This example shows you how to configure a JMS queue with static message selectors (filters).
Static message selectors are HornetQ's extension to message selectors as defined in JMS spec 1.1. Rather than specifying the selector in the application code, static message selectors are defined in one of HornetQ's configuration files, hornetq-jms.xml, as an element called 'selector' inside each JMS queue definition:
<queue name="selectorQueue">
<entry name="/queue/selectorQueue">
<selector string="color='red'"/>
</queue>
Once configured the queue selectorQueue only delivers messages that are
that match the selector; i.e. only the messages whose color property is equal to 'red' can be received by its consumers.
Those that don't match the selector will be dropped by the queue and therefore will never be delivered to any of its consumers.
In the example code, five messages with different color property values are sent to queue selectorQueue.
One consumer is created to receive messages from the queue. Of the five sent messages, two have a color property
set to 'red', one has it set to 'blue', another to 'green',
and one has not the color property at all. The result is that the consumer only gets the two messages
with the 'red' color.
To run the example, simply type ./build.sh (or build.bat on windows) from this directory
client-jndi.properties file in the directory ../common/config
InitialContext initialContext = getContext();
Queue queue = (Queue) initialContext.lookup("/queue/selectorQueue");
ConnectionFactory cf = (ConnectionFactory) initialContext.lookup("/ConnectionFactory");
connection = cf.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageProducer producer = session.createProducer(queue);
MessageConsumer redConsumer = session.createConsumer(queue);
redConsumer.setMessageListener(new SimpleMessageListener("red"));
TextMessage redMessage1 = session.createTextMessage("Red-1");
redMessage1.setStringProperty("color", "red");
TextMessage redMessage2 = session.createTextMessage("Red-2");
redMessage2.setStringProperty("color", "red");
TextMessage greenMessage = session.createTextMessage("Green");
greenMessage.setStringProperty("color", "green");
TextMessage blueMessage = session.createTextMessage("Blue");
blueMessage.setStringProperty("color", "blue");
TextMessage normalMessage = session.createTextMessage("No color");
producer.send(redMessage1);
System.out.println("Message sent: " + redMessage1.getText());
producer.send(greenMessage);
System.out.println("Message sent: " + greenMessage.getText());
producer.send(blueMessage);
System.out.println("Message sent: " + blueMessage.getText());
producer.send(redMessage2);
System.out.println("Message sent: " + redMessage2.getText());
producer.send(normalMessage);
System.out.println("Message sent: " + normalMessage.getText());
Thread.sleep(5000);
finally block. Closing a JMS connection will automatically close all of its sessions, consumers, producer and browser objects
finally
{
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}