sbt-cppp (Sbt Cross-Project Protobuf Plugin) is a Sbt plugin to support Protocol Buffers, especially in multi-project builds.

sbt-cppp compiles *.proto into .java files. In addition, sbt-cppp provides some features missed in sbt-protobuf or other protobuf plugins:

• Jar packaging from .proto files.
• Cross-project protoc include path dependency management in multi-project builds.
• Cross-library protoc include path dependency management by auto-unzipping .proto files from jar packages.
• Support for custom code generator to .proto files.

Add the following line to your project/plugins.sbt:

addSbtPlugin("com.dongxiguo" % "sbt-cppp" % "0.1.4")

And add protobufSettings and protobuf-java dependency to your build.sbt:

protobufSettings

libraryDependencies += "com.google.protobuf" % "protobuf-java" % "2.5.0"

For windows, download at http://code.google.com/p/protobuf/downloads/detail?name=protoc-2.5.0-win32.zip. For most linux distributions, look for protobuf-compiler package.

Create src/protobuf/sample_proto.proto

message SampleMessage {
  optional int32 sample_field = 1;
}

Create src/main/scala/SampleMain.scala:

object SampleMain {
  def main(args: Array[String]) {
    println(SampleMessage.newBuilder.setSampleField(123).build)
  }
}

$ sbt
> run-main SampleMain

• sbt-cppp is for sbt 0.12 or 0.13
• If project-foo depends on project-bar, project-bar/src/protobuf/ will be added as a protoc include path when the plugin converts project-foo/src/protobuf/*.proto into .java files.
• If you want to generate .proto files by some tools (instead of creating them manually), put sourceGenerators in Protobuf += yourGenerator in your build.sbt.