title: Spring Boot: @Value returns always null
body: <p>I would like to use a value from <code>application.properties</code> file in order to pass it in the method in another class. The problem is that the value returns always <code>NULL</code>. What could be the problem? Thanks in advance.</p>
  
  <p><strong><code>application.properties</code></strong></p>
  
  <pre><code>filesystem.directory=temp
  </code></pre>
  
  <p><strong><code>FileSystem.java</code></strong></p>
  
  <pre><code>@Value("${filesystem.directory}")
  private static String directory;
  </code></pre>