString(). Now before you fire up your IDE and try this, I wouldn't; it will only complicate matters. You are better off formatting the date to the format you want to use (or display).
Java 8+
LocalDateTime ldt = LocalDateTime.now().plusDays(1);
DateTimeFormatter formmat1 = DateTimeFormatter.ofPattern("yyyy-MM-dd", Locale.ENGLISH);
System.out.println(ldt);
// Output "2018-05-12T17:21:53.658"
String formatter = formmat1.format(ldt);
System.out.println(formatter);
// 2018-05-12
Prior to Java 8
You should be making use of the ThreeTen Backport
The following is maintained for historical purposes (as the original answer)
What you can do, is format the date.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
System.out.println(cal.getTime());
// Output "Wed Sep 26 14:23:28 EST 2012"
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
// Output "2012-09-26"
System.out.println(format1.parse(formatted));
// Output "Wed Sep 26 00:00:00 EST 2012"
These are actually the same date, represented differently.
Your code is wrong. No point of parsing date and keep that as Date object.
You can format the calender date object when you want to display and keep that as a string.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 1);
Date date = cal.getTime();
SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
String inActiveDate = null;
try {
inActiveDate = format1.format(date);
System.out.println(inActiveDate );
} catch (ParseException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
java.time
The answer by MadProgrammer is correct, especially the tip about Joda-Time. The successor to Joda-Time is now built into Java 8 as the new java.time package. Here's example code in Java 8.
When working with date-time (as opposed to local date), the time zone in critical. The day-of-month depends on the time zone. For example, the India time zone is +05:30 (five and a half hours ahead of UTC), while France is only one hour ahead. So a moment in a new day in India has one date while the same moment in France has “yesterday’s” date. Creating string output lacking any time zone or offset information is creating ambiguity. You asked for YYYY-MM-DD output so I provided, but I don't recommend it. Instead of ISO_LOCAL_DATE I would have used ISO_DATE to get this output: 2014-02-25+05:30
ZoneId zoneId = ZoneId.of( "Asia/Kolkata" );
ZonedDateTime zonedDateTime = ZonedDateTime.now( zoneId );
DateTimeFormatter formatterOutput = DateTimeFormatter.ISO_LOCAL_DATE; // Caution: The "LOCAL" part means we are losing time zone information, creating ambiguity.
String output = formatterOutput.format( zonedDateTime );
Dump to console…
System.out.println( "zonedDateTime: " + zonedDateTime );
System.out.println( "output: " + output );
When run…
zonedDateTime: 2014-02-25T14:22:20.919+05:30[Asia/Kolkata]
output: 2014-02-25
Joda-Time
Similar code using the Joda-Time library, the precursor to java.time.
DateTimeZone zone = new DateTimeZone( "Asia/Kolkata" );
DateTime dateTime = DateTime.now( zone );
DateTimeFormatter formatter = ISODateTimeFormat.date();
String output = formatter.print( dateTime );
ISO 8601
By the way, that format of your input string is a standard format, one of several handy date-time string formats defined by ISO 8601.
Both Joda-Time and java.time use ISO 8601 formats by default when parsing and generating string representations of various date-time values.
java.util.Date object can't represent date in custom format instead you've to use SimpleDateFormat.format method that returns string.
String myString=format1.format(date);
public static void main(String[] args) {
Calendar cal = Calendar.getInstance();
cal.set(year, month, date);
SimpleDateFormat format1 = new SimpleDateFormat("yyyy MM dd");
String formatted = format1.format(cal.getTime());
System.out.println(formatted);
}
In order to parse a java.util.Date object you have to convert it to String first using your own format.
inActiveDate = format1.parse( format1.format(date) );
But I believe you are being redundant here.
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, 7);
Date date = c.getTime();
SimpleDateFormat ft = new SimpleDateFormat("MM-dd-YYYY");
JOptionPane.showMessageDialog(null, ft.format(date));
This will display your date + 7 days in month, day and year format in a JOption window pane.
public static String ThisWeekStartDate(WebDriver driver) {
Calendar c = Calendar.getInstance();
//ensure the method works within current month
c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
System.out.println("Before Start Date " + c.getTime());
Date date = c.getTime();
SimpleDateFormat dfDate = new SimpleDateFormat("dd MMM yyyy hh.mm a");
String CurrentDate = dfDate.format(date);
System.out.println("Start Date " + CurrentDate);
return CurrentDate;
}
public static String ThisWeekEndDate(WebDriver driver) {
Calendar c = Calendar.getInstance();
//ensure the method works within current month
c.set(Calendar.DAY_OF_WEEK, Calendar.SATURDAY);
System.out.println("Before End Date " + c.getTime());
Date date = c.getTime();
SimpleDateFormat dfDate = new SimpleDateFormat("dd MMM yyyy hh.mm a");
String CurrentDate = dfDate.format(date);
System.out.println("End Date " + CurrentDate);
return CurrentDate;
}
I found this code where date is compared in a format to compare with date field in database...may be this might be helpful to you...
When you convert the string to date using simpledateformat, it is hard to compare with the Date field in mysql databases.
So convert the java string date in the format using select STR_to_DATE('yourdate','%m/%d/%Y') --> in this format, then you will get the exact date format of mysql date field.
http://javainfinite.com/java/java-convert-string-to-date-and-compare/
My answer is for kotlin language.
You can use SimpleDateFormat to achieve the result:
val date = Date(timeInSec)
val formattedDate = SimpleDateFormat("yyyy-MM-dd", Locale("IN")).format(date)
for details click here.
OR
Use Calendar to do it for you:
val dateObject = Date(timeInMillis)
val calendarInstance = Calendar.getInstance()
calendarInstance.time = dateObject
val date = "${calendarInstance.get(Calendar.YEAR)}-${calendarInstance.get(Calendar.MONTH)}-${calendarInstance.get(Calendar.DATE)}"
For more details check this answer.
I don't know about y'all, but I always want this stuff as a one-liner. The other answers are fine and dandy and work great, but here is it condensed to a single line. Now you can hold less lines of code in your mind :-).
Here is the one Liner:
String currentDate = new SimpleDateFormat("yyyy-MM-dd").format(new Date());

