Date and Time in Java
April 30, 2017
Categorised in: Java Core
Understanding through code
import java.text.DateFormat;
import java.time.LocalDateTime;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.GregorianCalendar;
public class DateTime {
public static void main( String[] args ){
Date date = new Date();
System.out.println(date);
GregorianCalendar gc = new GregorianCalendar(2010, 5, 15);
gc.add(GregorianCalendar.DATE, 1);
Date date1 = gc.getTime();
System.out.println(date1);
DateFormat df = DateFormat.getDateInstance(DateFormat.FULL);
System.out.println(df.format(date1));
LocalDateTime ldt = LocalDateTime.now();
System.out.println(ldt);
LocalDate ld = LocalDate.of(2010, 5, 15);
System.out.println(ld);
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("M/d/yyyy");
System.out.println(dtf.format(ld));
}
}
Output
- Mon May 01 00:47:49 IST 2017
- Wed Jun 16 00:00:00 IST 2010
- Wednesday, 16 June, 2010
- 2017-05-01T00:47:50.722
- 2010-05-15
- 5/15/2010
Notes
- Date API is the first API for date and is minimalist API.
- GregorianCalendar is used for showing specific date.
- Notice that we get June instead of ‘May’ since we passed 5. It’s index which starts from 0 representing January.
- gc.add() adds a day.
- DateFormat is for formatting the date in a readable manner.
- Java Version 8:
- LocalDateTime (equivalent to old Date. Imports through java.time instead of java.util)
- LocalDateTime gives time in format that is mostly used in databases
- LocalDate starts numbering of months from 1. So we get 2010-05-15
- DateTimeFormatter is equivalent to DateFormat in old API
Pratik Kataria is currently learning Springboot and Hibernate.
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