Dynamic parsing of .proto text file at runtime to generate descriptors

Question

I am currently working on Google Protocol Buffers and need to generate dynamic messages. I already have my .proto files defined as shown below.

message TSInbound
{
  string id = 1;
  map<string,string> state = 2;
  map<string,string> reading =3;
}

AFAIK,I can use File Descriptor Set to create dynamic messsages. But, that would involve using the compiler to generate the desc files. I would like to generate Descriptor without compiling the .proto files. Is there a way for dynamic creation of message using custom defined .proto files and not using protoc ?

score 7 · Accepted Answer · answered Mar 18 '16 at 17:40

7

I think you are asking: "Is there a way to dynamically parse text .proto files at runtime to get descriptors."

The .proto parser is written in C++. It is available as the library libprotoc.so. You could, in theory, write a JNI wrapper around this to do parsing at runtime. However, there is no (official) pure-Java parser for .proto files.

answered Mar 18 '16 at 17:40

Kenton Varda

41,353
8
121
105

Yes,@kenton Varda that is what I precisely want to do. Thanks for your suggestion – Ankita Mar 18 '16 at 18:19
@Ankita Did you find any solution for the above problem? – Prog_G Sep 14 '20 at 07:50

score 0 · Answer 2 · answered May 04 '23 at 22:02

I just found a solution from confluent, more precisely 'io.confluent:kafka-protobuf-serializer', which enables this in a very easy way

    ProtobufSchema schema = new ProtobufSchema(
            Files.readString(
                    Path.of("/anyPath/test.proto")
            )
    );
    Descriptor descriptor = schema.toDescriptor();
    Message deserializedMessage = DynamicMessage.parseFrom(descriptor, messageByteArr);

Dynamic parsing of .proto text file at runtime to generate descriptors

2 Answers2