Java code for getting current time [duplicate]

Question

Try this:

import java.text.SimpleDateFormat;
import java.util.Calendar;

public class currentTime {

    public static void main(String[] args) {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
        System.out.println( sdf.format(cal.getTime()) );
    }

}

You can format SimpleDateFormat in the way you like. For any additional information you can look in java api:

SimpleDateFormat

Calendar

Both

new java.util.Date()

and

System.currentTimeMillis()

will give you current system time.

tl;dr

Instant.now()  // UTC

…or…

ZonedDateTime.now(
    // Specify time zone.
    ZoneId.of( "Pacific/Auckland" )
)  

Details

The bundled java.util.Date/.Calendar classes are notoriously troublesome. Avoid them. They are now legacy, supplanted by the java.time framework.

Instead, use either:

• java.time
  Built-in with Java 8 and later. Official successor to Joda-Time.
  Back-ported to Java 6 & 7 and to Android.
• Joda-Time
  Third-party library, open-source, free-of-cost.

java.time

ZonedDateTime zdt = ZonedDateTime.now();

If needed for old code, convert to java.util.Date. Go through at Instant which is a moment on the timeline in UTC.

java.util.Date date = java.util.Date.from( zdt.toInstant() );

Time Zone

Better to specify explicitly your desired/expected time zone rather than rely implicitly on the JVM’s current default time zone.

ZoneId zoneId = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.now( zoneId );  // Pass desired/expected time zone.

Joda-Time

FYI, the Joda-Time project is now in maintenance mode, with the team advising migration to the java.time classes.

DateTime now = DateTime.now();

To convert from a Joda-Time DateTime object to a java.util.Date for inter-operating with other classes…

java.util.Date date = now.toDate();

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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.

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

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

Where to obtain the java.time classes?

• Java SE 8, Java SE 9, and later
  • Built-in.
  • 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
  • Much 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, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

System.currentTimeMillis()

everything else works off that.. eg new Date() calls System.currentTimeMillis().

Try this way, more efficient and compatible:

SimpleDateFormat time_formatter = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss.SSS");
String current_time_str = time_formatter.format(System.currentTimeMillis());
//Log.i("test", "current_time_str:" + current_time_str);

Just to inform for furthers developers, and thankfully to Basil Bourque, I just wanna add my stone to this topic.

If you want simply get the HH:MM:SS format then do this:

LocalTime hour = ZonedDateTime.now().toLocalTime().truncatedTo(ChronoUnit.SECONDS);

Cheers.

P.S.: This will work only at least with Java 8 !