To Produce Messages

1. Get a connection factory.

   A Message Queue ConnectionFactory object encapsulates all of the needed configuration properties for creating connections to the Message Queue message service. You can obtain such an object either by direct instantiation.

   ConnectionFactory myFctry = new com.sun.messaging.ConnectionFactory();

   or by looking up a predefined connection factory using the Java Naming and Directory Interface (JNDI). In the latter case, all of the connection factory’s properties will have been preconfigured to the appropriate values by your Message Queue administrator. If you instantiate the factory object yourself, you may need to configure some of its properties explicitly: for instance,

   myFctry.setProperty(ConnectionConfiguration.imqAddressList, "localhost:7676, broker2:5000, broker3:9999"); myFctry.setProperty(ConnectionConfiguration.imqReconnectEnabled, "true");

   See Obtaining a Connection Factory for further discussion.

2. Create a connection.

   A Connection object is an active connection to the Message Queue message service, created by the connection factory you obtained in Developing a Client Application:

   Connection myConnection = myFactory.createConnection();

   See Using Connections for further discussion.

3. Create a session for communicating with the message service.

   A Session object represents a single-threaded context for producing and consuming messages. Every session exists within the context of a particular connection and is created by that connection’s createSession method:

   Session mySession = myConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);

   The first (boolean) argument specifies whether the session is transacted. The second argument is the acknowledgment mode, such as AUTO_ACKNOWLEDGE, CLIENT_ACKNOWLEDGE, or DUPS_OK_ACKNOWLEDGE; these are defined as static constants in the JMS Session interface. See Acknowledgment Modes and Transacted Sessions for further discussion.

4. Get a destination to which to send messages.

   A Destination object encapsulates provider-specific naming syntax and behavior for a message destination, which may be either aqueue or a point-to-point publish/subscribe topic (see Messaging Domains). You can obtain such an object by direct instantiation

   Destination myDest = new com.sun.messaging.Queue("myDest");

   or by looking up a predefined destination using the JNDI API. See Working With Destinations for further discussion.

5. Create a message producer for sending messages to this destination.

   A MessageProducer object is created by a session and associated with a particular destination:

   MessageProducer myProducer = mySession.createProducer(myDest);

   See Sending Messages for further discussion.

6. Create a message.

   A Session object provides methods for creating each of the six types of message defined by JMS: text, object, stream, map, bytes, and null messages. For instance, you can create a text message with the statement

   TextMessage outMsg = mySession.createTextMessage();

   See Composing Messages for further discussion.

7. Set the message’s content and properties.

   Each type of message has its own methods for specifying the contents of the message body. For instance, you can set the content of a text message with the statement

   outMsg.setText("Hello, World!");

   You can also use the property mechanism to define custom message properties of your own: for instance,

   outMsg.setStringProperty("MagicWord", "Shazam");

   See Working With Messages for further discussion.

8. Send the message.

   The message producer’s send method sends a message to the destination with which the producer is associated:

   myProducer.send(outMsg);

   See Sending Messages for further discussion.

9. Close the session.

   When there are no more messages to send, you should close the session

   mySession.close();

   allowing Message Queue to free any resources it may have associated with the session. See Working With Sessions for further discussion.

10. Close the connection.

    When all sessions associated with a connection have been closed, you should close the connection by calling its close method:

    myConnection.close();

    See Using Connections for further discussion.