There is no .proto parser in Java. However, you can use protoc's --descriptor_set_out flag to generate a FileDescriptorProto representing the file (or use FileDescriptor::CopyTo() in C++). This is a protocol buffer representation of everything defined in the .proto. In Java, you can then: 1) Parse the FileDescriptorProto. 2) Construct a FileDescriptor from it. 3) Use FindMessageTypeByName() on the FileDescriptor to get a Descriptor for the type you are interested in. 4) Construct a DynamicMessage from that.
On Wed, Oct 21, 2009 at 2:11 AM, TinCan <[email protected]> wrote: > > Hi, > My problem: > I am working on a Java application which is using protocol buffers to > communicate with an application written in C++. I've met some > challenges at the Java end, because I do not have the opportunity to > compile the .proto files into my Java app. > > At the C++ end we did not encounter any problems in parsing .proto > files and constructing protobuf messages (dynamic) at runtime. This > seems to be a little more tricky at the Java end. > > What I try to do: > The C++ application is using protocol buffers for internal > communication. This works like a charm, and we are very happy with the > decision of using this API. > Now I have been working on a service application which is supposed to > display protocol buffer data dynamically using reflection. The C++ > application will send .proto descriptions and protobuf data via an UDP > connection to the Java application. > > My question: > I understand that there is not a .proto file parser available for > Java. Is this correct? > If so: How can I construct a message dynamically in a Java > application? > > I've been looking at the classes DynamicMessage, Descriptor, > DescriptorProto and others (including their Builders). But I am > struggling to figure out how they are related, and how to use them > correctly. > > Can anyone please help me with more documentation, or a working > example on how to create a protobuf message (dynamically)? > > Regards > Ole > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~----------~----~----~----~------~----~------~--~---
