Develop Reference

How to print date string with ISO8601 format?

Please help me to print my date in below format
Example: 2020-08-05T16:17:10,777
I tried with below date converter but it is not giving the output that I want.
SimpleDateFormat sdf;
sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSXXX");
String text = sdf.format(requestTime);
loggdata.append(REQUEST_TIME + requestDate);
I got date printed like "2020-08-20T06:26:09.003763Z". Date is in UTC tomezone and format is different.
I can see many question and answers here in stackoverflow. But here in my case I need exactly this format 2020-08-05T16:17:10,777 see the last portion ",777".
Also I need to display the time in local timezone

Found a solution for the same. I have used "LocalDateTime" for the same.
LocalDateTime now = LocalDateTime.now();
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss,SSS");
String dateInString= now.format(formatter);
It displayed date like this "2020-08-20T21:18:56,321"

Date value converted from Calendar outputs different format than String [duplicate]

I have the following scenario :
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
System.out.println(dateFormat.parse("31/05/2011"));
gives an output
Tue May 31 00:00:00 SGT 2011
but I want the output to be
31/05/2011
I need to use parse here because the dates need to be sorted as Dates and not as String.
Any ideas ??

How about:
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
System.out.println(dateFormat.format(dateFormat.parse("31/05/2011")));
> 31/05/2011

You need to go through SimpleDateFormat.format in order to format the date as a string.
Here's an example that goes from String -> Date -> String.
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
Date date = dateFormat.parse("31/05/2011");
System.out.println(dateFormat.format(date)); // prints 31/05/2011
// ^^^^^^

Use the SimpleDateFormat.format
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
Date date = new Date();
String sDate= sdf.format(date);

You can use simple date format in Java using the code below
SimpleDateFormat simpledatafo = new SimpleDateFormat("dd/MM/yyyy");
Date newDate = new Date();
String expectedDate= simpledatafo.format(newDate);

It makes no sense, but:
System.out.println(dateFormat.format(dateFormat.parse("31/05/2011")))
SimpleDateFormat.parse() = // parse Date from String
SimpleDateFormat.format() = // format Date into String

If you want to simply output a date, just use the following:
System.out.printf("Date: %1$te/%1$tm/%1$tY at %1$tH:%1$tM:%1$tS%n", new Date());
As seen here. Or if you want to get the value into a String (for SQL building, for example) you can use:
String formattedDate = String.format("%1$te/%1$tm/%1$tY", new Date());
You can also customize your output by following the Java API on Date/Time conversions.

java.time
Here’s the modern answer.
DateTimeFormatter sourceFormatter = DateTimeFormatter.ofPattern("dd/MM/uuuu");
DateTimeFormatter displayFormatter = DateTimeFormatter
.ofLocalizedDate(FormatStyle.SHORT)
.withLocale(Locale.forLanguageTag("zh-SG"));
String dateString = "31/05/2011";
LocalDate date = LocalDate.parse(dateString, sourceFormatter);
System.out.println(date.format(displayFormatter));
Output from this snippet is:
31/05/11
See if you can live with the 2-digit year. Or use FormatStyle.MEDIUM to obtain 2011年5月31日. I recommend you use Java’s built-in date and time formats when you can. It’s easier and lends itself very well to internationalization.
If you need the exact format you gave, just use the source formatter as display formatter too:
System.out.println(date.format(sourceFormatter));
31/05/2011
I recommend you don’t use SimpleDateFormat. It’s notoriously troublesome and long outdated. Instead I use java.time, the modern Java date and time API.
To obtain a specific format you need to format the parsed date back into a string. Netiher an old-fashioned Date nor a modern LocalDatecan have a format in it.
Link: Oracle tutorial: Date Time explaining how to use java.time.

You already has this (that's what you entered) parse will parse a date into a giving format and print the full date object (toString).