How to add current time to a previous date in java?

I was trying to add current time into previous date. But it was adding in current date with time not with previous date.
see my bellow code:
Date startUserDate = ;//this is my previous date object;
startUserDate.setTime(new Date().getTime());// here i'm trying to add current time in previous date.
System.out.println("current time with previous Date :"+startUserDate);
In previous date there is no time and i want to add current time in previous date.I can do this, please help me out.
Use calendar object
Get instance of calendar object and set your past time to it
Date startUserDate = ;
Calendar calendar = Calendar.getInstance();
calendar.settime(startUserDate);
Create new calendar instance
Calendar cal = Calendar.getInstance();
cal.settime(new Date());
format the date to get string representation of time of current date
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
String currentdate = sdf.format(cal.getTime());
split that string to get hour minute and second object
String hh = expiry.split(":")[0];
String mm = expiry.split(":")[1];
String ss = expiry.split(":")[2];
add it to the previous calendar object
calendar .add(Calendar.HOUR_OF_DAY, hh);
calendar .add(Calendar.MINUTE, mm);
calendar .add(Calendar.SECOND, ss);
this date will have current time added to your date
Date newDate = calendar.getTime;
Use Calendar:
first set the date/time of the first calendar object to the old date
object use as second Calendar object to set the current time on the
first calendar object then convert it back to date
as follow:
//E.g. for startUserDate
Date startUserDate = new Date(System.currentTimeMillis() - (24L * 60L * 60L * 1000L) - (60L * 60L * 1000L));//minus 1 day and 1 hour
Calendar calDateThen = Calendar.getInstance();
Calendar calTimeNow = Calendar.getInstance();
calDateThen.setTime(startUserDate);
calDateThen.set(Calendar.HOUR_OF_DAY, calTimeNow.get(Calendar.HOUR_OF_DAY));
calDateThen.set(Calendar.MINUTE, calTimeNow.get(Calendar.MINUTE));
calDateThen.set(Calendar.SECOND, calTimeNow.get(Calendar.SECOND));
startUserDate = calDateThen.getTime();
System.out.println(startUserDate);
The second Calendar object calTimeNow can be replaced with Calendar.getInstance() where it is used.
You can do it using DateFormat and String, here's the solution that you need:
Code:
DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
String timeString = df.format(new Date()).substring(10); // 10 is the beginIndex of time here
DateFormat df2 = new SimpleDateFormat("MM/dd/yyyy");
String startUserDateString = df2.format(startUserDate);
startUserDateString = startUserDateString+" "+timeString;
// you will get this format "MM/dd/yyyy HH:mm:ss"
//then parse the new date here
startUserDate = df.parse(startUserDateString);
Explanation:
Just convert the current date to a string and then extract the time from it using .substring() method, then convert your userDate to a string concatenate the taken time String to it and finally parse this date to get what you need.
Example:
You can see it working in this ideone DEMO.
Which takes 02/20/2002 in input and returns 02/20/2002 04:36:14 as result.
java.time
I recommend that you use java.time, the modern Java date and time API, for your date and time work.
ZoneId zone = ZoneId.systemDefault();
LocalDate somePreviousDate = LocalDate.of(2018, Month.NOVEMBER, 22);
LocalTime timeOfDayNow = LocalTime.now(zone);
LocalDateTime dateTime = somePreviousDate.atTime(timeOfDayNow);
System.out.println(dateTime);
When I ran the code just now — 16:25 in my time zone — I got this output:
2018-11-22T16:25:53.253892
If you’ve got an old-fashioned Date object, start by converting to a modern Instant and perform further conversion from there:
Date somePreviousDate = new Date(1_555_555_555_555L);
LocalDate date = somePreviousDate.toInstant().atZone(zone).toLocalDate();
LocalTime timeOfDayNow = LocalTime.now(zone);
LocalDateTime dateTime = date.atTime(timeOfDayNow);
2019-04-18T16:25:53.277947
If conversely you need the result as an old-fashioned Date, also convert over Instant:
Instant i = dateTime.atZone(zone).toInstant();
Date oldfasionedDate = Date.from(i);
System.out.println(oldfasionedDate);
Thu Nov 22 16:25:53 CET 2018
Link
Oracle tutorial: Date Time explaining how to use java.time.
The getTime method returns the number of milliseconds since 1970/01/01 so to get the time portion of the date you can either use a Calendar object or simply use modula arithmetic (using the above milliseconds value and the MAX millseconds in a day) to extract the time portion of the Date.
Then when you have the time you need to add it to the second date,
but seriously, use http://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html
and use things like get (HOUR) and get (MINUTE) etc. which then you can use with set (HOUR, val)
You need to use Calendar class to perform addition to Dateobject. Date's setTime() will set that time in Date object but not add i.e it will overwrite previous date. new Date().getTime() will not return only time portion but time since Epoch. Also, how did you manipulated , startUserDate to not have any time (I mean , was it via Calendar or Formatter) ?
See Answer , Time Portion of Date to calculate only time portion,
long MILLIS_PER_DAY = 24 * 60 * 60 * 1000;
Date now = Calendar.getInstance().getTime();
long timePortion = now.getTime() % MILLIS_PER_DAY;
then you can use something like, cal.add(Calendar.MILLISECOND, (int)timePortion); where cal is Calendar object corresponding to your startUserDate in your code.
Calendar calendar = Calendar.getInstance();
calendar.setTime(startUserDate );
//new date for current time
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
String currentdate = sdf.format(new Date());
String hhStr = currentdate.split(":")[0];
String mmStr = currentdate.split(":")[1];
String ssStr = currentdate.split(":")[2];
Integer hh = 0;
Integer mm = 0;
Integer ss = 0;
try {
hh = Integer.parseInt(hhStr);
mm = Integer.parseInt(mmStr);
ss = Integer.parseInt(ssStr);
}catch(Exception e) {e.printStackTrace();}
calendar.set(Calendar.HOUR_OF_DAY, hh);
calendar.set(Calendar.MINUTE, mm);
calendar.set(Calendar.SECOND, ss);
startUserDate = calendar.getTime();

