如何使用Eclipse Paho JavaScript客户端连接到test.mosquitto.org

Question

我是物联网世界的新手，一直很困惑为什么我不能使用Eclipse Paho JavaScript客户端连接到test.mosquitto.org。

正如其他paho mqtt问题中所建议的那样，我使用了Port:8080和Path:/mqtt，但在使用这个Eclipse web客户端时遇到了Failed to connect: AMQJS0007E Socket error:undefined。

我已经使用了HiveMQ WebClient，并且能够连接、发布和订阅test.mosquitto.org(端口8080)和iot.eclipse.org(端口443)。

我注意到，与Paho Eclipse的paho-mqtt.js相比，HiveMQ源mqttws31.js，但不确定其意义。

我想说这个问题有两个部分：

1. 要让Eclipse Paho JavaScript客户端连接到test.mosquitto.org，我缺少什么？

2. mqttws31.js和paho-mqtt.js之间的区别是什么？与另一个相比，它们可以相对轻松地连接到test.mosquitto.org？

谢谢！

---

相关代码：

下面的代码直接取自https://www.eclipse.org/paho/clients/js/utility/

paho mqtt.js：https://www.eclipse.org/paho/js/paho-mqtt.js

utility.js(处理按钮回调)：

/*******************************************************************************
* Copyright (c) 2015 IBM Corp.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
*
* The Eclipse Public License is available at
*    http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
*   http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
*    James Sutton - Initial Contribution
*******************************************************************************/
/*
Eclipse Paho MQTT-JS Utility
This utility can be used to test the Eclipse Paho MQTT Javascript client.
*/
// Create a client instance
var client = null;
var connected = false;

logMessage("INFO", "Starting Eclipse Paho JavaScript Utility.");
// Things to do as soon as the page loads
document.getElementById("clientIdInput").value = "js-utility-" + makeid();
// called when the client connects
function onConnect(context) {
// Once a connection has been made, make a subscription and send a message.
var connectionString = context.invocationContext.host + ":" + context.invocationContext.port + context.invocationContext.path;
logMessage("INFO", "Connection Success ", "[URI: ", connectionString, ", ID: ", context.invocationContext.clientId, "]");
var statusSpan = document.getElementById("connectionStatus");
statusSpan.innerHTML = "Connected to: " + connectionString + " as " + context.invocationContext.clientId;
connected = true;
setFormEnabledState(true);
}

function onConnected(reconnect, uri) {
// Once a connection has been made, make a subscription and send a message.
logMessage("INFO", "Client Has now connected: [Reconnected: ", reconnect, ", URI: ", uri, "]");
connected = true;

}
function onFail(context) {
logMessage("ERROR", "Failed to connect. [Error Message: ", context.errorMessage, "]");
var statusSpan = document.getElementById("connectionStatus");
statusSpan.innerHTML = "Failed to connect: " + context.errorMessage;
connected = false;
setFormEnabledState(false);
}
// called when the client loses its connection
function onConnectionLost(responseObject) {
if (responseObject.errorCode !== 0) {
logMessage("INFO", "Connection Lost. [Error Message: ", responseObject.errorMessage, "]");
}
connected = false;
}
// called when a message arrives
function onMessageArrived(message) {
logMessage("INFO", "Message Recieved: [Topic: ", message.destinationName, ", Payload: ", message.payloadString, ", QoS: ", message.qos, ", Retained: ", message.retained, ", Duplicate: ", message.duplicate, "]");
var messageTime = new Date().toISOString();
// Insert into History Table
var table = document.getElementById("incomingMessageTable").getElementsByTagName("tbody")[0];
var row = table.insertRow(0);
row.insertCell(0).innerHTML = message.destinationName;
row.insertCell(1).innerHTML = safeTagsRegex(message.payloadString);
row.insertCell(2).innerHTML = messageTime;
row.insertCell(3).innerHTML = message.qos;

if (!document.getElementById(message.destinationName)) {
var lastMessageTable = document.getElementById("lastMessageTable").getElementsByTagName("tbody")[0];
var newlastMessageRow = lastMessageTable.insertRow(0);
newlastMessageRow.id = message.destinationName;
newlastMessageRow.insertCell(0).innerHTML = message.destinationName;
newlastMessageRow.insertCell(1).innerHTML = safeTagsRegex(message.payloadString);
newlastMessageRow.insertCell(2).innerHTML = messageTime;
newlastMessageRow.insertCell(3).innerHTML = message.qos;
} else {
// Update Last Message Table
var lastMessageRow = document.getElementById(message.destinationName);
lastMessageRow.id = message.destinationName;
lastMessageRow.cells[0].innerHTML = message.destinationName;
lastMessageRow.cells[1].innerHTML = safeTagsRegex(message.payloadString);
lastMessageRow.cells[2].innerHTML = messageTime;
lastMessageRow.cells[3].innerHTML = message.qos;
}
}
function connectionToggle() {
if (connected) {
disconnect();
} else {
connect();
}

