title: filter document in mongo
body: <p>We have a collection of employees: </p>
  
  <pre><code>// Sample document.
          Document emp2 = new Document();
          emp2.put("name", "Charlotte Neil");
          emp2.put("website", "webcodegeeks.com");
  
          Document emp2_addr = new Document();
          emp2_addr.put("addr_line1", "Fremont, AK");
          emp2_addr.put("zip_code", "19408");
          emp2.put("address", emp2_addr);
  </code></pre>
  
  <p>The below filter is not working:</p>
  
  <pre><code>AggregateIterable&lt;Document&gt; documents = collection.aggregate(Arrays.asList(
                  new Document("$match", Document.parse("{ \"name\": \"Charlotte.*\" }")) 
          ));
  </code></pre>
  
  <p>What is the correct syntax to filter the above?<br>
  Help is appreciated.</p>