This will help you.
DateFormat df = new SimpleDateFormat("dd/MM/yyyy");
print (df.format(new Date());

I had something like this, my suggestion would be to use java for things like this, don't put in boilerplate code

This looks more compact. Finishes in a single line.
import org.apache.commons.lang3.time.DateFormatUtils;
System.out.println(DateFormatUtils.format(newDate, "yyyy-MM-dd HH:mm:ss"));

Oracle Date Format change to yyyy-MM-dd hh:mm:ss

I have date saletime as 2/25/14 22:06 I want to store it in oracle table in the yyyy-MM-dd hh:mm:ss. So I wrote following java code
Date saleTime = sale.getSaleTime();
logger.info("DateTime is "+saleTime);
SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date saleTimeNorm = formatter.parse(formatter.format(saleTime));
logger.info("DateTime after Formating "+saleTimeNorm);
Timestamp oracleDate = new Timestamp(saleTimeNorm.getTime());
logger.info("New Format Inserting :"+oracleDate);
sale.setSaleTime(oracleDate);
But this seems to be giving :0014-02-25 22:06:00.0
Any suggestions ?

Your getSaleTime() method somehow regards "14" as a four-digit year, and returns the year 14.
After you have executed getSaleTime(), you already have a Date variable; there is no need (and no use) in converting it to a different output format and re-parsing the result. The Date you get from the calls to format() and parse() will be the same one you started with.
You can create your Timestamp using getTime() on the result of the call to getSaleTime(). That will be correct once you change getSaleTime() so that it returns the date in the correct year.

Something must be wrong in your sale.getSaleTime() method. Because the following code working as needed.
Date saleTime = Calendar.getInstance().getTime();
SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date saleTimeNorm = formatter.parse(formatter.format(saleTime));
Timestamp oracleDate = new Timestamp(saleTimeNorm.getTime());
System.out.println(oracleDate);
//2014-05-13 03:58:53.0

SimpleDateFormat parsing date string incorrectly

I'm trying to parse a String into a Date and then format that Date into a different String format for outputting.
My date formatting code is as follows:
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat dateParser = new SimpleDateFormat("d/M/yyyy h:m:s a");
String formattedDocumentDate = dateFormatter.format(dateParser.parse(sysObj.getString("document_date")));
The result of sysObj.getString("document_date") is 1/31/2013 12:00:01 AM. And when I check the value of formattedDocumentDate I get 01/07/2015.
Any help is much appreciated.

You are parsing days 31 as months. SimpleDateFormat tries to give you a valid date. Therefore It adds to 1/0/2013 31 months. This is 2 years and 7 month. So you get your result 01/07/2015. So SimpleDateFormat works correct.
One solution for you is to change your date pattern to M/d/yyyy h:m:s a or your input data.
To avoid these tries you have to switch off SimpleDateFormat lenient mode. Then you will get an exception if the format does not fit.

It looks like your input format is actually months first, then days. So should be "MM/dd/yyyy".
So:
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd/M/yyyy");
SimpleDateFormat dateParser = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a");
String formattedDocumentDate = dateFormatter.format(dateParser.parse(sysObj.getString("document_date")));

Another example like this
SimpleDateFormat sdfInput = new SimpleDateFormat("yyyyMMdd");
System.out.println("date is:"+new java.sql.Date( sdfInput.parse("20164129").getTime() ));
Output is: 2019-05-29
I expect to throw parse exception but not (41)is not a valid month value.
on the other hand if I gave 20170229, system can recognize the February of 2017 doesn't have a lap year and return 2017-03-01 interesting.

Getting formatted date in date format rather than String

I'm running the program written below, but instead of printing in mm/dd/yyyy hh:mm format it prints in the normal date format(ie. Day Date and time)
SimpleDateFormat sdf = new SimpleDateFormat("mm/dd/yyyy hh:mm");
Date date = sdf.parse(sdf.format(Calendar.getInstance().getTime()));
The reason i'm doing this is because the existing method accepts parameters in Date format, so i need to send the above mentioned date object to it.
Please point out the mistake or suggest some other alternative.
Thanks

Date objects don't have a format. The Date class is a wrapper around a single long, the number of milliseconds since the epoch. You can't "format" a Date, only a String. Pass around a Date/Calendar internally, and format it whenever you need to display it, log it, or otherwise return it to the user.

Change the format to MM/dd/yyyy. Month is denoted by capital M.
Check below URL for valid formats
http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Your formatter works quite fine (apart from the mm vs. MM bug). You get a formatted string from the date and then create a copy from your date by parsing the formatted string:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm");
Date now = Calendar.getInstance().getTime();
String formattedNow = sdf.format(now); // == "09/24/2013 01:59"
Date now2 = sdf.parse(formattedNow); // == now