title: Examining a protobuf message - how to get field values by name?
body: <p>I seem unable to find a way to verify the value of a field inside a protobuf message without explicitly invoking its getter.</p>
  
  <p>I see examples around that make usage of <code>Descriptors.FieldDescriptor</code> instances to reach inside the message map, but they are either iterator-based or driven by field number.</p>
  
  <p>Once I have the map:</p>
  
  <pre><code>Map&lt;Descriptors.FieldDescriptor, Object&gt; allFields = myMsg.getAllFields();
  </code></pre>
  
  <p>how can I get the value of field <code>"fieldXyz"</code>?</p>
  
  <p>I know that I can use <code>myMsg.getFieldXyz()</code>, but this is not usable in a systematic way.</p>
  
  <p>If there is no way to access field values by their names, I'd like to know what is the rationale behind this choice. I may have still to understand the protobuf "philosophy" :-)</p>