The new Date and Time API introduce in Java 8 because of the bad design and concurrency issue in the old Date API.
In this blog, I have posted the sample code for new date time API. Like getting the current date, time, zoneId, and get next SATURDAY. And formatting the date.
Date and Time Classes
- LocalDate : can get the system date
- LocalTime : can get the system time
- LocalDateTime : Combination of LocalDate and LocalTime
- ZonedDateTime : Can get the zone specific date and time
- DateTimeFormatter : Replacement of SimpleDateFormat
- TemporalAdjusters : utility class, provide some static method to find previous or next date of particular days.
Sample code for new Date and Time API
package com.samplecoder.datetime;
import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjusters;
public class DateTime {
public static void main(String... arg) {
LocalDate localDate = LocalDate.now();
System.out.println("Current date: "+localDate);
LocalTime localTime = LocalTime.now();
System.out.println("Current Time: "+localTime);
LocalDateTime localDateTime = LocalDateTime.of(localDate, localTime);
System.out.println("Current Date&Time: "+localDateTime);
ZoneId zoneId = ZoneId.systemDefault();
System.out.println("System default time zone: "+zoneId);
ZonedDateTime zonedDateTime = ZonedDateTime.of(localDateTime, zoneId);
System.out.println("Current Zoned Date&Time: "+zonedDateTime);
System.out.println("Format Date: "+localDate.format(DateTimeFormatter.ofPattern("MM/dd/yyyy")));
localDate = localDate.plus(2, ChronoUnit.DAYS);
System.out.println("Plus 2 Days from current date: "+localDate.format(DateTimeFormatter.ofPattern("MM/dd/yyyy")));
System.out.println("Day of week: "+localDateTime.getDayOfWeek());
System.out.println("Day of month: "+localDateTime.getDayOfMonth());
System.out.println("Day of year: "+localDateTime.getDayOfYear());
System.out.println("Year: "+localDateTime.getYear());
LocalDateTime nextSaturday = localDateTime.with( TemporalAdjusters.firstDayOfMonth()).with(TemporalAdjusters.previousOrSame(DayOfWeek.FRIDAY));
System.out.println("Next Saturday: "+nextSaturday);
}
}
Result
Current date: 2021-07-20
Current Time: 07:46:41.189
Current Date&Time: 2021-07-20T07:46:41.189
System default time zone: Asia/Calcutta
Current Zoned Date&Time: 2021-07-20T07:46:41.189+05:30[Asia/Calcutta]
Format Date: 07/20/2021
Plus 2 Days from current date: 07/22/2021
Day of week: TUESDAY
Day of month: 20
Day of year: 201
Year: 2021
Next Saturday: 2021-06-25T07:46:41.189
Conclusion
I believe you have some understanding about new Date Time API in Java 8. And you know the use of TemporalAdjusters and DateTimeFormatter.
