To generate Message Java classes, you need to install the protoc binary.
This converter supports by default "application/x-protobuf" and "text/plain"
with the official "com.google.protobuf:protobuf-java" library. Other formats can be
supported with one of the following additional libraries on the classpath:
"application/json", "application/xml", and "text/html" (write-only)
with the "com.googlecode.protobuf-java-format:protobuf-java-format" third-party library
Requires Protobuf 2.6 or higher (and Protobuf Java Format 1.4 or higher for formatting).
This converter will auto-adapt to Protobuf 3 and its default protobuf-java-util JSON
format if the Protobuf 2 based protobuf-java-format isn't present; however, for more
explicit JSON setup on Protobuf 3, consider ProtobufJsonFormatHttpMessageConverter.
Alex Antonov, Brian Clozel, Juergen Hoeller, Sebastien Deleuze