The protocol buffer file of the employee example

employee.proto

syntax = "proto2";
// there's also "proto3"

package employeebook;

option java_package = "com.cnb.employeebook";
option java_outer_classname = "EmployeeBookProtos";

message Employee {
  required string name = 1;
  required int32 id = 2;
  optional string email = 3;
  optional string position = 4;

  enum PhoneType {
    WORK = 0;
    MOBILE = 1;
  }

  message PhoneNumber {
    required string number = 1;
    optional PhoneType type = 2 [default = WORK];
  }

  repeated PhoneNumber phones = 5;
}

message EmployeeBook {
  repeated Employee employees = 1;
}