Write String as bytes to file with DataOutputStream

In this example we shall show you how to write a String as bytes to file with the DataOutputStream. The DataOutputStream lets an application write primitive Java data types to an output stream in a portable way. An application can then use a data input stream to read the data back in. To write a String as bytes to file with the DataOutputStream one should perform the following steps:

  • Create a FileOutputStream to write to the file with the specified name.
  • Create a DataOutputStream with the FileOutputStream.
  • Use writeBytes(String s) API method. It writes out the string to the underlying output stream as a sequence of bytes,

as described in the code snippet below.

package com.javacodegeeks.snippets.core;


public class WriteStringAsBytesToFileWithDataOutputStream {
	public static void main(String[] args) {
		String filename = "output.txt";
		String output = "Java Code Geeks - Java Examples";
		FileOutputStream fos = null;
		DataOutputStream dos = null;

		try {
			fos = new FileOutputStream(filename);
			dos = new DataOutputStream(fos);
		catch (FileNotFoundException fnfe) {
			System.out.println("File not found" + fnfe);
		catch (IOException ioe) {
			System.out.println("Error while writing to file" + ioe);
		finally {
			try {
				if (dos != null) {
				if (fos != null) {
			catch (Exception e) {
				System.out.println("Error while closing streams" + e);

This was an example of how to write a String as bytes to file with the DataOutputStream in Java.

Ilias Tsagklis

Ilias is a software developer turned online entrepreneur. He is co-founder and Executive Editor at Java Code Geeks.
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
Back to top button