title: Java: JSON -> Protobuf & back conversion
body: <p>I have an existing system, which is using <em>protobuf-based</em> communication protocol between GUI and server. Now I would like to add some persistence, but at the moment protobuf messages are straight converted to a third-party custom objects.</p>
  
  <p>Is there a way to convert <em>proto</em> messages to <em>json</em>, which could be then persisted to database.</p>
  
  <p><strong>N.B.:</strong> I don't much like an idea of writing binary protobuf to database, because it can one day become not backward-compatible with newer versions and break the system that way.</p>