Java String to Date object of the format "yyyy-mm-dd HH:mm:ss"

Question

I need to convert a String containing date into an date object. The String will be of the format "yyyy-mm-dd HH:mm:ss.SSSSSS" and I want the same format in an date object.

For instance I have a string "2012-07-10 14:58:00.000000", and I need the resultant date object to be of the same format.

I have tried the below methods but, the resultant is not as expected.

java.util.Date temp = new SimpleDateFormat("yyyy-mm-dd HH:mm:ss.SSSSSS").parse("2012-07-10 14:58:00.000000");

DateFormat dateFormat = new SimpleDateFormat("yyyy-mm-dd HH:mm:ss");
                Date thisDate = dateFormat.parse("2012-07-10 14:58:00.000000");

The result is "Tue Jan 10 14:58:00 EST 2012". Please let me know where I am going wrong.

Thanks, Yeshwanth Kota

Answer 1

java.util.Date temp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").parse("2012-07-10 14:58:00.000000");

The mm is minutes you want MM

CODE

public class Test {

    public static void main(String[] args) throws ParseException {
        java.util.Date temp = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS")
                .parse("2012-07-10 14:58:00.000000");
        System.out.println(temp);
    }
}

Prints:

Tue Jul 10 14:58:00 EDT 2012

Answer 2

For future reference:

 yyyy => 4 digit year
 MM   => 2 digit month (you must type MM in ALL CAPS)
 dd   => 2 digit "day of the month"

 HH   => 2-digit "hour in day" (0 to 23)
 mm   => 2-digit minute (you must type mm in lowercase)
 ss   => 2-digit seconds
 SSS  => milliseconds

So "yyyy-MM-dd HH:mm:ss" returns "2018-01-05 09:49:32"

But "MMM dd, yyyy hh:mm a" returns "Jan 05, 2018 09:49 am"

The so-called examples at https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html show only output. They do not tell you what formats to use!

Answer 3

tl;dr

LocalDateTime.parse( 
    "2012-07-10 14:58:00.000000".replace( " " , "T" )  
)

Microseconds do not fit

You are attempting to squeeze a value with microseconds (six decimal digits) into a data type capable only of milliseconds resolution (three decimal digits). That is impossible.

Instead, use a data type with fine enough resolution. The java.time classes use nanosecond resolution (nine decimal digits).

Unzoned input does not fit a zoned type

You are attempting to put a value lacking any offset-from-UTC or time zone into a data type (Date) that only represents values in UTC. So you are adding information (UTC offset) not intended by the input.

Use an appropriate data type instead. Specifically, java.time.LocalDateTime.

Case-sensitive

Other Answers and Comments correctly explain that the formatting pattern codes are case-sensitive. So MM and mm have different effects.

Avoid legacy classes

The troublesome old date-time classes bundled with the earliest versions of Java are now legacy, supplanted by the java.time classes built into Java 8 and later.

ISO 8601

Your input strings nearly comply with the ISO 8601 standard formats. Replace the SPACE in the middle with a T to comply fully.

The java.time classes use the standard formats by default when parsing/generating strings. So no need to specify a formatting pattern.

Date-time objects have no "format"

and I need the resultant date object to be of the same format.

No, date-time objects do not have a "format". Do not conflate date-time objects with mere strings. Strings are inputs and outputs of the objects. The objects maintain their own internal representions of the date-time info, the details of which are irrelevant to us as calling programmers.

java.time

Your input lacks any indicator of offset-from-UTC or troublesome me zone. So we parse as a LocalDateTime objects which lacks those concepts.

String input = "2012-07-10 14:58:00.000000".replace( " " , "T" ) ;
LocalDateTime ldt = LocalDateTime.parse( input ) ;

Generating strings

To generate a String representing the value of your LocalDateTime:

• Call toString to get a String in standard ISO 8601 format.
• Use DateTimeFormatter for producing strings in either custom formats or automatically-localized formats.

Search Stack Overflow for more info as these topics have been covered many many times already.

ZonedDateTime

A LocalDateTime does not represent an exact point on the timeline.

To determine an actual moment, assign a time zone. For example noon in Kolkata India comes much earlier than noon in Paris France. Noon without a time zone could be happening at any point over a range of about 26-27 hours.

ZoneId z = ZoneId.of( "Asia/Kolkata" ) ;
ZonedDateTime zdt = ldt.atZone( z ) ;

---

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. Hibernate 5 & JPA 2.2 support java.time.

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 brought 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 (26+) bundle implementations of the java.time classes.
  • For earlier Android (<26), the process of API desugaring brings a subset of the java.time functionality not originally built into Android.
    • If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. See How to use ThreeTenABP….

Answer 4

Your not applying Date formator. rather you are just parsing the date. to get output in this format

yyyy-MM-dd HH:mm:ss.SSSSSS

we have to use format() method here is full example:- Here is full example:- it will take Date in this format yyyy-MM-dd HH:mm:ss.SSSSSS and as result we will get output as same as this format yyyy-MM-dd HH:mm:ss.SSSSSS

 import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

//TODO OutPut should LIKE in this format yyyy-MM-dd HH:mm:ss.SSSSSS.
public class TestDateExample {

public static void main(String args[]) throws ParseException {

    SimpleDateFormat changeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");

    java.util.Date temp = changeFormat.parse("2012-07-10 14:58:00.000000");
     Date thisDate = changeFormat.parse("2012-07-10 14:58:00.000000");  
    System.out.println(thisDate);
    System.out.println("----------------------------"); 
    System.out.println("After applying formating :");
    String strDateOutput = changeFormat.format(temp);
    System.out.println(strDateOutput);

}

}

Answer 5

its work for me SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); sdf.format(new Date));