}

function connect() {
var hostname = document.getElementById("hostInput").value;
var port = document.getElementById("portInput").value;
var clientId = document.getElementById("clientIdInput").value;
var path = document.getElementById("pathInput").value;
var user = document.getElementById("userInput").value;
var pass = document.getElementById("passInput").value;
var keepAlive = Number(document.getElementById("keepAliveInput").value);
var timeout = Number(document.getElementById("timeoutInput").value);
var tls = document.getElementById("tlsInput").checked;
var automaticReconnect = document.getElementById("automaticReconnectInput").checked;
var cleanSession = document.getElementById("cleanSessionInput").checked;
var lastWillTopic = document.getElementById("lwtInput").value;
var lastWillQos = Number(document.getElementById("lwQosInput").value);
var lastWillRetain = document.getElementById("lwRetainInput").checked;
var lastWillMessageVal = document.getElementById("lwMInput").value;

if (path.length > 0) {
client = new Paho.Client(hostname, Number(port), path, clientId);
} else {
client = new Paho.Client(hostname, Number(port), clientId);
}
logMessage("INFO", "Connecting to Server: [Host: ", hostname, ", Port: ", port, ", Path: ", client.path, ", ID: ", clientId, "]");
// set callback handlers
client.onConnectionLost = onConnectionLost;
client.onMessageArrived = onMessageArrived;
client.onConnected = onConnected;

var options = {
invocationContext: { host: hostname, port: port, path: client.path, clientId: clientId },
timeout: timeout,
keepAliveInterval: keepAlive,
cleanSession: cleanSession,
useSSL: tls,
reconnect: automaticReconnect,
onSuccess: onConnect,
onFailure: onFail
};

if (user.length > 0) {
options.userName = user;
}
if (pass.length > 0) {
options.password = pass;
}
if (lastWillTopic.length > 0) {
var lastWillMessage = new Paho.Message(lastWillMessageVal);
lastWillMessage.destinationName = lastWillTopic;
lastWillMessage.qos = lastWillQos;
lastWillMessage.retained = lastWillRetain;
options.willMessage = lastWillMessage;
}
// connect the client
client.connect(options);
var statusSpan = document.getElementById("connectionStatus");
statusSpan.innerHTML = "Connecting...";
}
function disconnect() {
logMessage("INFO", "Disconnecting from Server.");
client.disconnect();
var statusSpan = document.getElementById("connectionStatus");
statusSpan.innerHTML = "Connection - Disconnected.";
connected = false;
setFormEnabledState(false);
}
// Sets various form controls to either enabled or disabled
function setFormEnabledState(enabled) {
// Connection Panel Elements
if (enabled) {
document.getElementById("clientConnectButton").innerHTML = "Disconnect";
} else {
document.getElementById("clientConnectButton").innerHTML = "Connect";
}
document.getElementById("hostInput").disabled = enabled;
document.getElementById("portInput").disabled = enabled;
document.getElementById("clientIdInput").disabled = enabled;
document.getElementById("pathInput").disabled = enabled;
document.getElementById("userInput").disabled = enabled;
document.getElementById("passInput").disabled = enabled;
document.getElementById("keepAliveInput").disabled = enabled;
document.getElementById("timeoutInput").disabled = enabled;
document.getElementById("tlsInput").disabled = enabled;
document.getElementById("automaticReconnectInput").disabled = enabled;
document.getElementById("cleanSessionInput").disabled = enabled;
document.getElementById("lwtInput").disabled = enabled;
document.getElementById("lwQosInput").disabled = enabled;
document.getElementById("lwRetainInput").disabled = enabled;
document.getElementById("lwMInput").disabled = enabled;
// Publish Panel Elements
document.getElementById("publishTopicInput").disabled = !enabled;
document.getElementById("publishQosInput").disabled = !enabled;
document.getElementById("publishMessageInput").disabled = !enabled;
document.getElementById("publishButton").disabled = !enabled;
document.getElementById("publishRetainInput").disabled = !enabled;
// Subscription Panel Elements
document.getElementById("subscribeTopicInput").disabled = !enabled;
document.getElementById("subscribeQosInput").disabled = !enabled;
document.getElementById("subscribeButton").disabled = !enabled;
document.getElementById("unsubscribeButton").disabled = !enabled;
}
function publish() {
var topic = document.getElementById("publishTopicInput").value;
var qos = document.getElementById("publishQosInput").value;
var message = document.getElementById("publishMessageInput").value;
var retain = document.getElementById("publishRetainInput").checked;
logMessage("INFO", "Publishing Message: [Topic: ", topic, ", Payload: ", message, ", QoS: ", qos, ", Retain: ", retain, "]");
message = new Paho.Message(message);
message.destinationName = topic;
message.qos = Number(qos);
message.retained = retain;
client.send(message);
}

