Converting byte[] Array to String in Java

This tutorial will teach you how to convert an array of bytes to a string of characters in Java.

Additionally, you might be interested in learning how to convert an image/file byte[] array to a Base64 encoded String.  If you are, then check the following tutorial.

• How to Convert Image byte[] Array to Base64 encoded String in Java

Converting String to byte[]

Let’s assume we have a simple line of text converted to an array of bytes.

byte[] helloWorldBytes = "Hello world".getBytes(StandardCharsets.UTF_8);

Now that we have an array of bytes, we would like to convert it back to a String.

Converting byte[] to String

String helloWorldString = new String(helloWorldBytes, StandardCharsets.UTF_8);

Below is a complete code example that demonstrates:

1. How to convert a plain text to an array of bytes in Java. And then,
2. How to convert a byte[] array back to a String value.

import java.nio.charset.StandardCharsets;

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

        byte[] helloWorldBytes = "Hello world".getBytes(StandardCharsets.UTF_8);

        String helloWorldString = new String(helloWorldBytes, StandardCharsets.UTF_8);

        System.out.println(helloWorldString);
    }
}

Converting byte[] to a Base64 Encoded String

Sometimes we need to convert the byte[] array to a Base64 encoded String. This is helpful when you need to send an array of bytes over the network.

To convert an array of bytes to a Base64 encoded String, you will use the Base64 java class from the java.util package.

String base64EncodedString = Base64.getEncoder().encodeToString(helloWorldBytes);

Below is a complete code example demonstrating how to encode an array of bytes to a Base64 encoded String in Java.

import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class App {
    public static void main(String[] args) {
        byte[] helloWorldBytes = "Hello world".getBytes(StandardCharsets.UTF_8);

        String base64EncodedString = Base64.getEncoder().encodeToString(helloWorldBytes);
        System.out.println(base64EncodedString);

    }
}

Decoding Base64 String to byte[]

A Base64 encoded string can be easily decoded back to a byte[] array.

byte[] bytesFromBase64String = Base64.getDecoder().decode(base64EncodedString);

I hope this very short blog post was helpful to you.

There are many other useful tutorials you can find on this site. To find Java-related tutorials, check out the Java tutorials page.

Happy learning!