Want Current Date and Time in "Dd/Mm/Yyyy Hh:Mm:Ss.Ss" Format

Java How to get date format : dd/MM/yyyy HH:mm:ss.SS” with Date variable

If you want to store the hours, minutes and seconds, you have to use DateTime or LocalDateTime type instead of java.util.Date. Date only stores the year, month and day.

Then, you can use a formatter. For example:

public DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm:ss.SS");

Check format of dateTime matches custom format (dd/MM/yyyy HH:mm:ss) - Java

I’d go for this in the following way:

private static final DateTimeFormatter PARSER
        = DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm:ss", Locale.ROOT);

@Test
public void correctFormatReceived() {
    String dateTime = "10/18/2021 17:18:53"; // get from JSON
    LocalDateTime.parse(dateTime, PARSER);
}

LocalDateTime.parse() will throw a DateTimeParseException if the format is incorrect, which JUnit or your test runner will then report.

If you want strict validation of the date and time value (detect if they send February 29 in a non-leap year, for example), specify so on the formatter:

private static final DateTimeFormatter PARSER
        = DateTimeFormatter.ofPattern("dd/MM/yyyy HH:mm:ss", Locale.ROOT)
                .withResolverStyle(ResolverStyle.STRICT);

If you want to distinguish clearer between an incorrect format and your test failing to run to completion, catch the exception and declare a test failure:

try {
    LocalDateTime.parse(dateTime, PARSER);
} catch (DateTimeParseException dtpe) {
    Assert.fail(dtpe.toString());
}

What went wrong in your test?

As others have said in comments, in Java, a String can never be equal to a LocalDateTime. So your Assert.assertEquals(parsedDateTime, dateTime); would fail under all circumstances. Also, being able to parse the string at all is enough to determine that the specified format is as expected; so in your test, you don’t need to test for any equality.

get current date time in yyyy-MM-dd hh.mm.ss format

You aren't parsing anything, you are formatting it. You need to use DateTimeFormatter#print(ReadableInstant).

DateTime now = new org.joda.time.DateTime();
String pattern = "yyyy-MM-dd hh.mm.ss";
DateTimeFormatter formatter = DateTimeFormat.forPattern(pattern);
String formatted = formatter.print(now);
System.out.println(formatted);

which prints

2013-12-16 11.13.24

This doesn't match your format, but I'm basing it on your code, not on your expected output.

Java convert DateTime from yyyy-MM-dd HH:mm:ss.SSSSSSS to yyyy-MM-dd HH:mm:ss.S or from yyyy-MM-dd HH:mm:ss.SSSSSSS to yyyy-MM-dd HH:mm:ss.SSS

So, I started out with something like...

String text = "2021-03-10 16:37:02.4230000";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSSSSSS");

LocalDateTime ldt1 = LocalDateTime.parse("2021-03-10 16:37:02.4230000", formatter);
DateTimeFormatter shortFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.S");
System.out.println(shortFormatter.format(ldt1));

LocalDateTime ldt2 = LocalDateTime.parse("2021-03-10 16:39:51.0000000", formatter);
System.out.println(shortFormatter.format(ldt2));

Which prints out ...

2021-03-10 16:37:02.4
2021-03-10 16:39:51.0

Hmmm , not quite what we're looking for.

Lucky for us, there's the DateTimeFormatterBuilder class. So next, I tried something like...

DateTimeFormatter toFormatter = new DateTimeFormatterBuilder()
        .appendPattern("yyyy-MM-dd HH:mm:ss")
        .appendFraction(ChronoField.MILLI_OF_SECOND, 1, 9, true)
        .toFormatter();

System.out.println(toFormatter.format(ldt1));
System.out.println(toFormatter.format(ldt2));

Which prints out ...

2021-03-10 16:37:02.423
2021-03-10 16:39:51.0

Success /p>

Now, please note, I've not really used DateTimeFormatterBuilder before, so there might be some other, really super awesome cool way to achieve the same or better result, but hay, it's a nice start

Convert date object in dd/mm/yyyy hh:mm:ss format

You can fully format the string as mentioned in other posts. But I think your better off using the locale functions in the date object?

var d = new Date("2017-03-16T17:46:53.677"); console.log( d.toLocaleString() ); 

var d = new Date,
    dformat = [d.getMonth()+1,
               d.getDate(),
               d.getFullYear()].join('/')+' '+
              [d.getHours(),
               d.getMinutes(),
               d.getSeconds()].join(':');

Number.prototype.padLeft = function(base,chr){
    var  len = (String(base || 10).length - String(this).length)+1;
    return len > 0? new Array(len).join(chr || '0')+this : this;
}
// usage
//=> 3..padLeft() => '03'
//=> 3..padLeft(100,'-') => '--3' 

var d = new Date,
    dformat = [(d.getMonth()+1).padLeft(),
               d.getDate().padLeft(),
               d.getFullYear()].join('/') +' ' +
              [d.getHours().padLeft(),
               d.getMinutes().padLeft(),
               d.getSeconds().padLeft()].join(':');
//=> dformat => '05/17/2012 10:52:21'

const dt = new Date();
const padL = (nr, len = 2, chr = `0`) => `${nr}`.padStart(2, chr);

console.log(`${
    padL(dt.getMonth()+1)}/${
    padL(dt.getDate())}/${
    dt.getFullYear()} ${
    padL(dt.getHours())}:${
    padL(dt.getMinutes())}:${
    padL(dt.getSeconds())}`
);

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
SimpleDateFormat output = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date d = sdf.parse(time);
String formattedTime = output.format(d);