How to get current date time in the format 2019101620000583?

I am new to Java. I am trying to store current date time in long format, like 2019110820000583.

I tried using System.currentTimeMillis() but it doesn't give date and time combined. It gives me result like 1573205716048.

Solution

java.time

Get the current moment in UTC.

OffsetDateTime odt = OffsetDateTime.now( ZoneOffset.UTC ) ;

Define a formatting pattern for your desired output.

DateTimeFormatter f = DateTimeFormatter.ofPattern( "uuuuMMddHHmmss" ) ;

Generate a String with text in your desired format.

String output = odt.format( f ) ;

For a time zone, similar to code above but use ZonedDateTime in place of OffsetDateTime.

ZonedDateTime.now( ZoneId.of( "America/Montreal" ) )

ISO 8601

Tip: Generally best to use the standard ISO 8601 formats when serializing date-time values as text. To comply with the “basic” version of ISO 8601:

insert a T between the date portion and the time-of-day portion.
Append a Z for a moment in UTC. Otherwise append the offset.

So this:

DateTimeFormatter.ofPattern( "uuuuMMdd'T'HHmmssXXXXX" )

See this full example run live at IdeOne.com.

OffsetDateTime odt = OffsetDateTime.now( ZoneOffset.UTC ) ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "uuuuMMdd'T'HHmmssXXXXX" ) ;
String output = odt.format( f ) ;

odt.toString(): 2019-11-09T04:38:47.972145Z

output: 20191109T043847Z

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.

Where to obtain the java.time classes?

Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
- Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
- Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
- Later versions of Android bundle implementations of the java.time classes.
- For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….