title: What is best way of injecting values from environment variables?
body: <p>Consider this example  </p>
  
  <pre><code>@Stateless
  public class UniqueIdGenerator {
      private static final String COLON = ":";
      private String serverPrivateKey;
  
      @SuppressWarnings("UnusedDeclaration")
      public UniqueIdGenerator() {
      }
  
      @Inject
      public UniqueIdGenerator(@Nonnull final String serverPrivateKey) {
          this.serverPrivateKey = serverPrivateKey;
      }
      ...
  }
  </code></pre>
  
  <p>I would like to <code>@Inject</code> value of <code>serverPrivateKey</code> based on an environment variable available in different environments. </p>
  
  <p>What is the best way to inject it here?</p>