title: How to use ElasticsearchEntityMapper if entity index is time based?
body: <p>As we know, every entity of ElasticsearchEntityMapper requires annotation </p>
  
  <pre><code>@Document(indexName="foo")
  public class Foo {...}
  </code></pre>
  
  <p>, so that we can use convenient methods, like:</p>
  
  <pre><code>&lt;T&gt; Page&lt;T&gt; queryForPage(SearchQuery query, Foo.class);
  </code></pre>
  
  <p>But it is very common, that the indices of elasticsearch were designed time-based or language-based. i.e.</p>
  
  <pre><code>@Document(indexName="2019")
  public class Foo {...}
  
  @Document(indexName="2020")
  public class Foo {...}
  </code></pre>
  
  <p>or </p>
  
  <pre><code>@Document(indexName="english")
  public class Foo {...}
  
  @Document(indexName="german")
  public class Foo {...}
  </code></pre>
  
  <p>Of course, we can't create classes like this, <strong>one class with different indices</strong>. 
  What should we do in this case? One class each index, Foo2019, Foo2020? &lt;- Very bad idea.</p>
  
  <p>I am wondering, why does spring-data-elasticsearch design entity in this way? It's not really flexible. Or I misunderstand the usage?</p>
  
  <p>Thanks for your help in advance! :)</p>