How to get particular parts of a DateTime object?

I have a DateTime object DT which stores current time. When I print DT, I want it to only print the time part, ie HH-MM-SS (H = hours, M = minutes, S = seconds) and ignore the date part.
How can I do this ? For that matter, is it even possible to create a date time object which will only contain HH-MM-SS and nothing related to date ? If that is true, then I can simply print it instead of extracting the HH-MM-SS part.
Thanks.
If you only want the time, you should use a LocalTime instead of a DateTime. You can use DateTime.toLocalTime() to get the time part of an existing DateTime.
If you actually want to keep the DateTime but only reveal the time part when formatting, you can create a DateTimeFormatter with a pattern which only includes the time parts, but I'd usually consider this a design smell.
You can use Java date formatter which is in java.util.Date package.
Like :
Date todaysDate = new java.util.Date();
1. // Formatting date into yyyy-MM-dd HH:mm:ss e.g 2008-10-10 11:21:10
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String formattedDate = formatter.format(todaysDate);
2. // Formatting date into yyyy-MM-dd e.g 2008-10-10
formatter = new SimpleDateFormat("yyyy-MM-dd");
formattedDate = formatter.format(todaysDate);
3. // Formatting date into MM/dd/yyyy e.g 10/10/2008
formatter = new SimpleDateFormat("MM/dd/yyyy");
formattedDate = formatter.format(todaysDate);
With Java you can do it like this
Date obj = new Date() ;
System.out.println(new SimpleDateFormat("hh:mm:ss").format(obj)) ;
but it could be an expensive call.
But jodatime gives LocalTime which you can try out.

Categories