At least in ActiveMQ what you want is totally supported, his name is VirtualTopic
The concept is:
- You create a VirtualTopic (Simply creating a Topic using the prefix
VirtualTopic. ) eg. VirtualTopic.Color
- Create a consumer subscribing to this VirtualTopic matching this pattern
Consumer.<clientName>.VirtualTopic.<topicName> eg. Consumer.client1.VirtualTopic.Color, doing it, Activemq will create a queue with that name and that queue will subscribe to VirtualTopic.Color then every message published to this Virtual Topic will be delivered to client1 queue, note that it works like rabbitmq exchanges.
- You are done, now you can consume client1 queue like every queue, with many consumers, DLQ, customized redelivery policy, etc.
- At this point I think you understood that you can create client2, client3 and how many subscribers you want, all of them will receive a copy of the message published to
VirtualTopic.Color
Here the code
@Component
public class ColorReceiver {
private static final Logger LOGGER = LoggerFactory.getLogger(MailReceiver.class);
@Autowired
private JmsTemplate jmsTemplate;
// simply generating data to the topic
long id=0;
@Scheduled(fixedDelay = 500)
public void postMail() throws JMSException, IOException {
final Color colorName = new Color[]{Color.BLUE, Color.RED, Color.WHITE}[new Random().nextInt(3)];
final Color color = new Color(++id, colorName.getName());
final ActiveMQObjectMessage message = new ActiveMQObjectMessage();
message.setObject(color);
message.setProperty("color", color.getName());
LOGGER.info("status=color-post, color={}", color);
jmsTemplate.convertAndSend(new ActiveMQTopic("VirtualTopic.color"), message);
}
/**
* Listen all colors messages
*/
@JmsListener(
destination = "Consumer.client1.VirtualTopic.color", containerFactory = "colorContainer"
selector = "color <> 'RED'"
)
public void genericReceiveMessage(Color color) throws InterruptedException {
LOGGER.info("status=GEN-color-receiver, color={}", color);
}
/**
* Listen only red colors messages
*
* the destination ClientId have not necessary exists (it means that his name can be a fancy name), the unique requirement is that
* the containers clientId need to be different between each other
*/
@JmsListener(
// destination = "Consumer.redColorContainer.VirtualTopic.color",
destination = "Consumer.client1.VirtualTopic.color",
containerFactory = "redColorContainer", selector = "color='RED'"
)
public void receiveMessage(ObjectMessage message) throws InterruptedException, JMSException {
LOGGER.info("status=RED-color-receiver, color={}", message.getObject());
}
/**
* Listen all colors messages
*/
@JmsListener(
destination = "Consumer.client2.VirtualTopic.color", containerFactory = "colorContainer"
)
public void genericReceiveMessage2(Color color) throws InterruptedException {
LOGGER.info("status=GEN-color-receiver-2, color={}", color);
}
}
@SpringBootApplication
@EnableJms
@EnableScheduling
@Configuration
public class Config {
/**
* Each @JmsListener declaration need a different containerFactory because ActiveMQ requires different
* clientIds per consumer pool (as two @JmsListener above, or two application instances)
*
*/
@Bean
public JmsListenerContainerFactory<?> colorContainer(ActiveMQConnectionFactory connectionFactory,
DefaultJmsListenerContainerFactoryConfigurer configurer) {
final DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
factory.setConnectionFactory(connectionFactory);
factory.setConcurrency("1-5");
configurer.configure(factory, connectionFactory);
// container.setClientId("aId..."); lets spring generate a random ID
return factory;
}
@Bean
public JmsListenerContainerFactory<?> redColorContainer(ActiveMQConnectionFactory connectionFactory,
DefaultJmsListenerContainerFactoryConfigurer configurer) {
// necessary when post serializable objects (you can set it at application.properties)
connectionFactory.setTrustedPackages(Arrays.asList(Color.class.getPackage().getName()));
final DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
factory.setConnectionFactory(connectionFactory);
factory.setConcurrency("1-2");
configurer.configure(factory, connectionFactory);
return factory;
}
}
public class Color implements Serializable {
public static final Color WHITE = new Color("WHITE");
public static final Color BLUE = new Color("BLUE");
public static final Color RED = new Color("RED");
private String name;
private long id;
// CONSTRUCTORS, GETTERS AND SETTERS
}
