前一段时间工作中经常使用到Apache ActiveMQ用作消息传输。今天在公司不是很忙，于是又深入研究了一下，总结一下分享出来。
基于ActiveMQ的Java客户端实现例子。
接口定义：
public interface MQService {
public void start();
public void sendQueueMessage(String text) throws JMSException;
public void publishTopicMessage(String text) throws JMSException;
public void destroy();
}实现类(部分代码折行了，大家将就着看吧)：
public class ActiveMQServiceImpl implements MQService {
private static final Logger LOGGER = LoggerFactory.getLogger(ActiveMQServiceImpl.class);
private static MQService instance = null;
private InitialContext initialContext;
private QueueConnectionFactory queueConnectionFactory;
private QueueConnection queueConnection;
private QueueSession queueSession;
private Queue queue;
private QueueSender queueSender;
private QueueReceiver queueReceiver;
private TopicConnectionFactory topicConnectionFactory;
private TopicConnection topicConnection;
private TopicSession topicSession;
private Topic topic;
private TopicPublisher topicPublisher;
private TopicSubscriber topicSubscriber;
protected ActiveMQServiceImpl() {
try {
initialContext = new InitialContext(getInitalContextTable());
initQueue();
initTopic();
LOGGER.info("AMQ init complete!");
} catch (Exception e) {
LOGGER.error("failed to connect mq:",e);
}
}
private static Hashtable<String,String> getInitalContextTable(){
Hashtable<String,String> table=new Hashtable<String,String>();
table.put("java.naming.factory.initial", (String)ConfigProject.AMQ_CONFIG.getString("java.naming.factory.initial"));
table.put("java.naming.provider.url", (String)ConfigProject.AMQ_CONFIG.getString("java.naming.provider.url"));
return table;
}
public static MQService getInstance(){
if(instance==null){
instance = new ActiveMQServiceImpl();
return instance;
}
return instance;
}
protected void initQueue() throws Exception{
LOGGER.info("initQueue begin...");
//获取queueConnectionFactory,通过javax.jms.ConnectionFactory.
queueConnectionFactory = (QueueConnectionFactory) initialContext.lookup("ConnectionFactory");
//创建queueConnection
if (ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.principal")!=null) {
queueConnection = queueConnectionFactory.createQueueConnection(
(String)ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.principal"),
(String)ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.credentials")
);
} else {
queueConnection = queueConnectionFactory.createQueueConnection();
}
//设置queueConnection的clientId持久化消息
String clientID = "queue@";
try {
clientID += InetAddress.getLocalHost();
} catch (Exception e) {
clientID += UUID.randomUUID().toString();
}
queueConnection.setClientID(clientID);
//创建queueSession
queueSession = queueConnection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
//创建queue
queue = queueSession.createQueue((String)ConfigProject.AMQ_CONFIG.getProperty("test.notification.queue"));
//创建queueSender发送消息
queueSender = queueSession.createSender(queue);
//设置消息是否持久化:如果消费端没有接收到消息,设置持久化后即使AMQ服务器重启,消费端启动后也会收到消息.
//如果设置非持久化,消息只保存在AMQ服务器内存中,一旦服务器重启,消费端将收不到消息.
