title: How to change string to lower case inside Java Spring @PropertySource annotation
body: <p>I have a statement</p>
  
  <pre><code>`@PropertySource("${env}.properties")` 
  </code></pre>
  
  <p>where 'env' is my command line parameter. </p>
  
  <p>If env=QA, this would result in my config file being named QA.properties. </p>
  
  <p><strong>I want to ensure that the name of the config file is always in lower case (i.e. 'qa.properties)'.</strong></p>