function subscribe() {
var topic = document.getElementById("subscribeTopicInput").value;
var qos = document.getElementById("subscribeQosInput").value;
logMessage("INFO", "Subscribing to: [Topic: ", topic, ", QoS: ", qos, "]");
client.subscribe(topic, { qos: Number(qos) });
}
function unsubscribe() {
var topic = document.getElementById("subscribeTopicInput").value;
logMessage("INFO", "Unsubscribing: [Topic: ", topic, "]");
client.unsubscribe(topic, {
onSuccess: unsubscribeSuccess,
onFailure: unsubscribeFailure,
invocationContext: { topic: topic }
});
}

function unsubscribeSuccess(context) {
logMessage("INFO", "Unsubscribed. [Topic: ", context.invocationContext.topic, "]");
}
function unsubscribeFailure(context) {
logMessage("ERROR", "Failed to unsubscribe. [Topic: ", context.invocationContext.topic, ", Error: ", context.errorMessage, "]");
}
function clearHistory() {
var table = document.getElementById("incomingMessageTable");
//or use :  var table = document.all.tableid;
for (var i = table.rows.length - 1; i > 0; i--) {
table.deleteRow(i);
}
}

// Just in case someone sends html
function safeTagsRegex(str) {
return str.replace(/&/g, "&amp;").replace(/</g, "&lt;").
replace(/>/g, "&gt;");
}
function makeid() {
var text = "";
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
for (var i = 0; i < 5; i++)
text += possible.charAt(Math.floor(Math.random() * possible.length));
return text;
}
function logMessage(type, ...content) {
var consolePre = document.getElementById("consolePre");
var date = new Date();
var timeString = date.toUTCString();
var logMessage = timeString + " - " + type + " - " + content.join("");
consolePre.innerHTML += logMessage + "n";
if (type === "INFO") {
console.info(logMessage);
} else if (type === "ERROR") {
console.error(logMessage);
} else {
console.log(logMessage);
}
}

