How to encode an attachment to Base64 in Jmeter?

Jmeter has many potions to convert a variable to "Base64", below are a few options

1. Bean shell pre processor
2. BeanShell PostProcessor
3. BeanShell Sampler.

Below is the "bean shell" code, which used in "Bean shell pre processor" to convert variable to Base64

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

String emailIs= vars.get("session");

byte[] encryptedUid = Base64.encodeBase64(emailIs.getBytes());
vars.put("genStringValue",new String(encryptedUid));

Example :

Before Base64 :jdwqoeendwqqm12sdw

After Base64 :amR3cW9lZW5kd3FxbTEyc2R3

Converted using Jmeter :

Converted Using base64 site: