djechelon / spring-jms-connectionfactory-poc

Demo repository for issue

Spring JMS ConnectionFactory POC

This repository contains a demo application to simplify an issue occurred with the @ConditionalOnBean annotation from Spring Boot.

In this repository, we define an example IntegrationFlow that:

• Reads from entry JMS channel
• Makes the word uppercase
• Outputs the result to exit JMS channel

The IntegrationFlow depends on the jakarta.jms.ConnectionFactory to have been defined as a bean. In my business case, the Spring Boot application may start without JMS at all, so the IntegrationFlow must not be defined. For that purpose, we use the @ConditionalOnBean annotation.

Per Spring documentation, that annotation should be used only on @AutoConfiguration classes, which makes things a little more complicated. Half of the world uses the same annotation for a variety of purpose, and we are actively using it in our real application to instantiate a bean only if a collaborator is defined as a bean. None of these require that one uses @ConditionalOnBean on @AutoConfigurations only

• Example
• Example

To provide an example, we use a number of _RestService_s that depend on RestTemplate (bearing the root url and authentication info), as well as _SoapService_s depending on WebServiceTemplate, and they depend as such:

• WebServiceTemplate bean depends on business property com.example.ws.{url|username|password}
• SoapService component is annotated @ConditionalOnBean(value = WebServiceTemplate.class, name = "mySpecificWebServiceTemplateBecauseWeHavePlentiesOf")

All beautiful, except that it doesn't work with JMS ConnectionFactory. In this case, the connection factory exists only if spring.artemis.embedded=true (or another MQ broker is defined according to profile configuration).

In this POC, I can see that Spring refuses to instantiate the IntegrationFlow despite the ConnectionFactory exists.

Other considerations:

• In the POC, I have simplified declaring the bean in the application class, but in my application we have dedicated @Configuration classes
• Declaring that Configuration as an @AutoConfiguration(after = JmsAutoConfiguration.class) did not work
• @DependsOn("jmsConnectionFactory") fails when there is no JMS ConnectionFactory
• I can clearly see in the logs that MyJmsConfiguration does not match the Condition
• Debugging into ArtemisAutoConfiguration, the ConnectionFactory eventually is created
• Debugging the test with the BeanFactory, the ConnectionFactory bean is eventually available
• @SpringIntegrationTest is currently not present in the POC but makes no difference (the real application shows it)