如前所述,JMS分兩大類:PTP和Pub/Sub
主要的幾個(gè)對(duì)象:ConnectionFactory、Connection、Destination、Session、MessageProducer、MessageConsumer
其相互關(guān)系如下圖:
1.PTP:
簡單回顧7個(gè)對(duì)象:QueueConnectionFactory、QuequeConnection、Queue、QueueSession、QueueSender、QueueReceiver、QueueBrowser
1) Sender
try {
//具體怎么得到就不寫了,各個(gè)系統(tǒng)肯定都不一樣,但終究都是通過jdni來獲得
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為要傳輸?shù)膶?duì)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,就收拾干凈
publisher.close();
session.close();
connection.close();
} catch (JMSException e) {
//TODO
} finally {
publisher = null;
session = null;
connection = null;
}
2) Receiver/Browser
a.主動(dòng)接收,synchronously
try {
QueueReceiver receiver = session.createReceiver(queue);
receiver.receiveNoWait();
/**
QueueBrowser browser = session.createBrowser(queue); //QueueBrowser只會(huì)取消息,但不會(huì)取走消息
Enumeration elements = browser.getEnumeration();
while(elements.hasMoreElements) {
Message message = elements.nextElement();
...
}
*/
} catch (JMSException e) {
...
}
b.消息偵聽,也是最主要的應(yīng)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:
簡單回顧6個(gè)對(duì)象:TopicConnectionFactory、TopicConnection、Topic、TopicSession、TopicPublisher、TopicSubscriber
1) Publisher
try {
//具體怎么得到就不寫了,各個(gè)系統(tǒng)肯定都不一樣,但終究都是通過jdni來獲得
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表示不使用事務(wù)
Message objMessage = session.createObjectMessage();
objMessage.setObject((Serializable)obj); //obj為要傳輸?shù)膶?duì)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.主動(dòng)接收,比如上面發(fā)送完后,接收回應(yīng)消息,相當(dāng)于同步接收了
try {
TopicSubscriber subscriber = session.createSubScriber(topic);
message = subscriber.receiver(timeout); //long timeout = ...
subscriber.close();
} catch (JMSException e) {
...
}
b.消息偵聽,asynchronously
try {
...
TopicSubscriber subscriber = session.createSubScriber(topic);
MessageListener listener = new MyListener();
subscriber.setMessageListener(listener); //關(guān)鍵在于這個(gè)listener
connection.start();
} catch (JMSException e) {
...
}
MyListener實(shí)現(xiàn)同上
posted on 2008-08-03 18:04
EvanLiu 閱讀(932)
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