CODEWITHSUNDEEP
javaandroid
user3776241
user3776241

Reputation: 543

Date to timestamp

I'm trying to convert this date string 2014-07-17T22:41:17+0000 to a timestmap, similar to this: 1405645259000.

I've tried something similar to this: 

String string = "January 2, 2010";
Date date = new SimpleDateFormat("MMMM d, yyyy", Locale.ENGLISH).parse(string);
System.out.println(date);

How do I convert this (2014-07-17T22:41:17+000) to a Date? What is the correct format? I'm at a loss.

Upvotes: 0

Views: 116

Answers (3)

Basil Bourque
Basil Bourque

Reputation: 338516

tl;dr

OffsetDateTime.parse( "2014-07-17T22:41:17+0000" )
              .toInstant()
              .toEpochMilli()

Avoid java.util.Date

Your question is easy in Joda-Time or the new java.time package in Java 8. Avoid java.util.Date and .Calendar as they are notoriously troublesome.

ISO 8601

Your String is in standard format, complying with ISO 8601. Both libraries mentioned above use ISO 8601 as their defaults for parsing and generating strings.

java.time

The OffsetDateTime class represents a moment on the timeline with an offset-from-UTC and with a resolution in nanoseconds.

OffsetDateTime odt = OffsetDateTime.parse( "2014-07-17T22:41:17+0000" );

From there you can ask for the count-of-milliseconds-since-epoch via the Instant class. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction). 

long millisecondsSinceEpoch = odt.toInstant().toEpochMilli();

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, & java.text.SimpleDateFormat.

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

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 and 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 SE 7
    • Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
  • Android

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.

Joda-Time

Example code on Joda-Time 2.3.

long millisSinceEpoch = new DateTime( "2014-07-17T22:41:17+0000" ).getMillis();

Upvotes: 1

vivek_ganesan
vivek_ganesan

Reputation: 698

Take a look at http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Your date string has the same format as 

yyyy-MM-dd'T'HH:mm:ssZ  //Eg: 2001-07-04T12:08:56-0700

So, your code should be:

String string = "2014-07-17T22:41:17+0000";
Date date = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.ENGLISH).parse(string);
System.out.println(date);

Upvotes: 6

Jens
Jens

Reputation: 69440

use this pattern:

Date date = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", Locale.ENGLISH).parse(string);

Upvotes: 3

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