How to listen to topic using spring boot jms

Question

I am trying to listen to topic using the below snippet. However its listening to queue by default. There is no xml config in this case. I am completely relying on annotations. Moreover I have relied completely on the AutoConfiguration provided by Spring boot. I am not sure how to set the destination type as topic, In JmsListener. Spring JMS gurus please help.

    @Component
    public class MyTopicListener {

        @JmsListener(destination = "${trans.alert.topic}")
        public void receiveMessage(TransactionAlert alert) {
            logger.info("AlertSubscriberEmail :: Sending Email => <" + alert + ">");
        }
    }

Answer 1

I just took the complete Spring boot example from : https://github.com/spring-guides/gs-messaging-jms/

In this it is created for sending and receipt of messages from a queue. To Change this to a topic , you have to set the Pub-Sub property in the Factory instance.

import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jms.DefaultJmsListenerContainerFactoryConfigurer;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.jms.annotation.EnableJms;
import org.springframework.jms.config.DefaultJmsListenerContainerFactory;
import org.springframework.jms.config.JmsListenerContainerFactory;
import org.springframework.jms.connection.CachingConnectionFactory;
import org.springframework.jms.core.JmsTemplate;
import org.springframework.jms.support.converter.MappingJackson2MessageConverter;
import org.springframework.jms.support.converter.MessageConverter;
import org.springframework.jms.support.converter.MessageType;

import javax.jms.ConnectionFactory;

@SpringBootApplication
@EnableJms
public class JmsSampleApplication {

public void registerBeans(ConfigurableApplicationContext context ){
    BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(JmsTemplate.class);
    CachingConnectionFactory cachingConnectionFactory = new CachingConnectionFactory();

    builder.addPropertyValue("connectionFactory", cachingConnectionFactory);      // set property value
    DefaultListableBeanFactory factory = (DefaultListableBeanFactory) context.getAutowireCapableBeanFactory();
    factory.registerBeanDefinition("jmsTemplateName", builder.getBeanDefinition());
}

@Bean
public JmsListenerContainerFactory<?> topicListenerFactory(ConnectionFactory connectionFactory,
                                                DefaultJmsListenerContainerFactoryConfigurer configurer) {
    DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
    factory.setPubSubDomain(true);
    // This provides all boot's default to this factory, including the message converter
    configurer.configure(factory, connectionFactory);
    // You could still override some of Boot's default if necessary.
    return factory;
}

@Bean
public JmsListenerContainerFactory<?> queueListenerFactory(ConnectionFactory connectionFactory,
                                                           DefaultJmsListenerContainerFactoryConfigurer configurer) {
    DefaultJmsListenerContainerFactory factory = new DefaultJmsListenerContainerFactory();
    //factory.setPubSubDomain(true);
    // This provides all boot's default to this factory, including the message converter
    configurer.configure(factory, connectionFactory);
    return factory;
}

@Bean // Serialize message content to json using TextMessage
public MessageConverter jacksonJmsMessageConverter() {
    MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
    converter.setTargetType(MessageType.TEXT);
    converter.setTypeIdPropertyName("_type");
    return converter;
}
public static void main(String[] args) {
    ConfigurableApplicationContext context = SpringApplication.run(JmsSampleApplication.class, args);

    JmsTemplate jmsTemplate = context.getBean(JmsTemplate.class);

    // Send a message with a POJO - the template reuse the message converter
    System.out.println("Sending an email message.");
    jmsTemplate.convertAndSend("mailbox.topic", new Email("info@example.com", "Hello"));
    jmsTemplate.convertAndSend("mailbox.queue", new Email("info@example.com", "Hello"));

    }
}

The listener

package org.springboot.jms;

import org.springframework.jms.annotation.JmsListener;
import org.springframework.stereotype.Component;

/**
 * Created by RGOVIND on 10/20/2016.
 */
@Component
public class HelloTopicListener {

    @JmsListener(destination = "mailbox.topic", containerFactory = "topicListenerFactory")
    public void receiveTopicMessage(Email email) {
        System.out.println("Received <" + email + ">");
    }

    @JmsListener(destination = "mailbox.queue", containerFactory = "queueListenerFactory")
    public void receiveQueueMessage(Email email) {
        System.out.println("Received <" + email + ">");
    }
}

Once this is done , you are all set to subscribe to the topic of choice.

There are multiple approaches to this of course , you can have a map of beans for different jmsTemplates , each of which can be used when you need them based on queue or topic. The template & beans can be instantiated in a method you choose to like discussed in this SO Question. Hope it helps

Answer 2

The answer marked correct is ALMOST correct. It still wont work because:

factory.setPubSubDomain(true) 

must come AFTER:

configurer.configure(factory, connectionFactory);

Otherwise the pubSubDomain flag being set to true is lost when configuring the defaults and that factory instance will still work with queues and not topics.

Answer 3

In Spring Boot's Application.properties, try setting the following property:

spring.jms.pub-sub-domain=true

Then, use this property for the container factory that you are using to listen to the topic.