[java] Decoding a Base64 string in Java

I'm trying to decode a simple Base64 string, but am unable to do so. I'm currently using the org.apache.commons.codec.binary.Base64 package.

The test string I'm using is: abcdefg, encoded using PHP YWJjZGVmZw==.

This is the code I'm currently using:

Base64 decoder = new Base64();
byte[] decodedBytes = decoder.decode("YWJjZGVmZw==");
System.out.println(new String(decodedBytes) + "\n") ;   

The above code does not throw an error, but instead doesn't output the decoded string as expected.

This question is related to java base64

The answer is


If you don't want to use apache, you can use Java8:

byte[] decodedBytes = Base64.getDecoder().decode("YWJjZGVmZw=="); 
System.out.println(new String(decodedBytes) + "\n");

Commonly base64 it is used for images. if you like to decode an image (jpg in this example with org.apache.commons.codec.binary.Base64 package):

byte[] decoded = Base64.decodeBase64(imageJpgInBase64);
FileOutputStream fos = null;
fos = new FileOutputStream("C:\\output\\image.jpg");
fos.write(decoded);
fos.close();

Modify the package you're using:

import org.apache.commons.codec.binary.Base64;

And then use it like this:

byte[] decoded = Base64.decodeBase64("YWJjZGVmZw==");
System.out.println(new String(decoded, "UTF-8") + "\n");

The following should work with the latest version of Apache common codec

byte[] decodedBytes = Base64.getDecoder().decode("YWJjZGVmZw==");
System.out.println(new String(decodedBytes));

and for encoding

byte[] encodedBytes = Base64.getEncoder().encode(decodedBytes);
System.out.println(new String(encodedBytes));