title: How to enable Eclipse auto-completion in application.yml for custom properties declared by @ConfigurationProperties?
body: <p>I made a simple class with configuration properties for my spring-boot project. Everything work as a charm (spring-boot catches options) except the fact that Eclipse doesn't recognize new properties as valid options in <strong>application.yml</strong> and highlights them as unknown. </p>
  
  <p>Here is the class:</p>
  
  <pre class="lang-java prettyprint-override"><code>@Component
  @ConfigurationProperties(prefix="server")
  public class ServerProperties {
      private Integer delay;
      private DataAdapter dataAdapter = new DataAdapter();
      // setters and getters were cut out for the sake of readability 
  
      public static class DataAdapter {
          private String baseUrl;
          private String targetCode;
          // setters and getters 
      }
  }
  </code></pre>
  
  <p>Autocompletion does not work for those properties:</p>
  
  <p><img src="https://i.stack.imgur.com/M01J3.jpg" alt="Autocompletion does not work for those properties"></p>
  
  <p>I added the dependency for Spring Boot Configuration Processor to <strong>pom.xml</strong> as recommended in <a href="https://docs.spring.io/spring-boot/docs/current/reference/html/configuration-metadata.html#configuration-metadata-annotation-processor" rel="nofollow noreferrer">Spring.io reference</a>, but it does not work as supposed. </p>
  
  <pre class="lang-xml prettyprint-override"><code>    &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-configuration-processor&lt;/artifactId&gt;
          &lt;optional&gt;true&lt;/optional&gt;
      &lt;/dependency&gt;
  </code></pre>
  
  <p>Tried to switch to <em>application.properties</em> but autocompletion still doesn't work.</p>