title: Creating QR Code as Base64 String using Spring Boot
body: <p>I am creating a microservice using spring boot where in i have a file handling.
  My task is to write the QR code to image file and base64 encode to transfer over network.
  Because I need to write to an image file and then read and then base64 encode it , I need to first create the image file and then write to it. 
  Creating a temperory folder and keep the file ?, create a folder in root  directory and keep the file? or use the <em>java.io.tmpdir</em> ....
  <strong>Note</strong>: I have no use of this file once I encode it. Also there are lot of user to whom we will be exposing this service as rest api.
  I want to know what is the best way to do this.</p>