package lm; 
message helloworld 
{ 
   required int32     id = 1;  // ID 
   required string    str = 2;  // str 
   optional int32     opt = 3;  //optional field 
}

packageName.MessageName.proto

# pbjs <filename> [options] [> outFile]
我们来看看options:

  --help, -h        Show help  [boolean] 查看帮助
  --version, -v     Show version number  [boolean] 查看版本号
  --source, -s      Specifies the source format. Valid formats are:

                       json       Plain JSON descriptor
                       proto      Plain .proto descriptor
指定来源文件格式，可以是json或proto文件。

  --target, -t      Specifies the target format. Valid formats are:

                       amd        Runtime structures as AMD module
                       commonjs   Runtime structures as CommonJS module
                       js         Runtime structures
                       json       Plain JSON descriptor
                       proto      Plain .proto descriptor
指定生成文件格式，可以是符合amd或者commonjs规范的js文件，或者是单纯的js/json/proto文件。

  --using, -u       Specifies an option to apply to the volatile builder
                    loading the source, e.g. convertFieldsToCamelCase.
  --min, -m         Minifies the output.  [default: false] 压缩生成文件
  --path, -p        Adds a directory to the include path.
  --legacy, -l      Includes legacy descriptors from google/protobuf/ if
                    explicitly referenced.  [default: false]
  --quiet, -q       Suppresses any informatory output to stderr.  [default: false]
  --use, -i         Specifies an option to apply to the emitted builder
                    utilized by your program, e.g. populateAccessors.
  --exports, -e     Specifies the namespace to export. Defaults to export
                    the root namespace.
  --dependency, -d  Library dependency to use when generating classes.
                    Defaults to 'protobufjs' for CommonJS, 'ProtoBuf' for
                    AMD modules and 'dcodeIO.ProtoBuf' for classes.

# ./pbjs ../../lm.message.proto  -t commonjs > ../../lm.message.js

module.exports = require("protobufjs").newBuilder({})['import']({
    "package": "lm",
    "messages": [
        {
            "name": "helloworld",
            "fields": [
                {
                    "rule": "required",
                    "type": "int32",
                    "name": "id",
                    "id": 1
                },
                {
                    "rule": "required",
                    "type": "string",
                    "name": "str",
                    "id": 2
                },
                {
                    "rule": "optional",
                    "type": "int32",
                    "name": "opt",
                    "id": 3
                }
            ]
        }
    ]
}).build();

var HelloWorld = require('./lm.helloworld.js')['lm']['helloworld'];
var fs = require('fs');

// 除了这种传入一个对象的方式， 你也可以使用get/set 函数用来修改和读取结构化数据中的数据成员
var hw = new HelloWorld({
    'id': 101,
    'str': 'Hello'
})

var buffer = hw.encode();

fs.writeFile('./test.log', buffer.toBuffer(), function(err) {
    if(!err) {
        console.log('done!');
    }
});

var HelloWorld = require('./lm.helloworld.js')['lm']['helloworld'];
var fs = require('fs');

var buffer = fs.readFile('./test.log', function(err, data) {
    if(!err) {
        console.log(data); // 来看看Node里的Buffer对象长什么样子。
        var message = HelloWorld.decode(data);
        console.log(message);
    }
})

package cover;

message helloworld {

    message helloCoverReq {
        required string name = 1;
    }

    message helloCoverRsp {
        required int32 retcode = 1;
        optional string reply = 2;
    }
}

var dgram = require('dgram');
var ProtoBuf = require("protobufjs");
var PORT = 33333;
var HOST = '127.0.0.1';

var builder = ProtoBuf.loadProtoFile("./cover.helloworld.proto"),
    Cover = builder.build("cover"),
    HelloCoverReq = Cover.helloworld.helloCoverReq;
    HelloCoverRsp = Cover.helloworld.helloCoverRsp;

var hCReq = new HelloCoverReq({
    name: 'R U coverguo?'
})


var buffer = hCReq.encode();

var socket = dgram.createSocket({
    type: 'udp4',
    fd: 8080
}, function(err, message) {
    if(err) {
        console.log(err);
    }

    console.log(message);
});

var message = buffer.toBuffer();

socket.send(message, 0, message.length, PORT, HOST, function(err, bytes) {
    if(err) {
        throw err;
    }

    console.log('UDP message sent to ' + HOST +':'+ PORT);
});

socket.on("message", function (msg, rinfo) {
    console.log("[UDP-CLIENT] Received message: " + HelloCoverRsp.decode(msg).reply + " from " + rinfo.address + ":" + rinfo.port);
    console.log(HelloCoverRsp.decode(msg));

    socket.close();

    //udpSocket = null;
});

socket.on('close', function(){
    console.log('socket closed.');


});

socket.on('error', function(err){
    socket.close();

    console.log('socket err');
    console.log(err);
});

var PORT = 33333;
var HOST = '127.0.0.1';
var ProtoBuf = require("protobufjs");
var dgram = require('dgram');
var server = dgram.createSocket('udp4');

var builder = ProtoBuf.loadProtoFile("./cover.helloworld.proto"),
    Cover = builder.build("cover"),
    HelloCoverReq = Cover.helloworld.helloCoverReq;
    HelloCoverRsp = Cover.helloworld.helloCoverRsp;

server.on('listening', function () {
    var address = server.address();
    console.log('UDP Server listening on ' + address.address + ":" + address.port);
});

server.on('message', function (message, remote) {
    console.log(remote.address + ':' + remote.port +' - ' + message);
    console.log(HelloCoverReq.decode(message) + 'from client!');
    var hCRsp = new HelloCoverRsp({
        retcode: 0,
        reply: 'Yeah!I\'m handsome cover!'
    })

    var buffer = hCRsp.encode();
    var message = buffer.toBuffer();
    server.send(message, 0, message.length, remote.port, remote.address, function(err, bytes) {
        if(err) {
            throw err;
        }

        console.log('UDP message reply to ' + remote.address +':'+ remote.port);
    })

});

server.bind(PORT, HOST);

message Person { 
  required string name = 1; 
  required int32 id = 2;        // Unique ID number for this person. 
  optional string email = 3; 

  enum PhoneType { 
    MOBILE = 0; 
    HOME = 1; 
    WORK = 2; 
  } 

  message PhoneNumber { 
    required string number = 1; 
    optional PhoneType type = 2 [default = HOME]; 
  } 
  repeated PhoneNumber phone = 4; 
 }

import common.header; 

 message youMsg{ 
  required common.info_header header = 1; 
  required string youPrivateData = 2; 
 }

08 65 12 06 48 65 6C 6C 6F 77

31 30 31 3C 2F 69 64 3E 3C 6E 61 6D 65 3E 68 65 
 6C 6C 6F 3C 2F 6E 61 6D 65 3E 3C 2F 68 65 6C 6C 
 6F 77 6F 72 6C 64 3E

 <helloworld> 
    <id>101</id> 
    <name>hello</name> 
 </helloworld>