// Writing
AddressBookProtos.Person.Builder personBuilder = AddressBookProtos.Person.newBuilder();
personBuilder.setId(1);
personBuilder.setName("Galder Zamarreño");
personBuilder.setEmail("galder@galder.com");
AddressBookProtos.Person person = personBuilder.build();
hotRodClient.put("me", person);

// Writing marshaller
public byte[] objectToByteBuffer(Object o) throws Exception {
  ByteArrayOutputStream baos = new ByteArrayOutputStream();
  Message message = (Message) o;
  byte[] name = message.getDescriptorForType().getFullName().getBytes("UTF-8");
  baos.write(name.length); // TODO: Send length as int and not byte
  baos.write(name);
  byte[] messageBytes = message.toByteArray();
  baos.write(messageBytes.length); // TODO: Send length as int and not byte
  baos.write(messageBytes);
  return baos.toByteArray();
}

// Reading marshaller
public Object objectFromByteBuffer(byte[] buffer) throws Exception {
   ByteArrayInputStream bais = new ByteArrayInputStream(buffer);
   byte[] name = new byte[bais.read()];
   bais.read(name); // TODO: Read fully??
   String className = mapping.get(new String(name, "UTF-8"));
   Class clazz = Thread.currentThread().getContextClassLoader().loadClass(className);
   Method parseFromMethod = clazz.getMethod("parseFrom", byte[].class);
   byte[] message = new byte[bais.read()];
   bais.read(message); // TODO: Read fully??
   return parseFromMethod.invoke(null, message);
}

// Mapping of proto language descriptor name and class name shown below:
FileDescriptorSet descriptorSet = FileDescriptorSet.parseFrom(new FileInputStream("src/main/desc/addressbook.desc"));
for (FileDescriptorProto fdp: descriptorSet.getFileList()) {
   FileDescriptor fd = FileDescriptor.buildFrom(fdp, new FileDescriptor[]{});
   for(Descriptor descriptor : fd.getMessageTypes()) {
      String className = fdp.getOptions().getJavaPackage() + "." + fdp.getOptions().getJavaOuterClassname() + "$" + descriptor.getName();
      mapping.put(descriptor.getFullName(), className);
    }
}

// Reading
AddressBookProtos.Person person = hotRodClient.get("me");