isAfter() method of an Instant class is used to check if this instant is after the instant passed as parameter or not. This method returns a boolean value showing the same.
Syntax:
public boolean isAfter(Instant otherInstant)
Parameter: This method takes a parameter otherInstant which is the other instant to compare to this instant. It should not be null.
Returns: This method returns true if this instant is after the specified instant. Else it returns false.
Exception: This method throws NullPointerException if otherInstant passed as the parameter is null.
Below programs illustrate the isAfter() method:
Program 1:
// Java program to demonstrate// Instant.isAfter() method  import java.time.*;  public class GFG {    public static void main(String[] args)    {          // create a Instant object        Instant instant1            = Instant.parse("2018-12-30T19:34:50.63Z");          // create other Instant        Instant instant2            = Instant.parse("2018-12-29T09:24:00.63Z");          // print instances        System.out.println("Instance 1: " + instant1);        System.out.println("Instance 2: " + instant2);          // check if instant1 is after instant2        // using isAfter()        boolean value = instant1.isAfter(instant2);          // print result        System.out.println("Is Instant1 after Instant2: "                           + value);    }} |
Output:
Instance 1: 2018-12-30T19:34:50.630Z Instance 2: 2018-12-29T09:24:00.630Z Is Instant1 after Instant2: true
Program 2:
// Java program to demonstrate// Instant.isAfter() method  import java.time.*;  public class GFG {    public static void main(String[] args)    {          // create a Instant object        Instant instant1            = Instant.parse("2018-10-30T19:34:50.63Z");          // create other Instant        Instant instant2 = Instant.now();          // print instances        System.out.println("Instance 1: " + instant1);        System.out.println("Instance 2: " + instant2);          // check if instant1 is after instant2        // using isAfter()        boolean value = instant1.isAfter(instant2);          // print result        System.out.println("Is Instant1 after Instant2: "                           + value);    }} |
Output:
Instance 1: 2018-10-30T19:34:50.630Z Instance 2: 2018-11-27T04:52:08.970Z Is Instant1 after Instant2: false
Program 3: To show Exception thrown by isAfter()
// Java program to demonstrate// Instant.isAfter() method  import java.time.*;  public class GFG {    public static void main(String[] args)    {          // create a Instant object        Instant instant1            = Instant.parse("2018-10-30T19:34:50.63Z");          // create other Instant        Instant instant2 = null;          try {              // print instances            System.out.println("Instance 1: " + instant1);            System.out.println("Instance 2: " + instant2);              // check if instant1 is after instant2            // using isAfter()            boolean value = instant1.isAfter(instant2);        }        catch (Exception e) {            // print result            System.out.println("Exception: " + e);        }    }} |
Output:
Instance 1: 2018-10-30T19:34:50.630Z Instance 2: null Exception: java.lang.NullPointerException
References: https://docs.oracle.com/javase/10/docs/api/java/time/Instant.html#isAfter(java.time.Instant)
