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Java LocalDateTime Class | getLong() Method with Example

LocalDateTime Class getLong() method: Here, we are going to learn about the getLong() method of LocalDateTime Class with its syntax and example.
Submitted by Preeti Jain, on June 06, 2020

LocalDateTime Class getLong() method

• getLong() method is available in java.time package.
• getLong() method is used to get the value as long for the given temporal field from this date-time object.
• getLong() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• getLong() method may throw an exception at the time of returning value as long.
  • DateTimeException – This exception may throw when the given field couldn’t be generated.
  • UnsupportedTemporalTypeException – This exception may throw when the given field is unsupported.
  • ArithmeticException – This exception may throw when the calculated result exceeds the limit.

Syntax:

    public long getLong(TemporalField t_field);

Parameter(s):

• TemporalField t_field – represents the field of the returned value.

Return value:

The return type of this method is long, it returns the value for the given field as long from this date-time.

Example:

// Java program to demonstrate the example 
// of getLong(TemporalField t_field) method 
// of LocalDateTime

import java.time.*;
import java.time.temporal.*;

public class GetLongOfLocalDateTime {
    public static void main(String args[]) {
        // Instantiates two LocalDateTime
        LocalDateTime da_ti1 = LocalDateTime.parse("2005-10-05T10:10:10");
        LocalDateTime da_ti2 = LocalDateTime.now();

        // Display da_ti1, da_ti2
        System.out.println("LocalDateTime da_ti1 and da_ti2: ");
        System.out.println("da_ti1: " + da_ti1);
        System.out.println("da_ti2: " + da_ti2);

        System.out.println();

        // Here, this method returns the given 
        // field value from this date-time (da_ti1)
        // i.e. here MONTH_OF_YEAR field value will
        // be returned from this date-time object
        // da_ti1
        long get_val = da_ti1.getLong(ChronoField.MONTH_OF_YEAR);

        // Display get_val
        System.out.print("da_ti1.getLong(ChronoField.MONTH_OF_YEAR): ");
        System.out.println(get_val);

        // Here, this method returns the given field
        // value from this date-time (da_ti2) i.e. here
        // MICRO_OF_SECOND field value will be returned
        // from this date-time object da_ti2
        get_val = da_ti2.getLong(ChronoField.MICRO_OF_SECOND);

        // Display get_val
        System.out.print("da_ti2.getLong(ChronoField.MICRO_OF_SECOND): ");
        System.out.println(get_val);
    }
}

Output

LocalDateTime da_ti1 and da_ti2: 
da_ti1: 2005-10-05T10:10:10
da_ti2: 2020-06-05T03:01:53.798565

da_ti1.getLong(ChronoField.MONTH_OF_YEAR): 10
da_ti2.getLong(ChronoField.MICRO_OF_SECOND): 798565