Writing a Node.js Client to Send/Receive messages with WSO2 Messge Broker

WSO2 Message Broker supports AMQP protocol 0-9-1. If you need to use Node.js client to publish/subscribe to Message Broker this can be done with using any compatible Node.js AMQP 0-9-1 Client Library. Some of the examples i found are,

1. amqp.node : https://github.com/squaremo/amqp.node
2. node-amqp : https://github.com/postwait/node-amqp

First of all we need to install Node.js if we haven't done it yet. The following page explains how to install Node.js in Ubuntu.

$ sudo apt-get install python-software-properties python g++ make 

$ sudo add-apt-repository ppa:chris-lea/node.js 

$ sudo apt-get update $ sudo apt-get install nodejs

Then add 'amqplib' module to get enable the functions in 'node.amqp' library.

$ npm install amqplib

The following sample code, written using amqp.node library can be used now as a NodeJS client to publish or receive messages from WSO2 Message Broker. You have to use the format amqp://{username}:{password}@{hostname}:{port} to establish a connection with Message Broker. All messages will be sent as byte messages but can be received as text.

'amqp.node' library provide a rich API which can be used to other Queue operations MB too.

  

A Sample Node.js Queue Publisher for WSO2 MB

    
    var queuename = 'MyQueue'; 

    var openConn = require('amqplib').connect('amqp://admin:admin@localhost:5672'); 

    // amqp://{username}:{password}@{hostname}:{port} is default AMQP connection URL of WSO2 MB 

    openConn.then(function(conn) { 

    var ok = conn.createChannel(); 

    ok = ok.then(function(channel) 

    { channel.assertQueue(queuename); 

    channel.sendToQueue(queuename, new Buffer('New Message')); }); 

    return ok; 

    }).then(null, console.warn);  

A Sample Node.js Queue Consumer for WSO2 MB

var queuename = 'MyQueue'; 

    var openConn = require('amqplib').connect('amqp://admin:admin@localhost:5672'); 

    // amqp://{username}:{password}@{hostname}:{port} is default AMQP connection URL of WSO2 MB 

    openConn.then(function(conn) { 

    var ok = conn.createChannel(); 

    ok = ok.then(function(channel) { 

           channel.assertQueue(queuename); 

    channel.consume(queuename, function(msg) { 

    console.log(msg.content.toString()); 

    channel.ack(msg); }); 

    }); 

    return ok; 

    }).then(null, console.warn);