Red Hat Application Server, Руководство пользователя

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Chapter 26. JMS User’s Guide 199
26.2.2. Accessing the Destination Object
Accessing a JMS destination within the code of an application component requires using a
Resource
Environment Reference
, which is represented in the standard deployment descriptor as follows:
Ê
resource-env-ref
Ë
Ê
resource-env-ref-name
Ë
jms/stockQueue
Ê
/resource-env-ref-name
Ë
Ê
resource-env-ref-type
Ë
javax.jms.Queue
Ê
resource-env-ref-type
Ë
Ê
/resource-env-ref
Ë
The application component’s source code should contain:
Queue q = (Queue) ctx.lookup("java:comp/env/jms/stockQueue");
The mapping to the actual JNDI name (for example, "myQueue") is defined in the JOnAS-specific
deployment descriptor in the following way:
Ê
jonas-resource-env
Ë
Ê
resource-env-ref-name
Ë
jms/stockQueue
Ê
/resource-env-ref-name
Ë
Ê
jndi-name
Ë
myQueue
Ê
jndi-name
Ë
Ê
/jonas-resource-env
Ë
26.2.3. Writing JMS Operations
A typical method performing a message-sending JMS operation looks like the following:
void sendMyMessage() {
ConnectionFactory cf = (ConnectionFactory)
ctx.lookup("java:comp/env/jms/conFact");
Queue queue = (Queue) ctx.lookup("java:comp/env/jms/stockQueue");
Connection conn = cf.createConnection();
Session sess = conn.createSession(true, Session.AUTO_ACKNOWLEDGE);
MessageProducer mp = sess.createProducer((Destination)queue);
ObjectMessage msg = sess.createObjectMessage();
msg.setObject("Hello");
sender.send(msg);
sess.close();
conn.close();
}
It is also possible for an application component to synchronously receive a message. Here is an EJB
method that performs synchronous message reception on a queue:
public String recMsg() {
ConnectionFactory cf = (ConnectionFactory)
ctx.lookup("java:comp/env/jms/conFact");
Queue queue = (Queue) ctx.lookup("java:comp/env/jms/stockQueue");
Connection conn = cf.createConnection();
Session sess = conn.createSession(true, Session.AUTO_ACKNOWLEDGE);
MessageConsumer mc = sess.createConsumer((Destination)queue);
conn.start();
ObjectMessage msg = (ObjectMessage) mc.receive();
String msgtxt =
(String) msg.getObject();
sess.close();
conn.close();
return msgtxt;
}