node.js - 使用 Node.js 的 AMQP，如何发布/订阅？

Question

我正在创建一个操作 Node-AMQP 模块的类:https://github.com/postwait/node-amqp

但我无法使用此发布/订阅:

  var Queue = require('./Queue.js');
  var queue = new Queue();
  queue.addTaskToQueue('salut', 5);
  queue.subscribeTaskQueue('salut');

这是我正在使用的类(我为那些不了解 CoffeeScript 的人提供了 CoffeeScript 中的代码，以及 Node.js 中的代码):

感谢您的帮助。

在 CoffeeScript 中:

amqp = require('amqp')

class Queue

    constructor: (ip = 'localhost') ->
            @ip = ip
            @receivedObject
            @connection = amqp.createConnection({ host: @ip })
            @queue

    subscribeTaskQueue: (queueToSubscribe) ->
            self = @
            self.connection.on('ready', ->
                    q = self.connection.queue(queueToSubscribe)
                    q.bind('#')

                    q.subscribe({ ack: true }, (message) ->
                            self.receivedObject = message
                            console.log(self.receivedObject)
                    )
            )

    addTaskToQueue: (queue, objectToSend) ->
            @queue = @connection.queue("salut", { durable: true })
            @connection.publish(queue, objectToSend)

module.exports = Queue

在 Node.js 中

(function() {
  var Queue, amqp;
  amqp = require('amqp');
  Queue = (function() {
    function Queue(ip) {
      if (ip == null) {
        ip = 'localhost';
      }
      this.ip = ip;
      this.receivedObject;
      this.connection = amqp.createConnection({
        host: this.ip
      });
      this.queue;
    }
    Queue.prototype.subscribeTaskQueue = function(queueToSubscribe) {
      var self;
      self = this;
      return self.connection.on('ready', function() {
        var q;
        q = self.connection.queue(queueToSubscribe);
        q.bind('#');
        return q.subscribe({
          ack: true
        }, function(message) {
          self.receivedObject = message;
          return console.log(self.receivedObject);
        });
      });
    };
    Queue.prototype.addTaskToQueue = function(queue, objectToSend) {
      this.queue = this.connection.queue("salut", {
        durable: true
      });
      return this.connection.publish(queue, objectToSend);
    };
    return Queue;
  })();
  module.exports = Queue;
}).call(this);

<小时/>

我按照你说的做了+我做了一些修改。

这是我的类 Queue.coffee :

amqp = require('amqp')

class Queue

    constructor: (ip = "localhost", queueName = "salut") ->
            @ip = ip
            @receivedObject = "test"
            @connection = amqp.createConnection({ host: 'localhost' })
            @queueName = queueName

    subscribeTaskQueue: () ->
            @connection.on('ready', ->
                    q = @connection.queue(@queueName)
                    q.bind('#')

                    q.subscribe({ ack: true }, (message) ->
                            @receivedObject = message
                            console.log(@receivedObject)
                    )
            )

    addTaskToQueue: (objectToSend = "hello") ->
            @connection.publish(@queueName, objectToSend)


queue = new Queue("localhost", "salut")

queue.connection.on 'ready', ->
  queue.addTaskToQueue 'salut', 5
  queue.subscribeTaskQueue 'salut'

这是rabbituser.coffee:

Queue = require('./Queue.js')
queue = new Queue("localhost", "salut")

queue.addTaskToQueue("hello")
queue.subscribeTaskQueue()

当我执行命令时:noderabbituser.js

我明白了:

node.js:134
        throw e; // process.nextTick error, or 'error' event on first tick
        ^
TypeError: Cannot read property '' of undefined
    at Connection.exchange (/home/armand/node_modules/amqp/amqp.js:1242:21)
    at Connection.publish (/home/armand/node_modules/amqp/amqp.js:1258:60)
    at Queue.addTaskToQueue (/home/armand/Desktop/RockSolidProject/coucheAMQP/Queue.js:36:30)
    at Object.<anonymous> (/home/armand/Desktop/RockSolidProject/coucheAMQP/rabbituser.js:5:9)
    at Object.<anonymous> (/home/armand/Desktop/RockSolidProject/coucheAMQP/rabbituser.js:7:4)
    at Module._compile (module.js:402:26)
    at Object..js (module.js:408:10)
    at Module.load (module.js:334:31)
    at Function._load (module.js:293:12)
    at Array.<anonymous> (module.js:421:10)

Answer 1

我不确定您遇到的错误是什么，但我会指出一些事情:

1. 在构造函数中，当您编写 @receivedObject 时和@queue ——那没有任何作用。在 JavaScript 中，每个对象都是一个哈希，您可以随时附加属性；如果@receivedObject和@queue最初在 Queue 中未定义实例，那么您不必在构造函数中定义它们。

2. 问题是否有可能是您正在调用 @connection.queue在addTaskToQueue在连接存在之前(即 self.connection.on 'ready' 回调之前)？

也许如果您将代码更改为

queue = new Queue()
queue.connection.on 'ready', ->
  queue.addTaskToQueue 'salut', 5
  queue.subscribeTaskQueue 'salut'

如果这不能解决您的问题，能否请您准确描述您遇到的错误以及遇到该错误的位置？