title: value for the annotation attribute must be constant expression
body: <p>I have a properties file that I read by spring annotation like this</p>
  
  <pre><code>    @Value("${platform}")
      private String platform;
  </code></pre>
  
  <p>after I get the platform parameter, I would like to read a second parameter depending on <code>platform</code> parameter value.</p>
  
  <pre><code>    @Value("${url." + platform + ."ws}")
      private String url;
  </code></pre>
  
  <p>but this gives error, "value for the annotation attribute must be constant expression". 
  since there are lots of parameter changes depending on "platform" value, I am looking for a generic solution.</p>