Where should I open / close JMS connections in a JSF ManagedBean?
In a simple demo web app using JSF 2 and Ajax, there is a method in the ManagedBean which receives messages from a JMS queue:
@ManagedBean
public class Bean {
@Resource(mappedName = "jms/HabariConnectionFactory")
private ConnectionFactory connectionFactory;
@Resource(mappedName = "jms/TOOL.DEFAULT")
private Queue queue;
public String getMessage() {
String result = "no message";
try {
Connection connection = connectionFactory.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageConsumer consumer = session.createConsumer(queue);
Message message = consumer.receiveNoWait();
if (message != null) {
result = ((TextMessage) message).getText();
}
connection.close();
} catch (JMSExcept开发者_StackOverflowion ex) {
Logger.getLogger(Bean.class.getName()).log(Level.SEVERE, null, ex);
}
return result;
}
}
The JMS connection is opened / closed every time the getMessage() method is invoked. Which options do I have to open and close the JMS connection only once in the bean life cycle, to avoid frequent connect/disconnect operations?
First, move your Connection
to be a instance variable so that it can be accessed from your open, close, and getMessage
methods.
Next, create an openConnection
method with the PostConstruct
annotation.
@PostConstruct
public void openConnection() {
connection = connectionFactory.createConnection();
}
Finally, create a closeConnection
method with the PreDestroy
annotation.
@PreDestroy
public void closeConnection() {
connection.close();
}
How about in the servlet context listener?
Just define in web.xml
<listener>
<listener-class>contextListenerClass</listener-class>
</listener>
And then implement a servletContextListener
public final class contextListenerClassimplements ServletContextListener {
...
}
Other solution can be to use SessionListener...
精彩评论