ActiveMQ学习教程（一）——安装与示例

背景：ActiveMQ 是Apache出品，最流行的，能力强劲的开源消息总线。

选择ActiveMQ作为JMS的入门学习中间件，是因为其拥有以下优点

1.多种语言和协议编写客户端。语言: Java, C, C++, C#, Ruby, Perl, Python, PHP。应用协议: OpenWire,Stomp REST,WS Notification,XMPP,AMQP

2.完全支持JMS1.1和J2EE 1.4规范 (持久化,XA消息,事务)

3.对Spring的支持,ActiveMQ可以很容易内嵌到使用Spring的系统里面去,而且也支持Spring2.0的特性

4.完全支持JMS1.1和J2EE 1.4规范 (持久化,XA消息,事务)

5.通过了常见J2EE服务器(如 Geronimo,JBoss 4, GlassFish,WebLogic)的测试,其中通过JCA 1.5 resource adaptors的配置,可以让ActiveMQ可以自动的部署到任何兼容J2EE 1.4 商业服务器上

6.支持多种传送协议:in-VM,TCP,SSL,NIO,UDP,JGroups,JXTA

7.从设计上保证了高性能的集群,客户端-服务器,点对点

8.支持Ajax

9.支持与Axis的整合

10.可以很容易得调用内嵌JMS provider,进行测试

学会了ActiveMQ之后，其它供应商的MQ也可以在短时间内快速上手。

安装：

ActiveMQ（本文简称MQ）要求JDK1.5以上，推荐1.6以上版本。还没安装JDK的朋友，请先安装，在此不赘诉了。

安装完JDK后，从 http://activemq.apache.org/download.html下载MQ的最新版本，本教程使用版本为5.5。

解压后，可以看到MQ目录下有以下文件和目录

activemq-all-5.5.0.jar:所有MQ JAR包的集合，用于用户系统调用

bin:其中包含MQ的启动脚本

conf:包含MQ的所有配置文件

data:日志文件及持久性消息数据

example:MQ的示例

lib:MQ运行所需的所有Lib

webapps:MQ的Web控制台及一些相关的DEMO

启动MQ：

双击bin目录下的activemq.bat文件即可启动MQ

第一个示例：

新建一个JAVA工程，引用activemq-all-5.5.0.jar，SLFAPI其及对应版本LOG4J的JAR包（懒的上网找的到附件里下载）

Publisher.java

Java代码


import java.util.Hashtable;

import java.util.Map;

import javax.jms.Connection;

import javax.jms.ConnectionFactory;

import javax.jms.Destination;

import javax.jms.JMSException;

import javax.jms.MapMessage;

import javax.jms.Message;

import javax.jms.MessageProducer;

import javax.jms.Session;

import org.apache.activemq.ActiveMQConnectionFactory;

import org.apache.activemq.command.ActiveMQMapMessage;

public class Publisher {

protected int MAX_DELTA_PERCENT = 1;

protected Map<String, Double> LAST_PRICES = new Hashtable<String, Double>();

protected static int count = 10;

protected static int total;

protected static String brokerURL = "tcp://localhost:61616";

protected static transient ConnectionFactory factory;

protected transient Connection connection;

protected transient Session session;

protected transient MessageProducer producer;

public Publisher() throws JMSException {

factory = new ActiveMQConnectionFactory(brokerURL);

connection = factory.createConnection();

try {

connection.start();

} catch (JMSException jmse) {

connection.close();

throw jmse;

}

session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

producer = session.createProducer(null);

}

public void close() throws JMSException {

if (connection != null) {

connection.close();

}

}

public static void main(String[] args) throws JMSException {

Publisher publisher = new Publisher();

while (total < 1000) {

for (int i = 0; i < count; i++) {

publisher.sendMessage(args);

}

total += count;

System.out.println("Published '" + count + "' of '" + total + "' price messages");

try {

Thread.sleep(1000);

} catch (InterruptedException x) {

}

}

publisher.close();

}

protected void sendMessage(String[] stocks) throws JMSException {

int idx = 0;

while (true) {

idx = (int)Math.round(stocks.length * Math.random());

if (idx < stocks.length) {

break;

}

}

String stock = stocks[idx];

Destination destination = session.createTopic("STOCKS." + stock);

Message message = createStockMessage(stock, session);

System.out.println("Sending: " + ((ActiveMQMapMessage)message).getContentMap() + " on destination: " + destination);

producer.send(destination, message);

}

protected Message createStockMessage(String stock, Session session) throws JMSException {

Double value = LAST_PRICES.get(stock);

if (value == null) {

value = new Double(Math.random() * 100);

}

// lets mutate the value by some percentage

double oldPrice = value.doubleValue();

value = new Double(mutatePrice(oldPrice));

LAST_PRICES.put(stock, value);

double price = value.doubleValue();

double offer = price * 1.001;

boolean up = (price > oldPrice);

MapMessage message = session.createMapMessage();

message.setString("stock", stock);

message.setDouble("price", price);

message.setDouble("offer", offer);

message.setBoolean("up", up);

return message;

}

protected double mutatePrice(double price) {

double percentChange = (2 * Math.random() * MAX_DELTA_PERCENT) - MAX_DELTA_PERCENT;

return price * (100 + percentChange) / 100;

}

}

Consumer.java

Java代码


import javax.jms.Connection;

import javax.jms.ConnectionFactory;

import javax.jms.Destination;

import javax.jms.JMSException;

import javax.jms.MessageConsumer;

import javax.jms.Session;

import org.apache.activemq.ActiveMQConnectionFactory;

public class Consumer {

private static String brokerURL = "tcp://localhost:61616";

private static transient ConnectionFactory factory;

private transient Connection connection;

private transient Session session;

public Consumer() throws JMSException {

factory = new ActiveMQConnectionFactory(brokerURL);

connection = factory.createConnection();

connection.start();

session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

}

public void close() throws JMSException {

if (connection != null) {

connection.close();

}

}

public static void main(String[] args) throws JMSException {

Consumer consumer = new Consumer();

for (String stock : args) {

Destination destination = consumer.getSession().createTopic("STOCKS." + stock);

MessageConsumer messageConsumer = consumer.getSession().createConsumer(destination);

messageConsumer.setMessageListener(new Listener());

}

}

public Session getSession() {

return session;

}

}

Listener.java

Java代码


import java.text.DecimalFormat;

import javax.jms.MapMessage;

import javax.jms.Message;

import javax.jms.MessageListener;

public class Listener implements MessageListener {

public void onMessage(Message message) {

try {

MapMessage map = (MapMessage)message;

String stock = map.getString("stock");

double price = map.getDouble("price");

double offer = map.getDouble("offer");

boolean up = map.getBoolean("up");

DecimalFormat df = new DecimalFormat( "#,###,###,##0.00" );

System.out.println(stock + "\t" + df.format(price) + "\t" + df.format(offer) + "\t" + (up?"up":"down"));

} catch (Exception e) {

e.printStackTrace();

}

}

}

先运行Consumer.java, 输入参数ORCL，然后运行Publisher.java，输入参数ORCL，

就可以看到Publisher在发送消息，Consumer在接收消息了。

（不知道怎么在ECLIPSE里带参数运行程序的，请自行GOOGLE。）

好了，MQ的安装与第一个示例程序的介绍就到此为止了。