title: Implementation provided for BatchConfigurer is not connsidered when using @EnableBatchProcessing(modular=true)
body: <p>I am developing a sample application that Spring Batch with Spring Boot. My requirement is: </p>
  
  <ul>
  <li><p>Have my own implementation of <code>BasicBatchConfigurer</code> so that I can configure AsyncTaskExecutor and my own dataSource as I am using SAP HANA as DB for which databaseType is not supported.</p></li>
  <li><p>I want to use <code>@EnableBatchProcessing(modular=true)</code> so that I can register multiple jobs and launch them with separate Child Context</p></li>
  </ul>
  
  <p>I have added all the required configurations. Without setting modular=true the Job is Launched and works as expected. It initializes the beans defined from my implementation of BasicBatchConfigurer.</p>
  
  <p>However, once modular=true is set, the beans from my implementation are not initialized.</p>
  
  <p>The code is hosted here: <a href="https://github.com/VKJEY/spring-framework-evaluation" rel="nofollow noreferrer">https://github.com/VKJEY/spring-framework-evaluation</a></p>
  
  <p>I debugged further into the issue: </p>
  
  <ul>
  <li>Looks like, When we set modular=true, <code>BatchConfigurationSelector</code> uses ModularBatchConfiguration </li>
  <li>In ModularBatchConfiguration, there's a field  <code>Collection&lt;BatchConfigurer&gt; configurers</code>. This has been annotated as <code>@autowired</code>.</li>
  <li>I assume that this field is auto initialized if I provided a implementation
  of <code>BatchConfigurer</code> as it has been mentioned in the comments of <code>ModularBatchConfiguration</code> class as well</li>
  <li>However, While debugging I realized that the above field is still null beacuse of which, It loads <code>DefaultBatchConfigurer</code> and follows the default flow. </li>
  </ul>
  
  <p>My question is why is that field <code>configurers</code> not being initialized in <code>ModularBatchConfiguration</code>? Am I missing something?</p>
  
  <p>I am using Spring boot 2.1.2. </p>