Instant toEpochMilli() method in Java with Examples

The toEpochMilli() method of an Instant class is used to convert this instant to the number of milliseconds from the epoch of 1970-01-01T00:00:00Z to a long value. This method returns that long value.
Syntax:

public long toEpochMilli()

Returns: This method returns number of milliseconds since the epoch of 1970-01-01T00:00:00Z.
Exception: This method throws ArithmeticException if numeric overflow occurs.
Below programs illustrate the Instant.toEpochMilli() method:
Program 1:

Java

// Java program to demonstrate
// Instant.toEpochMilli() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a Instant object
        Instant instant
            = Instant.parse("2018-12-30T19:34:50.63Z");

        // get millisecond value using toEpochMilli()
        long value = instant.toEpochMilli();

        // print result
        System.out.println("Millisecond value: "
                           + value);
    }
}

Program 2:

Java

// Java program to demonstrate
// Instant.toEpochMilli() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a Instant object
        Instant instant = Instant.now();

        // current Instant
        System.out.println("Current Instant: "
                           + instant);

        // get millisecond value using toEpochMilli()
        long value = instant.toEpochMilli();

        // print result
        System.out.println("Millisecond value: "
                           + value);
    }
}

References: https://docs.oracle.com/javase/10/docs/api/java/time/Instant.html#toEpochMilli()