queueSender.setDeliveryMode(DeliveryMode.PERSISTENT);
//创建queueReceiver接收消息
queueReceiver = queueSession.createReceiver(queue);
queueReceiver.setMessageListener(new QueueReceiveListener());
LOGGER.info("initQueue end...");
}
protected void initTopic() throws Exception{
LOGGER.info("initTopic begin...");
//获取topicConnectionFactory
topicConnectionFactory = (TopicConnectionFactory) initialContext.lookup("ConnectionFactory");
//创建topicConnection
if (ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.principal") != null) {
topicConnection = topicConnectionFactory.createTopicConnection(
(String)ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.principal"),
(String)ConfigProject.AMQ_CONFIG.getProperty("java.naming.security.credentials"));
} else {
topicConnection = topicConnectionFactory.createTopicConnection();
}
//设置clientId
String clientID = "topic@";
try {
clientID += InetAddress.getLocalHost();
} catch (Exception e) {
clientID += UUID.randomUUID().toString();
}
topicConnection.setClientID(clientID);
//创建topicSession
topicSession = topicConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
//创建topic
topic = topicSession.createTopic((String)ConfigProject.AMQ_CONFIG.getProperty("test.notification.topic"));
//创建发布者
topicPublisher = topicSession.createPublisher(topic);
topicPublisher.setDeliveryMode(DeliveryMode.PERSISTENT);
//创建消费者
topicSubscriber = topicSession.createSubscriber(topic);
topicSubscriber.setMessageListener(new TopicReciverListener());
LOGGER.info("initTopic end...");
}
public void start() {
if(queueConnection!=null)
{
try {
queueConnection.start();
} catch (JMSException e) {
LOGGER.error("failed to start queue connection!",e);
}
}
if(topicConnection!=null)
{
try {
topicConnection.start();
} catch (JMSException e) {
LOGGER.error("failed to start topic connection!",e);
}
}
}
public void sendQueueMessage(String text) throws JMSException {
queueSender.send(queueSession.createTextMessage(text));
}
public void publishTopicMessage(String text) throws JMSException {
topicPublisher.publish(topicSession.createTextMessage(text));
}
public void destroy() {
try {
this.queueSender.close();
this.queueReceiver.close();
this.queueSession.close();
this.queueConnection.close();
this.topicPublisher.close();
this.topicSubscriber.close();
this.topicSession.close();
this.topicConnection.close();
this.initialContext.close();
} catch (NamingException e) {
LOGGER.warn("failed to shutdown mq", e);
} catch (Exception e) {
LOGGER.warn("failed to shutdown mq", e);
}
}
}上面程序中：
ConfigProject是个配置工具类，读取properties中的AMQ配置信息。
JNDI初始化InitialContext时一定要注意加载amq的InitialContextFactory和请求url地址。
java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory
java.naming.provider.url=failover://(nio://1x.xx.xx.x3:61616,nio://1x.xx.xx.x4:61616)randomize=false
日志用的是logback+slf4j这2个开源组件。
QueueReceiveListener是队列消费端的监听器，TopicReciverListener是主题订阅者的监听器。
QueueReceiveListener.java：
/**
* 消息监听类:
* 如果需要回复,则可以作为内部类实现.
*/
public class QueueReceiveListener implements MessageListener{
private static final Logger LOGGER = LoggerFactory.getLogger(QueueReceiveListener.class);
public void onMessage(Message message) {
LOGGER.info("QueueReceiveListener onMessage begin...");
try{
if(message instanceof TextMessage){
TextMessage textMessage = (TextMessage) message;
LOGGER.info("textMessage:"+textMessage.getText());
}
}catch(Exception e){
e.printStackTrace();
}
LOGGER.info("QueueReceiveListener onMessage end...");
}
}TopicReciverListener.java：
public class TopicReciverListener implements MessageListener{
private static final Logger LOGGER = LoggerFactory.getLogger(TopicReciverListener.class);
public void onMessage(Message message) {
LOGGER.info("TopicReciverListener onMessage begin...");
try{
if(message instanceof TextMessage){
TextMessage textMessage = (TextMessage) message;
LOGGER.info("textMessage:"+textMessage.getText());
}
}catch(Exception e){
e.printStackTrace();
}
LOGGER.info("TopicReciverListener onMessage end...");
}
}同样，这两个监听类也可以通过内部类的形式写在实现类内部，例如需要回复收到的消息时。此处因为没有回复消息的功能，所以就单独写了一个类。
最后，定义一个工具类方便调用：
public class MQServiceUtils {
//此处同样可以使用IoC框架注入
private static MQService mqService = ActiveMQServiceImpl.getInstance();
public static void sendMessage(String message){
try{
mqService.sendQueueMessage(message);
}catch(Exception e){
e.printStackTrace();
}
}
public static void publishMessage(String message){
try{
mqService.publishTopicMessage(message);
}catch(Exception e){
e.printStackTrace();
}
}
}
附一些不错的参考资料：
http://www.iteye.com/topic/836509 基于ActiveMQ 的发布/订阅实例
http://wenku.baidu.com/view/a41c0a29bd64783e09122bbb.htmls p2p/topic开发流程.
http://wenku.baidu.com/view/6c763565f5335a8102d22059.html AMQ PPT文档.
http://wenku.baidu.com/view/4e63b6dbad51f01dc281f10d.html AMQ in Action中文版
http://www.huaishao8.com/config/activemq/143.html AMQ使用详解(连载)
http://wenku.baidu.com/view/a41c0a29bd64783e09122bbb.htmls ActiveMQ教程
