Formatter flush() method in Java with Examples

The flush() method is a built-in method of the java.util.Formatter which flushes the formatter. Writing any buffered output in its destination to the underlying operating system is referred to as Flushing.

Syntax:

public void flush()

Parameters: The function accepts no parameter.

Return Value: The function returns nothing, it just flushes the formatter. Hence the return type is void.

Errors and Exceptions: The function throws a FormatterClosedException when this function is used after closing the formatter.

Below is the implementation of the above function:

Program 1:

// Java program to implement
// the above function

import java.util.Formatter;
import java.util.Locale;

public class Main {

    public static void main(String[] args)
    {

        // Get the string Buffer
        StringBuffer buffer = new StringBuffer();

        // Object creation
        Formatter frmt
            = new Formatter(buffer,
                            Locale.CANADA);

        // Format a new string
        String name = "My name is Gopal Dave";
        frmt.format("What is your name? \n%s !",
                    name);

        // Print the Formatted string
        System.out.println(frmt);

        // flushes the formatter
        frmt.flush();
        System.out.println("Flushed");
    }
}

Output:

What is your name? 
My name is Gopal Dave !
Flushed

Program 2:

// Java program to implement
// the above function

import java.util.Formatter;
import java.util.Locale;

public class Main {

    public static void main(String[] args)
    {
        try {
            // Get the string Buffer
            StringBuffer buffer
                = new StringBuffer();

            // Object creation
            Formatter frmt
                = new Formatter(buffer,
                                Locale.CANADA);

            // Format a new string
            String name = "My name is Gopal Dave";
            frmt.format("What is your name? \n%s !",
                        name);

            // Print the Formatted string
            System.out.println(frmt);

            // closes the formatter
            frmt.close();

            // close the frmt
            frmt.flush();
            System.out.println("Flushed");
        }
        catch (Exception e) {
            System.out.println("\nException is: "
                               + e);
        }
    }
}

Output:

What is your name? 
My name is Gopal Dave !

Exception is: java.util.FormatterClosedException

Reference: https://docs.oracle.com/javase/10/docs/api/java/util/Formatter.html#close()