Spring autowiring by parameter name does not work for FtpMessageHandlerSpec - spring

Question

I am unable to autowire org.springframework.integration.ftp.dsl.FtpMessageHandlerSpec by using bean name + parameter name that is same as bean name. I believe that Spring should be able to resolve dependencies when there are multiple beans of same type in case that bean name and target parameter name are the same.
I have config like this:
#Configuration
class cfg {
#Bean
Object ftpMessageHandlerSpecUser(
FtpMessageHandlerSpec ftpMessageHandlerSpecA,
FtpMessageHandlerSpec ftpMessageHandlerSpecB
) {
return null;
}
#Bean
FtpMessageHandlerSpec ftpMessageHandlerSpecA() {
return outboundAdapter(() -> null);
}
#Bean
FtpMessageHandlerSpec ftpMessageHandlerSpecB() {
return outboundAdapter(() -> null);
}
}
When I try to run it a get following error:
***************************
APPLICATION FAILED TO START
***************************
Description:
Parameter 0 of method ftpMessageHandlerSpecUser in com.example.demo.cfg required a single bean, but 2 were found:
- &ftpMessageHandlerSpecA: defined by method 'ftpMessageHandlerSpecA' in class path resource [com/example/demo/cfg.class]
- &ftpMessageHandlerSpecB: defined by method 'ftpMessageHandlerSpecB' in class path resource [com/example/demo/cfg.class]
Action:
Consider marking one of the beans as #Primary, updating the consumer to accept multiple beans, or using #Qualifier to identify the bean that should be consumed
When i add #Qualifier to method parameters it works:
#Configuration
class cfg {
#Bean
Object ftpMessageHandlerSpecUser(
#Qualifier("ftpMessageHandlerSpecA") FtpMessageHandlerSpec ftpMessageHandlerSpecA,
#Qualifier("ftpMessageHandlerSpecB") FtpMessageHandlerSpec ftpMessageHandlerSpecB
) {
return null;
}
#Bean
FtpMessageHandlerSpec ftpMessageHandlerSpecA() {
return outboundAdapter(() -> null);
}
#Bean
FtpMessageHandlerSpec ftpMessageHandlerSpecB() {
return outboundAdapter(() -> null);
}
}
This works:
#Configuration
class cfg2 {
#Bean
Object foo(
String beanA,
String beanB
) {
return null;
}
#Bean
String beanA() {
return "beanA";
}
#Bean
String beanB() {
return "beanB";
}
}
Why it does not work with FtpMessageHandlerSpec from spring integration?

Answer 1

DSL *Specs are FactoryBeans for the underlying SI components; hence the leading & on the bean name, so you need a #Qualifier.
Exactly what are you trying to achieve by injecting these anyway? They are simply building blocks for integration flows.