core.clj

(ns protobuf-exp.core
  (:require [flatland.protobuf.core :as pb])
  (:import pi.Pages$Page))

(def Page (pb/protodef Pages$Page))
(def p (pb/protobuf Page :id 1 :url "http://blah.com" :description "I am a protobuf"))

(defn write-to-file [proto path]
  (with-open [myout (clojure.java.io/output-stream path)]
    (.write myout (pb/protobuf-dump proto))))

(defn load-from-file [path]
  (with-open [stream (clojure.java.io/input-stream path)]
    (pb/protobuf-load-stream Page stream)))

(comment
  (assoc p :classified :CLASSIFIED)
#_=> {:classified :classified,
      :description "I am a protobuf",
      :id 1,
      :url "http://blah.com"}
)

pages.proto

package pi;

message Page {
  required int32 id = 1;
  required string url = 2;
  required string description = 3;
  repeated string keywords = 5;
  optional float price = 6;

  enum ClassifiedType {
    CLASSIFIED = 0;
    NOT_CLASSIFIED = 1;
    UNCLASSIFIABLE = 2;
  }

  optional ClassifiedType classified = 4 [default = NOT_CLASSIFIED];
}