LocalDateTime withNano() method in Java with Examples

withNano() method of LocalDateTime class in Java is used to get a copy of this LocalDateTime with the nano-seconds changed to the nano-seconds passed as the parameter to this method. The remaining values of this LocalDateTime remain the same.

Syntax:

public LocalDateTime withNano(int nanoSeconds)

Parameter: Single mandatory parameter nanoSeconds which specify the nano-seconds to be set in the resultant LocalDateTime instance. The value of these nano-seconds can range from 0 to 999999999.

Return Type: A LocalDateTime instance with the nano-seconds changed to the nano-seconds passed as the parameter to this method. The remaining values of this LocalDateTime remain the same.

Exceptions: The function throws a DateTimeException if the nano-seconds value is invalid.

Example 1:

Java

// Java Program to illustrate withNano() method of
// LocalDateTime class

// Importing required classes
import java.time.*;
import java.util.*;

// Main class
public class GFG {

    // Main driver method
    public static void main(String[] args)
    {

        // Creating tan instance of LocalDateTime class
        LocalDateTime dt = LocalDateTime.now();

        // Getting the String representation of this
        // LocalDateTime
        System.out.println("Original LocalDateTime: "
                           + dt.toString());

        // Getting a new LocalDateTime with nano-seconds 0
        System.out.println("New LocalDateTime: "
                           + dt.withNano(0));
    }
}

Output:

Original LocalDateTime: 2018-11-30T12:54:17.484
New LocalDateTime: 2018-11-30T12:54:17

Example 2:

Java

// Java Program to illustrate withNano() method of
// LocalDateTime class

// Importing required classes
import java.time.*;
import java.util.*;

// Main class
public class GFG {

    // Main driver method
    public static void main(String[] args)
    {
        // Creating an object of LocalDateTime class inside
        // main()
        LocalDateTime dt
            = LocalDateTime.parse("2015-04-06T10:15:30");

        // Getting the String representation of this
        // LocalDateTime
        System.out.println("Original LocalDateTime: "
                           + dt.toString());

        // Getting a new LocalDateTime with nano-seconds
        // 99999
        System.out.println("New LocalDateTime: "
                           + dt.withNano(99999));
    }
}

Output:

Original LocalDateTime: 2015-04-06T10:15:30
New LocalDateTime: 2015-04-06T10:15:30.000099999

Now we will be handling with care withNano(0) method is used for removing the nano seconds and retaining date-time till seconds.

Example 3:

Note: Special Case: If the seconds value is:00, then while doing at toString() will eliminate the seconds portion.

Example:

Java

// Java Program to illustrate withNano() method of
// LocalDateTime class

// Importing required classes
import java.io.*;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

// Main class
class GFG {

    // Main driver method
    public static void main(String[] args)
        throws InterruptedException
    {

        // Creating an object of DateTimeFormatter class
        DateTimeFormatter dtf
            = DateTimeFormatter.ISO_DATE_TIME;

        // If condition holds true
        while (true) {

            // Making thread to sleep for 500 nanoseconds
            Thread.sleep(500);

            // Print and display commands
            System.out.println("Original :00 seconds --> "
                               + LocalDateTime.now());
            System.out.println(
                "Without Formatter(Observe when seconds is :00) --> "
                + LocalDateTime.now().withNano(0));
            System.out.println(
                "With Formatter -> "
                + LocalDateTime.now().withNano(0).format(
                    dtf));
        }
    }
}

Output: