Java BufferedOutputStream flush() method example

public void flush()
throws IOException

This method returns void.

Requires Java 1.0 and up

Below is a java code demonstrates the use of flush() method of BufferedOutputStream class. The example presented might be simple however it shows the behaviour of the flush().

package com.javatutorialhq.java.examples;

import java.io.BufferedOutputStream;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Scanner;



/*
 * This example source code demonstrates the use of  
 * flush() method of BufferedOutputStream class
 */

public class BufferedOutputStreamFlushExample {

	public static void main(String[] args) {	
		
		
		try {
			// initialize File object
			File f = new File("C:javatutorialhqoutputtest_out.txt");
			
			// instantiate a new FileOutputStream
			FileOutputStream fos = new FileOutputStream(f);
			
			// using the above FileOutputStream
			// instantiate a BufferedOutputStream object
			BufferedOutputStream buffOut = new BufferedOutputStream(fos);
			
			BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(buffOut));
			bw.write("This is a test string");
			// flush and close the BufferedWriter
			bw.flush();
			bw.close();
			
			// flush and close the BufferedOutputStream
			buffOut.flush();
			buffOut.close();
			
			// flush and close the FileOutputStream
			fos.flush();
			fos.close();
			
			// read the contents of the file
			Scanner s = new Scanner(f);
			while(s.hasNextLine()){
				System.out.println(s.nextLine());
			}
			s.close();
		} catch (FileNotFoundException e) {
			System.out.println("File path not found");
		} catch (IOException e) {
			System.out.println("IOException occured");
		}
		

	}

}

Below is the sample output when you run the above example.

• Java BufferedOutputStream Class Tutorial
• Java Tutorial

• Oracle Java Documentation