好久没来写博客了，感觉自己堕落了，哈哈，LZ糊里糊涂的又换了家单位，空余时间研究了一下nodejs，顺势搞了这个demo，今天来聊聊基于nodejs和activeMQ的消息推送，内容不算复杂，新手也能一看即会。
首先介绍下一点背景，为什么搞这个东西，LZ上家公司是做监控项目的，很多告警都要实时推送到web端，以前的技术架构是flex+corba+mq(自己封装的)，早期B/S架构的实时推送无非就两种，一个是基于插件的长连接，另外一个就是轮训或者Comet，前者受限于flash技术的衰败肯定会逐渐退出历史舞台，后者的低效率在数据量较大的情况下有随时崩溃的可能。随着html5的web socket技术的产生，很多前端socket技术，例如socket.io逐步得到重用，配合nodejs使用，一个前后端socket连接就可以很轻松地解决问题。
本篇使用技术socket.io+nodeJs+stomp+activeMQ，具体的技术简介就不贴了，各位可以在网络上轻松找到，这里直接代码开路。首先是页面index.htm
<html>
<head>
<style type="text/css">
#messages { padding: 0px; list-style-type: none;}
#messages li { padding: 2px 0px; border-bottom: 1px solid #ccc; }
</style>
<script src="http://code.jquery.com/jquery-1.7.1.min.js"></script>
<script src="/socket.io/socket.io.js"></script>
<script>
$(function() {
var socket = io.connect();
socket.on('connect', function() {
//
});
socket.on('message', function(message) {
$('#messages').append($('<li></li>').text(message));
});
socket.on('disconnect', function() {
$('#messages').append('<li>Disconnected</li>');
});
});
</script>
</head>
<body>
<ul id="messages"></ul>
<hr>
</body>
</html>
代码中的/socket.io/socket.io.js，不是真实存在的，是nodejs加载的socket.io模块，这个插件需要在nodejs中进行添加，命令如下：
npm install socket.io
接下来是nodejs端代码，运行该代码前，要首先启动activeMQ，保证activeMQ，监听了stomp协议和61613端口，LZ在这方面吃了亏，浪费了好长时间，配置文件目录：apache-activemq-5.8.0\conf\activemq.xml
<transportConnectors>
<!-- DOS protection, limit concurrent connections to 1000 and frame size to 100MB -->
<transportConnector name="openwire" uri="tcp://0.0.0.0:61616?maximumConnections=1000&wireformat.maxFrameSize=104857600"/>
<transportConnector name="amqp" uri="amqp://0.0.0.0:5672?maximumConnections=1000&wireformat.maxFrameSize=104857600"/>
<transportConnector name="stomp" uri="stomp://0.0.0.0:61613?maximumConnections=1000&wireformat.maxFrameSize=104857600"/>
</transportConnectors>
var Stomp = require('stomp-client');
var destination = '/topic/myTopic';
var client = new Stomp('127.0.0.1', 61613, 'user', 'pass');
var fs = require('fs'),
http = require('http'),
sio = require('socket.io');
var server = http.createServer(function(req, res) {
res.writeHead(200, { 'Content-type': 'text/html' });
res.end(fs.readFileSync('./index.htm'));
});
server.listen(8888, function() {
console.log('Server listening at http://localhost:8888/');
});
// Attach the socket.io server
io = sio.listen(server);
var tempSockets = [];
io.sockets.on('connection', function(socket) {
console.log('socket connection success!!!');
tempSockets.push(socket);
socket.on('disconnect',function(){
});
});
client.connect(function(sessionId) {
client.subscribe(destination, function(body, headers) {
console.log('From MQ:', body);
//tempSocket.broadcast.emit('message', body);
tempSockets.forEach(function(socket) {
if(socket.connected)
{
socket.send(body);
}
})
});
var i = 0;
function publish(){
setTimeout(function(){
client.publish(destination, 'Hello World!'+(i++));
//publish();
},1000);
}
publish();
});
文中的stomp-client模块也需要nodejs添加
npm install stomp-client
上面代码中，client.publish(destination, 'Hello World!'+(i++))，是nodejs作为提供者向activeMQ发送消息，实际应用中是java端的提供者，代码如下：
package com.feng.activemq;
import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnectionFactory;
/**
* @author songfeng
* @version 1.0.
*/
public class SendMessage
{
private static final String url = "tcp://localhost:61616";
private static final String QUEUE_NAME = "choice.queue";
private static final String TOPIC_NAME = "myTopic";
protected String expectedBody = "<hello>world!</hello>";
public void sendMessage() throws JMSException
{
Connection connection = null;
MessageProducer producer = null;
Session session = null;
try
{
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory(url);
connection = (Connection) connectionFactory.createConnection();
connection.start();
session = (Session) connection.createSession(false,
Session.AUTO_ACKNOWLEDGE);
//Destination destination = session.createQueue(QUEUE_NAME);
Destination destination = session.createTopic(TOPIC_NAME);
producer = session.createProducer(destination);
for(int i = 1 ; i <= 20; i++)
{
TextMessage message = session.createTextMessage(expectedBody+i);
message.setStringProperty("headname", "remoteB");
producer.send(message);
Thread.sleep(1000l);
}
}
catch (Exception e)
{
e.printStackTrace();
}
finally
{
producer.close();
session.close();
connection.close();
}
}
public static void main(String[] args)
{
SendMessage sendMsg = new SendMessage();
try
{
sendMsg.sendMessage();
}
catch (Exception ex)
{
System.out.println(ex.toString());
}
}
}
是不是很简单，重要的是研究的过程，哈哈，继续撸码。。。