Is anyone familiar with a stable C++ solution (library, code snippet etc.) which converts protobuf messages to/from JSON?
This one is better IMO: https://github.com/shramov/json2pb
it does conversion in both directions and handles extensions
I've made a bootstrap implementation of a JSON parser for protobuf generated types, using the its reflection mechanism, and adapting the parse I've made previously for CORBA IDL generated types.
You can find it at http://corbasim.googlecode.com/svn/trunk/protobuf2json_exported.zip
By this way for each protobuf defined message, you will be able to parse its instances by doing:
Foo foo;
const std::string json_foo = "{\"text\": \"Hello world\"}";
protobuf2json::json::parse(foo, json_foo);
It's just an initial implementation, and it just support string fields, but it's easy to implement all kind of fields.
pbjson is another one, which built on rapidjson, maybe faster.
pb2json is another C++ library that can do this.
来源：https://stackoverflow.com/questions/7007876/c-protobuf-to-from-json-conversion