title: Don't fail if @Value is not supplied in properties?
body: <p>I import a dependency that have some services with <code>@Value</code> fields. In my spring boot application I don't use these services but I still use some other classes from this dependency, now if I run my application it will fail that it can't resolve the placeholders, e.g.</p>
  
  <blockquote>
    <p>Caused by: java.lang.IllegalArgumentException: Could not resolve
    placeholder 'apn.authentication.token.teamId' in value
    "${apn.authentication.token.teamId}"</p>
  </blockquote>
  
  <p>So to fix this I have to define the value in my properties. I searched for a setting to let my app not fail on unknown values but I couldn't find a way to do it.</p>
  
  <p>Is there a way to let my spring boot app launch even if there are missing values? Or Should I exclude the classes that I don't use (and how if this is the only option)?</p>