#RabbitListener Not receiving messages from queue - rabbitmq

Question

I am using #RabbitListner annotation to recieve messages from a RabbitMq queue.
Although I have done all steps required to do this (i.e. Add #EnableRabbit annotation in my config class) and declare SimpleRabbitListenerContainerFactory as a bean , still my method is not recieving messages from the queue . Can anybody suggest what I am missing :
I am using Spring Boot to launch my application
My launch class
#Configuration
#EnableAutoConfiguration
#EnableRabbit
#EnableConfigurationProperties
#EntityScan("persistence.mysql.domain")
#EnableJpaRepositories("persistence.mysql.dao")
#ComponentScan(excludeFilters = { #ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, value = ApiAuthenticationFilter.class),#ComponentScan.Filter(type = FilterType.ASSIGNABLE_TYPE, value = ApiVersionValidationFilter.class)},basePackages = {"common", "mqclient","apache", "dispatcher" })
public class Application {
public static void main(final String[] args) {
final SpringApplicationBuilder appBuilder = new SpringApplicationBuilder(
Application.class);
appBuilder.application().setWebEnvironment(false);
appBuilder.profiles("common", "common_mysql_db", "common_rabbitmq")
.run(args);
}
#Bean
#Primary
#ConfigurationProperties(prefix = "spring.datasource")
public DataSource primaryDataSource() {
return DataSourceBuilder.create().build();
}
}
Here is my Bean to define SimpleRabbitListenerContainerFactory inside a component class
#Component(value = "inputQueueManager")
public class InputQueueManagerImpl extends AbstractQueueManagerImpl {
..///..
#Bean(name = "inputListenerContainerFactory")
public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory()
{
SimpleRabbitListenerContainerFactory factory = new
SimpleRabbitListenerContainerFactory();
factory.setConnectionFactory(this.rabbitConnectionFactory);
factory.setConcurrentConsumers(Integer.parseInt(this.concurrentConsumers));
factory.setMaxConcurrentConsumers(Integer.parseInt(this.maxConcurrentConsumers));
factory.setMessageConverter(new Jackson2JsonMessageConverter());
return factory;
}
}
And finally my Listener inside another Controller component
#Controller
public class RabbitListner{
#RabbitListener(queues = "Storm1", containerFactory = "inputListenerContainerFactory")
#Override
public void processMessage(QueueMessage message) {
String topic = message.getTopic();
String payload = message.getPayload();
dispatcher.bean.EventBean eventBean = new dispatcher.bean.EventBean();
System.out.println("Data read from the queue");
Unfortunately , I am sending the messages to the queue but the code inside processMessage is not getting executed ever.
I am not sure what is the problem here . Can anybody help ??

Answer 1

By default, the Json message converter requires hints in the message properties as to what type of object to create.
If your producer does not set those properties, it won't be able to do the conversion without some help.
You can inject a ClassMapper into the converter.
The framework provides a DefaultClassMapper which can be customized - either to look at a different message property than the default __TypeId__ property.
If you always want to convert the json to the same object, you can simply set the default type:
DefaultClassMapper classMapper = newDefaultClassMapper();
classMapper.setDefaultType(QueueMessage.class);
Jackson2JsonMessageConverter converter = new Jackson2JsonMessageConverter();
converter.setClassMapper(classMapper);
factory.setMessageConverter(new Jackson2JsonMessageConverter());
The documentation already shows how to configure this.