ChronoLocalDate format() method in Java with Examples

The format() method of ChronoLocalDate interface in Java method formats this date using the specified formatter.

Syntax:

public String format(DateTimeFormatter formatter)

Parameter: This method accepts a parameter obj which specifies the formatter to be used and it is not null.

Exceptions: The function throws only DateTimeException which occurs during an error in printing.

Return Value: It returns the formatted date string and not null.

Below programs illustrate the format() method of ChronoLocalDate in Java:

Program 1:

// Program to illustrate the format() method

import java.util.*;
import java.time.*;
import java.time.chrono.*;
import java.time.format.DateTimeFormatter;

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

        // Parses the date
        ChronoLocalDate dt
            = LocalDate.parse("2018-11-01");
        System.out.println(dt);

        // Function call
        DateTimeFormatter formatter
            = DateTimeFormatter
                  .ofPattern("dd/MM/YYYY");

        System.out.println(formatter.format(dt));
    }
}

Output:

2018-11-01
01/11/2018

Program 2: To illustrate the exception.

// Program to illustrate the format() method
// Exception Program

import java.util.*;
import java.time.*;
import java.time.chrono.*;
import java.time.format.DateTimeFormatter;

public class GfG {
    public static void main(String[] args)
    {
        try {
            // Parses the date
            ChronoLocalDate dt
                = LocalDate.parse("2018-01-32");
            System.out.println(dt);

            // Function call
            DateTimeFormatter formatter
                = DateTimeFormatter
                      .ofPattern("dd/MM/YYYY");

            System.out.println(formatter.format(dt));
        }
        catch (Exception e) {
            System.out.println(e);
        }
    }
}

Output:

java.time.format.DateTimeParseException: 
 Text '2018-01-32' could not be parsed:
 Invalid value for DayOfMonth (valid values 1 - 28/31): 32

Reference: https://docs.oracle.com/javase/9/docs/api/java/time/chrono/ChronoLocalDate.html#format-java.time.format.DateTimeFormatter-