下面的代码直接取自http://www.hivemq.com/demos/websocket-client/

mqttws31.js：http://www.hivemq.com/demos/websocket-client/js/mqttws31.js

app.js(处理应用程序回调)：

/**
* Copyright 2013 dc-square GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @author: Christoph Schäbel
*/
var websocketclient = {
'client': null,
'lastMessageId': 1,
'lastSubId': 1,
'subscriptions': [],
'messages': [],
'connected': false,
'connect': function () {
var host = $('#urlInput').val();
var port = parseInt($('#portInput').val(), 10);
var clientId = $('#clientIdInput').val();
var username = $('#userInput').val();
var password = $('#pwInput').val();
var keepAlive = parseInt($('#keepAliveInput').val());
var cleanSession = $('#cleanSessionInput').is(':checked');
var lwTopic = $('#lwTopicInput').val();
var lwQos = parseInt($('#lwQosInput').val());
var lwRetain = $('#LWRInput').is(':checked');
var lwMessage = $('#LWMInput').val();
var ssl = $('#sslInput').is(':checked');
this.client = new Messaging.Client(host, port, clientId);
this.client.onConnectionLost = this.onConnectionLost;
this.client.onMessageArrived = this.onMessageArrived;
var options = {
timeout: 3,
keepAliveInterval: keepAlive,
cleanSession: cleanSession,
useSSL: ssl,
onSuccess: this.onConnect,
onFailure: this.onFail
};
if (username.length > 0) {
options.userName = username;
}
if (password.length > 0) {
options.password = password;
}
if (lwTopic.length > 0) {
var willmsg = new Messaging.Message(lwMessage);
willmsg.qos = lwQos;
willmsg.destinationName = lwTopic;
willmsg.retained = lwRetain;
options.willMessage = willmsg;
}
this.client.connect(options);
},
'onConnect': function () {
websocketclient.connected = true;
console.log("connected");
var body = $('body').addClass('connected').removeClass('notconnected').removeClass('connectionbroke');
websocketclient.render.hide('conni');
websocketclient.render.show('publish');
websocketclient.render.show('sub');
websocketclient.render.show('messages');
},
'onFail': function (message) {
websocketclient.connected = false;
console.log("error: " + message.errorMessage);
websocketclient.render.showError('Connect failed: ' + message.errorMessage);
},
'onConnectionLost': function (responseObject) {
websocketclient.connected = false;
if (responseObject.errorCode !== 0) {
console.log("onConnectionLost:" + responseObject.errorMessage);
}
$('body.connected').removeClass('connected').addClass('notconnected').addClass('connectionbroke');
websocketclient.render.show('conni');
websocketclient.render.hide('publish');
websocketclient.render.hide('sub');
websocketclient.render.hide('messages');
//Cleanup messages
websocketclient.messages = [];
websocketclient.render.clearMessages();
//Cleanup subscriptions
websocketclient.subscriptions = [];
websocketclient.render.clearSubscriptions();
},
'onMessageArrived': function (message) {
//        console.log("onMessageArrived:" + message.payloadString + " qos: " + message.qos);
var subscription = websocketclient.getSubscriptionForTopic(message.destinationName);
var messageObj = {
'topic': message.destinationName,
'retained': message.retained,
'qos': message.qos,
'payload': message.payloadString,
'timestamp': moment(),
'subscriptionId': subscription.id,
'color': websocketclient.getColorForSubscription(subscription.id)
};
console.log(messageObj);
messageObj.id = websocketclient.render.message(messageObj);
websocketclient.messages.push(messageObj);
},
'disconnect': function () {
this.client.disconnect();
},
'publish': function (topic, payload, qos, retain) {
if (!websocketclient.connected) {
websocketclient.render.showError("Not connected");
return false;
}
var message = new Messaging.Message(payload);
message.destinationName = topic;
message.qos = qos;
message.retained = retain;
this.client.send(message);
},
'subscribe': function (topic, qosNr, color) {
if (!websocketclient.connected) {
websocketclient.render.showError("Not connected");
return false;
}
if (topic.length < 1) {
websocketclient.render.showError("Topic cannot be empty");
return false;
}
if (_.find(this.subscriptions, { 'topic': topic })) {
websocketclient.render.showError('You are already subscribed to this topic');
return false;
}
this.client.subscribe(topic, {qos: qosNr});
if (color.length < 1) {
color = '999999';
}
var subscription = {'topic': topic, 'qos': qosNr, 'color': color};
subscription.id = websocketclient.render.subscription(subscription);
this.subscriptions.push(subscription);
return true;
},
'unsubscribe': function (id) {
var subs = _.find(websocketclient.subscriptions, {'id': id});
this.client.unsubscribe(subs.topic);
websocketclient.subscriptions = _.filter(websocketclient.subscriptions, function (item) {
return item.id != id;
});
