Tutorial

String to byte array, byte array to String in Java

Published on August 3, 2022
Default avatar

By Pankaj

String to byte array, byte array to String in Java

While we believe that this content benefits our community, we have not yet thoroughly reviewed it. If you have any suggestions for improvements, please let us know by clicking the “report an issue“ button at the bottom of the tutorial.

Today we will learn how to convert String to byte array in java. We will also learn how to convert byte array to String in Java.

String to byte array

We can use String class getBytes() method to encode the string into a sequence of bytes using the platform’s default charset. This method is overloaded and we can also pass Charset as argument. Here is a simple program showing how to convert String to byte array in java.

package com.journaldev.util;

import java.util.Arrays;

public class StringToByteArray {

	public static void main(String[] args) {
		String str = "PANKAJ";
		byte[] byteArr = str.getBytes();
		// print the byte[] elements
		System.out.println("String to byte array: " + Arrays.toString(byteArr));
	}
}

Below image shows the output when we run the above program. java string to byte array, string to byte array in java We can also get the byte array using the below code.

byte[] byteArr = str.getBytes("UTF-8");

However if we provide Charset name, then we will have to either catch UnsupportedEncodingException exception or throw it. Better approach is to use StandardCharsets class introduced in Java 1.7 as shown below.

byte[] byteArr = str.getBytes(StandardCharsets.UTF_8);

That’s all the different ways to convert String to byte array in java.

Java byte array to String

Let’s look at a simple program showing how to convert byte array to String in Java.

package com.journaldev.util;

public class ByteArrayToString {

	public static void main(String[] args) {
		byte[] byteArray = { 'P', 'A', 'N', 'K', 'A', 'J' };
		byte[] byteArray1 = { 80, 65, 78, 75, 65, 74 };

		String str = new String(byteArray);
		String str1 = new String(byteArray1);

		System.out.println(str);
		System.out.println(str1);
	}
}

Below image shows the output produced by the above program. byte array to string in java, convert byte array to string Did you notice that I am providing char while creating the byte array? It works because of autoboxing and char ‘P’ is being converted to 80 in the byte array. That’s why the output is the same for both the byte array to string conversion. String also has a constructor where we can provide byte array and Charset as an argument. So below code can also be used to convert byte array to String in Java.

String str = new String(byteArray, StandardCharsets.UTF_8);

String class also has a method to convert a subset of the byte array to String.

byte[] byteArray1 = { 80, 65, 78, 75, 65, 74 };
String str = new String(byteArray1, 0, 3, StandardCharsets.UTF_8);

Above code is perfectly fine and ‘str’ value will be ‘PAN’. That’s all about converting byte array to String in Java.

You can checkout more array examples from our GitHub Repository.

Reference: getBytes API Doc

Thanks for learning with the DigitalOcean Community. Check out our offerings for compute, storage, networking, and managed databases.

Learn more about us


About the authors
Default avatar
Pankaj

author

Still looking for an answer?

Ask a questionSearch for more help

Was this helpful?
 
JournalDev
DigitalOcean Employee
DigitalOcean Employee badge
April 12, 2020

Thx a lot

- dfds

    JournalDev
    DigitalOcean Employee
    DigitalOcean Employee badge
    April 25, 2019

    how to read a binary file and write in a text file or xml file using java

    - vasanthan

      JournalDev
      DigitalOcean Employee
      DigitalOcean Employee badge
      April 12, 2019

      good night , can you tell me if the code from string array list to byte array list

      - monika

        JournalDev
        DigitalOcean Employee
        DigitalOcean Employee badge
        July 13, 2018

        What is the use (some real-time application usage) of converting a string into a byte array?

        - B Ekam

          Try DigitalOcean for free

          Click below to sign up and get $200 of credit to try our products over 60 days!

          Sign up

          Join the Tech Talk
          Success! Thank you! Please check your email for further details.

          Please complete your information!

          Get our biweekly newsletter

          Sign up for Infrastructure as a Newsletter.

          Hollie's Hub for Good

          Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.

          Become a contributor

          Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.

          Welcome to the developer cloud

          DigitalOcean makes it simple to launch in the cloud and scale up as you grow — whether you're running one virtual machine or ten thousand.

          Learn more
          DigitalOcean Cloud Control Panel