如前所述,JMS分两大类:PTP和Pub/Sub
主要的几个对象:ConnectionFactory、Connection、Destination、Session、MessageProducer、MessageConsumer
其相互关系如下图:
1.PTP:
简单回顾7个对象:QueueConnectionFactory、QuequeConnection、Queue、QueueSession、QueueSender、QueueReceiver、QueueBrowser
1) Sender
try {
//具体怎么得到就不写了,各个系统肯定都不一样,但终究都是通过jdni来获得
Context jndiContext = new InitialContext();
QueueConnectionFactory factory = jndiContext.lookup("**Factory");
Queue queue = jndiContext.lookup("**Queue");
QueueConnection connection = factory.createQueueConnection();
boolean transaction = true;
QueueSession session = connection.createQueueSession(transaction , Session.AUTO_ACKNOWLEDGE);
Message objMessage = session.createObjectMessage(); //或session.createTextMessage("...");
objMessage.setObject((Serializable)obj); //obj为要传输的对象
QueueSender sender = session.createSender(queue);
publisher.setTimeToLive(timeout); //long timeout = ...
connection.start();
sender.send(objMessage);
//or
/**
sender = session.createSender(null);
sender.send(queue, message);
*/
//如果不用了,就收拾干净
publisher.close();
session.close();
connection.close();
} catch (JMSException e) {
//TODO
} finally {
publisher = null;
session = null;
connection = null;
}
2) Receiver/Browser
a.主动接收,synchronously
try {
QueueReceiver receiver = session.createReceiver(queue);
receiver.receiveNoWait();
/**
QueueBrowser browser = session.createBrowser(queue); //QueueBrowser只会取消息,但不会取走消息
Enumeration elements = browser.getEnumeration();
while(elements.hasMoreElements) {
Message message = elements.nextElement();
...
}
*/
} catch (JMSException e) {
...
}
b.消息侦听,也是最主要的应用,asynchronously
try {
MessageListener myListener = new MyListener();
QueueReceiver receiver = session.createReceiver(queue);
receiver.setMessageListener(myListener);
connection.start();
} catch (JMSException e) {
...
}
public class MyListener impelments MessageListner {
public void onMessage(Message message) {
if(message instanceof TextMessage) {
...
} else if (message instanceof ObjectMessage) {
...
} else {
...
}
}
}
2.Pub/Sub:
简单回顾6个对象:TopicConnectionFactory、TopicConnection、Topic、TopicSession、TopicPublisher、TopicSubscriber
1) Publisher
try {
//具体怎么得到就不写了,各个系统肯定都不一样,但终究都是通过jdni来获得
Context jndiContext = new InitialContext();
TopicConnectionFactory factory = jndiContext.lookup("**Factory");
Topic topic = jndiContext.lookup("**Topic");
TopicConnection connection = factory.createTopicConnection();
TopicSession session = connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE); //false表示不使用事务
Message objMessage = session.createObjectMessage();
objMessage.setObject((Serializable)obj); //obj为要传输的对象
TopicPublisher publisher = session.createPublisher(topic);
publisher.setTimeToLive(100000);
connection.start();
publisher.publish(message);
//or
/**
publisher = session.createPublisher(null);
publiser.publish(topic, message);
*/
publisher.close();
session.close();
connection.close();
} catch (JMSException e) {
//TODO
}
2) Subscriber
a.主动接收,比如上面发送完后,接收回应消息,相当于同步接收了
try {
TopicSubscriber subscriber = session.createSubScriber(topic);
message = subscriber.receiver(timeout); //long timeout = ...
subscriber.close();
} catch (JMSException e) {
...
}
b.消息侦听,asynchronously
try {
...
TopicSubscriber subscriber = session.createSubScriber(topic);
MessageListener listener = new MyListener();
subscriber.setMessageListener(listener); //关键在于这个listener
connection.start();
} catch (JMSException e) {
...
}
MyListener实现同上
posted on 2008-08-03 18:04
EvanLiu 阅读(923)
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