websocketclient.render.removeSubscriptionsMessages(id);
},
'deleteSubscription': function (id) {
var elem = $("#sub" + id);
if (confirm('Are you sure ?')) {
elem.remove();
this.unsubscribe(id);
}
},
'getRandomColor': function () {
var r = (Math.round(Math.random() * 255)).toString(16);
var g = (Math.round(Math.random() * 255)).toString(16);
var b = (Math.round(Math.random() * 255)).toString(16);
return r + g + b;
},
'getSubscriptionForTopic': function (topic) {
var i;
for (i = 0; i < this.subscriptions.length; i++) {
if (this.compareTopics(topic, this.subscriptions[i].topic)) {
return this.subscriptions[i];
}
}
return false;
},
'getColorForPublishTopic': function (topic) {
var id = this.getSubscriptionForTopic(topic);
return this.getColorForSubscription(id);
},
'getColorForSubscription': function (id) {
try {
if (!id) {
return '99999';
}
var sub = _.find(this.subscriptions, { 'id': id });
if (!sub) {
return '999999';
} else {
return sub.color;
}
} catch (e) {
return '999999';
}
},
'compareTopics': function (topic, subTopic) {
var pattern = subTopic.replace("+", "(.*?)").replace("#", "(.*)");
var regex = new RegExp("^" + pattern + "$");
return regex.test(topic);
},
'render': {
'showError': function (message) {
alert(message);
},
'messages': function () {
websocketclient.render.clearMessages();
_.forEach(websocketclient.messages, function (message) {
message.id = websocketclient.render.message(message);
});
},
'message': function (message) {
var largest = websocketclient.lastMessageId++;
var html = '<li class="messLine id="' + largest + '">' +
'   <div class="row large-12 mess' + largest + '" style="border-left: solid 10px #' + message.color + '; ">' +
'       <div class="large-12 columns messageText">' +
'           <div class="large-3 columns date">' + message.timestamp.format("YYYY-MM-DD HH:mm:ss") + '</div>' +
'           <div class="large-5 columns topicM truncate" id="topicM' + largest + '" title="' + Encoder.htmlEncode(message.topic, 0) + '">Topic: ' + Encoder.htmlEncode(message.topic) + '</div>' +
'           <div class="large-2 columns qos">Qos: ' + message.qos + '</div>' +
'           <div class="large-2 columns retain">';
if (message.retained) {
html += 'Retained';
}
html += '           </div>' +
'           <div class="large-12 columns message break-words">' + Encoder.htmlEncode(message.payload) + '</div>' +
'       </div>' +
'   </div>' +
'</li>';
$("#messEdit").prepend(html);
return largest;
},
'subscriptions': function () {
websocketclient.render.clearSubscriptions();
_.forEach(websocketclient.subscriptions, function (subs) {
subs.id = websocketclient.render.subscription(subs);
});
},
'subscription': function (subscription) {
var largest = websocketclient.lastSubId++;
$("#innerEdit").append(
'<li class="subLine" id="sub' + largest + '">' +
'   <div class="row large-12 subs' + largest + '" style="border-left: solid 10px #' + subscription.color + '; background-color: #ffffff">' +
'       <div class="large-12 columns subText">' +
'           <div class="large-1 columns right closer">' +
'              <a href="#" onclick="websocketclient.deleteSubscription(' + largest + '); return false;">x</a>' +
'           </div>' +
'           <div class="qos">Qos: ' + subscription.qos + '</div>' +
'           <div class="topic truncate" id="topic' + largest + '" title="' + Encoder.htmlEncode(subscription.topic, 0) + '">' + Encoder.htmlEncode(subscription.topic) + '</div>' +
'       </div>' +
'   </div>' +
'</li>');
return largest;
},
'toggleAll': function () {
websocketclient.render.toggle('conni');
websocketclient.render.toggle('publish');
websocketclient.render.toggle('messages');
websocketclient.render.toggle('sub');
},
'toggle': function (name) {
$('.' + name + 'Arrow').toggleClass("closed");
$('.' + name + 'Top').toggleClass("closed");
var elem = $('#' + name + 'Main');
elem.slideToggle();
},
'hide': function (name) {
$('.' + name + 'Arrow').addClass("closed");
$('.' + name + 'Top').addClass("closed");
var elem = $('#' + name + 'Main');
elem.slideUp();
},
'show': function (name) {
$('.' + name + 'Arrow').removeClass("closed");
$('.' + name + 'Top').removeClass("closed");
var elem = $('#' + name + 'Main');
elem.slideDown();
},
'removeSubscriptionsMessages': function (id) {
websocketclient.messages = _.filter(websocketclient.messages, function (item) {
return item.subscriptionId != id;
});
websocketclient.render.messages();
},
'clearMessages': function () {
$("#messEdit").empty();
},
'clearSubscriptions': function () {
$("#innerEdit").empty();
}
}
};

---

Answer 1

我觉得我有点迟到了。。。但我把这里留给后人。

在1.0.3版本和1.1.0版本之前，Paho JS库经历了一系列的更改。

如果您引用的是mqttws31.js，那么您可能使用的是1.0.3之前的版本，因为从1.0.3开始，主js文件被重命名为paho-mqtt.js。这可能是您的代码中某些内容与HiveMQ版本工作方式不同的原因。

我试图总结一下这里的情况